Appendix A: Literature Review

Appendix A: Literature Review

11. Overview of literature review

11.1 Background

11.1.1. Transport Scotland (TS), the Scottish Government (SG) and the Department for Transport (DfT) require research evidence and recommendations on methods and approaches to help deliver inclusive design environments within town centres and busy street areas.

11.1.2. This Appendix to the main research report entitled "Inclusive Design in Town Centres and Busy Streets Areas" summarises the findings of the Literature Review undertaken by Napier University. The Literature Review represents Stage 1 of the research study into inclusive design engagement and physical design measures described in the "Inclusive Design in Town Centres and Busy Streets Areas" report.

11.1.3. The complete Edinburgh Napier University Literature Review report is included under Appendix A.1.

11.2 Overview of literature review methodology

11.2.1. The Literature Review was undertaken by the Transport Research Institute at Edinburgh Napier University.

11.2.2. The focus of the Literature Review is to report on peer reviewed and grey literature (non-peer reviewed) addressing the design of town centres and busy streets in the quest for designs which are acceptable to all vulnerable road user categories. This means that papers included needed to have given some attention to those with mobility impairments in order to be included in the Review.

11.2.3. The search criteria are broken down as outlined below:

• Target audiences / populations included in interventions = all adults and children.
• Study design = prioritising reviews of the literature, but also including single studies, including qualitative research.
• Dates = January 2008 to September 2019.
• Geography = global literature search for papers published in English.

Literature searches

11.2.4. Search terms developed by the consultant academic were: inclusive design; shared space; inclusive street design; walk; mobility impairment; sensory impairment; disable; high street; kerb (curb); shopping street; streetscape material; colour (color); texture; surfaces; street delineation; street clutter; tactile pavement / paving; vehicle / pedestrian segregation; disabled parking; bus stop access; severance; pedestrian crossing; traffic speed / volume; accidents; inclusive engagement / consultation; equality engagement / consultation; disability engagement / consultation.

11.2.5. These were augmented by over 100 search words and terms suggested by members of the working group. Some of the new search terms duplicated terms in the above list. In order to attempt to utilise these additional search terms, they were prioritised through discussions within the research team.

11.2.6. Search terms subsequently added were: co-design; wayfinding; street design; shared use; shared surface; delineation; disable / disabilities; blind; partially sighted; deaf-blind; deaf; cognitive impaired; road traffic collision / conflict; access; slope; gradient, pedestrianisation, kerb (curb) height, cycle way.

11.2.7. Search engines used were TRIDS; TRB; ScienceDirect; and Google Scholar. References from studies found were also examined in seeking additional studies. Grey literature was also included such as those drafted by government departments and agencies and road safety institute reports.

11.3 Assessment process

11.3.1. Thirty-eight studies were found to be in scope in this Literature Review. Given that seven of the studies were reviews of the literature, the total number of individual studies referred to is greater than 38. Some single studies also summarised aspects of the literature in setting their own study in the wider context of the shared space literature. After searches had been undertaken to find studies and abstracts, these were checked to assess whether it was likely that they were in scope or out of scope. This involved reading the abstracts and then accessing the full study to read if the abstract suggested that it might be in scope. Seventy studies were read in full.

11.3.2. A common procedure in identifying and examining a body of literature is to group studies under themes. For this Literature Review the themes are:

• Reviews (7).
• Single studies - design and use (23);.
• Single studies - non-visual impairments (2).
• Single studies - engagement and consultation (6).

11.3.3. Each theme is drawn upon in detail in covering the range of topics identified in the Review, in order to set out a cohesive narrative which seeks to draw together the evidence found.

11.3.4. Twenty studies were from the UK, four from elsewhere in Europe and 14 from beyond Europe. All studies are listed with their full citation in the main report (Appendix A.1).

12. Summary and conclusions

12.1 Summary of the literature review findings

12.1.1. There is an array of findings from the Literature Review. At the general level, there needs to be greater recognition of the needs of all users, including people with sight loss (Imrie & Kumar, 2011; Smithies, 2015). The views and feelings of visually impaired people are not a significant part of the policy-making process (Imrie, 2013). There is a need for clear guidelines on how to prevent the identified issues from occurring in newly designed shared spaces and how to improve existing shared-space schemes (Havik et al, 2015; Audrey, Leonards & Damens, 2017). This is supported by Imrie & Kumar (2011) who say that more detailed guidance is required on the development and implementation of shared space.

12.1.2. The seeming lack of consistent standards provides designers with a blank canvas when creating shared-use areas, often meaning that the needs of vulnerable road users, including blind and visually impaired people, are forgotten among the aesthetic details. Shared spaces should not be a uniform material, but distinct safe areas. Boundaries within the shared space should also be present to create an environment that is easily identifiable and understandable to blind and visually impaired people. A consistent approach to designing for blind and visually impaired people should be introduced. This could be achieved by establishing national standards and specifications with appropriate enforcements (Smithies, 2015).

12.1.3. Communication emerges as a challenge to designers and implementers. Communication should be improved (e.g. between guide-dog trainers and roads / highway authorities). Authorities should consult with blind and visually impaired organisations, seeking their opinions before the detailed design stage (Smithies, 2015). As such, roads / highway engineers should be provided with training opportunities to develop their skills in designing for vulnerable road users (Smithies, 2015).

12.1.4. More broadly, a challenge is an expectation of general enjoyment of greater pedestrian space for one group comes at the price of a limited expectation of these benefits for another group. This suggests that even within the broad category of those with impaired mobility, there is not only an accessibility issue, but also a challenge to the equity of the scheme – which would strike at one of the three pillars of sustainability. How would equity be delivered? (Tyler, 2017).

12.1.5. The 'evidence gaps' need to be addressed, particularly in relation to personal safety issues (Imrie & Kumar, 2011).

12.2 Literature review conclusions

12.2.1. The following points represent the main conclusions of the Literature Review:

1. An overall issue is that shared space is contested with claims that disabled users are ignored (Thomas, 2008; Imrie & Kumar, 2011; Imrie, 2013). However, there are studies providing examples of how accessible design can be better achieved through greater efforts at consultation and engagement, especially with groups representing the physically, sensory, and mentally impaired users (Jayakody et al, 2018; Kardacharak, Wilson & Dunn, 2016; Gendron, 2018).

2. There is no agreed definition of 'shared space' (Imrie & Kumar, 2011; Moody & Melia, 2014) and this is reflected by an inconsistent approach to shared-space design (Smithies, 2015). This may be the result of extending the shared space concept beyond implementation in low flow residential areas, to its use in busy urban areas and shopping streets, which has not been thought through (Matthews, Hibberd, Speakman, 2015).

3. There is a clear gap in research into the design of the layout of shared space streets (Kaparios et al, 2012). There is a need for clear guidelines in newly designed shared spaces and how to improve existing shared-space schemes (Havik et al, 2015; Audrey, Leonards & Damens, 2017). More detailed guidance is required on the development and implementation of shared space (Imrie & Kumar, 2011).

4. There is limited high quality (robust) literature on inclusive design aspects from the perspective of those with mobility and / or sensory impairments. In the literature it has been noted that quality scores of most of the articles were low. This might indicate limitations in the methods used and their lack of standardisation (Gamache et al, 2019).

5. There is a paucity of research-based knowledge about the mobility situation of persons with cognitive functional limitations (Gamache et al, 2019) and this is reflected in previous broader transport research.

6. There is evidence that measures which may benefit some users such as visually impaired people can disadvantage other users, e.g. tactile blisters by disrupting the gait of older pedestrians near to crossings. The same is likely of other measures such as the risks that kerbs can for some users be a trip hazard (Naumann et al., 2011 in Norgate, 2012). Only a few of the articles considered more than one type of physical disability (motor, visual or hearing) (six out of 40), meaning that most recommendations were made for individual impairments and not all users (Gamache et al, 2019).

7. There is mixed evidence as to whether the introduction of shared use on high streets and busy streets has increased accidents, but there is a significant number of studies reporting that mobility impaired users are avoiding these areas, noting that most reports are from visually impaired people, e.g. Matthews, Hibberd, Speakman (2015), Tyler, (2017).

8. While the debate about kerb edges is still contested by some, there appears to be a consensus that if not providing kerb edges, then clearly detectable alternative demarcation between motorised traffic and pedestrians is needed (e.g. Havik et al, 2012; Hammond & Musselwhite, 2013).

9. Highway engineers should be provided with training opportunities to develop their skills in designing for vulnerable road users (Smithies, 2015).

10. Highway authorities should consult with a range of mobility impaired organisations, seeking their opinions before the detailed design stage of any proposed shared use scheme is taken forward (Smithies, 2015). It is important, therefore, that this consultation is an ongoing process throughout the design, construction and early operation phases of any implementation (Edquist & Corben, 2012).

11. 'Safe space' areas that are strictly reserved for pedestrians appear to be a well-supported compromise as a design solution and an example of a feature which gives mobility impaired users confidence to engage and move through the shared space (Rombol Nyvig, 2008; Havik et al, 2012; Norgate, 2012; Parkin & Smithies, 2012; Karndacharuk, Wilson & Dunn, 2014).

12.3 Key findings to be considered in subsequent stages

12.3.1. While the level and quality of research available is not extensive and in depth in relation to persons with impairments or combinations of impairments, the literature does present some key findings that should be considered further as part of the research study. These are (with reference to the conclusions set out under section 2.2):

Inclusive engagement:

• LR1 - Inclusive design^[22] can be better achieved through greater efforts at consultation and engagement (pt1).
• LR2 - Engineers and designers should consult with a range of organisations representing users with reduced mobility seeking their opinions on an ongoing basis during the proposal and design stages of all schemes (pt10).

Inclusive physical design measures:

• LR3 - There is mixed evidence as to whether the introduction of shared space use on high streets and busy streets has increased accidents (pt7).
• LR4 - There is research that reports persons with mobility impairment avoid shared space, and most reports relate to visually impaired users (pt7).
• LR5 - The evidence shows that there is still some debate on the need for kerbed edges, however there is consensus that detectable demarcation between motorised traffic and pedestrians in 'shared space' is required (pt8).
• LR6 - 'Safe Space' areas that are strictly reserved for pedestrians appear to be a well-supported compromise as a design solution and give confidence to the user with reduce mobility^[23] (pt11).
• LR7 - There is evidence which suggests that some measures to support some disabled people groups can have an impact on users with other impairments (pt6) and there are limited studies into persons with more than one type of impairment.

The need for more research and definition:

• LR8 - There is no agreed definition of 'shared space' and this is reflected in the inconsistent approach to design (pt2).
• LR9 - There is a need for guidance on street layout for emerging and existing 'shared space' schemes which should be supported by more research (pt3).
• LR10 - There is limited high quality (robust) literature and research on inclusive design from the perspective of the users with mobility and or sensory impairment (pt4).
• LR11 - Limited research exists on mobility experiences of persons with cognitive functional limitations (pt5).

Inclusive design training:

• LR12 - Engineers and designers should have the opportunity to be trained to design for vulnerable road users (pt9).

Appendix A.1

Literature Review Report

Inclusive design on the high street. A literature review of shared space.

Report

Author: Adrian Davis
Quality Assessor: Tom Rye
Date: 16th October 2019

Transport Research Institute
Edinburgh Napier University
Colinton Road
Edinburgh
EH10 4DT

https://blogs.napier.ac.uk/tri/projects/

Suggested citation: Davis. A. 2019. Inclusive Design on the High Street. A Literature Review of Shared Space. Transport Research Institute, Edinburgh Napier University, with WSP, for Transport Scotland.

Background

Transport Scotland is working with the Department for Transport and the Scottish Government Planning and Architecture Division to review current guidance on what makes streets fully accessible for all. This follows the withdrawal and commitment by the Department for Transport to update the Local Transport Note 11/1: Shared Space.

Transport Scotland, the Scottish Government and the Department for Transport have appointed WSP (with support from Napier University and KSO Research) to undertake research into methods and approaches to help deliver inclusive street design environments within town centres and busy street areas.

Aims of the research

The aim of the research is to propose recommendations and key principles on how inclusive engagement approaches, coupled with physical design measures, can provide an inclusive environment for pedestrians / users of our high streets and busy street areas.

The research will present good practice examples ('Case Studies') of schemes within Scotland and England where inclusive design principles have been successfully implemented and which illustrate the principles and recommendations of this research (approaches to inclusive engagement).

Stage approach

The research will be undertaken in stages, with the outcome of each stage informing the subsequent stage. By following this staged approach, it will allow the research team to re-evaluate and reconsider the direction of the document at the end of each stage.

This report forms part of the Stage 1 report of the Inclusive Design in Town Centres and Busy Street Areas study.

Introduction

The objective of the research project is to provide evidence on methods and approaches that help to deliver inclusive design environments within town centres and busy street areas.

The focus of the Literature Review is to report on peer reviewed and grey literature addressing the design of town centres and busy streets in the quest for designs which are acceptable to all vulnerable road user categories. This means that papers included needed to have given some attention to those with mobility impairments in order to be included in the Review.

Target audiences/populations included in interventions.

All adults and children.

Study design

Prioritising reviews of the literature, but also including single studies, including qualitative research.

Dates

January 2008 to September 2019.

Geography

We searched the global literature for papers published in English.

Literature searches

Search terms developed by the consultant academic were: inclusive design; shared space; inclusive street design; walk; mobility impairment; sensory impairment; disable; high street; kerb (curb); shopping street; streetscape material; colour (color); texture; surfaces; street delineation; street clutter; tactile pavement/paving; vehicle/pedestrian segregation; disabled parking; bus stop access; severance; pedestrian crossing; traffic speed/volume; accidents; inclusive engagement / consultation; equality engagement / consultation; disability engagement / consultation.

These were augmented by over 100 search words and terms suggested by members of the key stakeholders' group. Some of the new search terms duplicated terms in the above list. In order to attempt to utilise these additional search terms they were prioritised through discussions within the research team.

Search terms subsequently added were: co-design; wayfinding; street design; shared use; shared surface; delineation; disable/disabilities; blind; partially sighted; deaf-blind; deaf; cognitive impaired; road traffic collision/conflict; access; slope; gradient, pedestrianisation, kerb (curb) height, cycle way.

Search engines used were TRIDS; TRB; ScienceDirect; and Google Scholar. References from studies found were also examined in seeking additional studies. In addition, grey literature was also included such as those drafted by government departments and agencies and road safety institute reports. As well as searching for studies through references and citations in studies found.

13. The literature review in context

Introduction

There is a range of terminology associated with inclusive design and this Literature is focused on a specific geographically contained aspect of it, that is, shared street space on high streets or otherwise busy streets. Coupled with this is the additional specific focus on the ability or not of mobility impaired people to be able to negotiate shared use space with no less confidence that if it were any pavement area where the design enables them to have mobility into and through that space. As Norgate (2012)^[24] states, in terms of designing shared space, one of the requirements is that 'the scheme should be comfortable to use and accessible to disabled.'

This focus is reflected in the array of search terms that have been gathered, prioritised and tested. As reflected in the Literature Review, a challenge has been to identify studies that meet these criteria in order to be accepted as within the scope. A coda is that while there is a significant literature addressing urban shared space (often local high streets) much of this does not include more than cursory reference to impaired mobility e.g. Hamilton Baillie, 2008; Anvari, et al, 2015,^[25] Brookfield, Tilly, 2016,^[26] Hso, C., Lee. T., 2017;^[27] Ruiz-Apilánez et al, 2017 ^[28] Friesen, 2017;^[29] Sukaryavichute, E., Prytherch, D. 2018.^[30]

In setting out the landscape within which the shared space literature resides, we begin with Inclusive Design and draw on studies which are not necessarily in scope for the Literature Review itself either by date or focus or both. Inclusive Design is a design philosophy with the aim of considering the needs and capabilities of the whole population. A central tenet of the philosophy is that through considering the full diversity of users, a better product will result. Inclusive Design aims to engender greater awareness of the fact that it is 'normal to be different' and that great heterogeneity exists in people's capabilities and must be accounted for in good product design. The importance of Inclusive Design is increasing as the populations in many Western countries, including the UK, are ageing.^[31] In general, heterogeneity increases with age and thus, as the population becomes older, the needs and capabilities of users become ever more diverse.^[32]

Like design for special needs, inclusive design requires in-depth insight into how particular groups of people interact with and experience the designed environment. Yet, whereas design for special needs focuses on addressing the needs of these particular groups only, inclusive designs seeks resonance between their needs and the needs of the entire population. Heylighen and colleagues cite Pullin and Newell who describe design resonance as a situation:

"where the needs of the people who have a particular disability coincide with particular able-bodied users in particular contexts".

For example, navigating pavements with a pram or trolley resonates with navigating them with a wheelchair as both benefit from dropped kerbs. Similarly, communicating in a noisy environment resembles the condition of people who are deaf or speech impaired.^[33] By contrast, the relative absence of traffic noise, may be a missing cue for the blind and partly sighted in being sure of where they are. A busy street, researchers note, may be indicated by the sound of street traffic and the frequent use of vehicle horns, while the sound of buses indicates a main street. The sound of people entering or leaving a shop provides information about the presence of shops and may indicate a commercial street. Sounds produced by the interactions of pedestrians with different ground textures are also cited as helpful for determining an environment.^[34]

In the context of design, capability refers to an individual's level of functioning, along a given dimension from very high ability to extreme impairment, which has implications for the extent to which they can interact with products. Drawing on Martens (2018),^[35] the World Health Organisation (WHO) recognises disability "as a complex interaction between features of a person's body and features of the environment and society in which he or she lives." This definition underlines the notion that disability is not simply a characteristic of a person, but rather of the relationship between the particular abilities of a person and the functionalities of his or her environment. In line with this definition, travel impairment should be viewed as a result of human-environment interaction. Thus, people become 'travel impaired' because the transport system does not provide the functionalities necessary to enable people with a particular set of abilities to use the system, thereby limiting their accessibility to destinations. Given the functionalities of the existing transport system, persons may experience three main types of travel-impairments:

• A motor-related impairment (e.g., an impairment resulting from the interaction between a person experiencing difficulty in walking and a poorly accessible transport vehicle).
• A sensory-related impairment (e.g., an impairment resulting from the interaction between a person's limited vision or hearing and a public transport hub that lacks the appropriate specification).
• Cognition-related impairments (e.g., an impairment resulting from the difficulty in comprehending written materials and poorly designed information systems at public transport stops).^[36]

Historically, the design response to questions of capability has often been to accommodate users between the 5th and 95th percentiles of ability. However, this effectively encourages designers to ignore up to 5% of people on each specific capability dimension considered. Given that multiple capabilities are required for interaction with most, if not all, products and that different people tend to populate the extremes of different capability domains (i.e. the group of people who have strength capabilities below the 5th percentile are likely to be different to the group of people who have vision capabilities below the 5th percentile), designing with the 'majority' of users in mind across multiple capability demands often results in products that are difficult or impossible to use for many people. For example, a product that excludes 5% of people on the basis of vision, 5% on the basis of hearing and 5% on the basis of dexterity is highly unlikely to exclude 5% of people overall; rather it is more likely to exclude 10–15% of potential users.

Several authors have pointed out that inclusively designed outdoor spaces play a key role in the engagement of older people in social life. In this context, Elizabeth Burton and Lynne Mitchell introduced the concept of 'streets for life' as a mechanism for achieving the goals of inclusive design at the neighbourhood scale and enabling outdoor environments to be as dementia-friendly as possible.^[37] To this end, they advance six key design principles:

• familiarity,
• legibility,
• distinctiveness,
• accessibility,
• comfort and
• safety.

For example, the diversity of people living with dementia and the varied environments they inhabit generate considerable complexity in designing signage that will actively support their abilities and reduce their disabilities.^[38] For wheelchair users there are other considerations. The most dominant parameter preventing wheelchair mobility is surface condition (material of surface type and the quality of the surface).^[39] Other parameters need to be considered in route calculation such as pavement signs, maximum degree of slope along the path, number of crosswalks and crosswalk types.

In this context of 'shared space', however, it is argued by some, to create disabling situations for people with a visual impairment, older people, and people with dementia.^[40] Attitudes towards shared space vary amongst the public, however.^[41]

The Department for Transport (DfT) guideline on shared spaces in urban street environments defines a shared space as:

"A street or place designed to improve pedestrian movement and comfort by reducing the dominance of motor vehicles and enabling all users to share the space rather than follow the clearly defined rules implied by more conventional designs.^[42]

This then needs to be reflected in the UK Disability Discrimination Act 2005^[43] which states that 'It is unlawful for a provider of services to discriminate against a disabled person'. This is taken from part 3 of the Act on discrimination in relation to goods, facilities and services. In addition, all of those involved in the planning, design and delivery of public realm schemes need to be aware of the requirements of the Equality Act 2010."^[44]

There are wider policy and practice movements with broader ambitions that just transport. Reviewing 'State of the Art' development of Design for All in the Scandinavian countries (Denmark, Norway, Sweden and Finland), researchers note that over the past ten years, that as a society they have come to realize that legislation is needed when it comes to pursuing an inclusive society, partly because changing governments pursue varying political priorities and agendas.^[45] Therefore, it may be helpful to introduce legislation in certain areas, although legislation alone does not automatically lead to Design for All products or solutions or even encourage companies, organisations etc. to implement Design for All as part of their strategy. It might instead lead to a situation based on the lowest common denominators. But political decisions and initiatives are essential for implementing Design for All.

In addition, Universal Design is the design and composition of an environment so that it can be accessed, understood and used to the greatest extent possible by all people, regardless of their age, size, ability or disability.^[46] Urban design comes from an architectural origin but in many ways strongly overlaps with inclusive design.

With a broader remit than shared space, and in terms of engagement and consultation, Rebernik et al (2019)^[47] describe a model for engagement in urban design, underpinned by ethnography. They note that this may be time-consuming and demands full dedication from city governments. Although well recognized as qualitative research methodology, ethnography is still an unusual approach in urban planning, design and governing practice. The fact that it is a highly time-consuming approach is its main weakness. Yet, the authors claim, it represents a highly applicable and firm complementary framework to serve urban planning and design researchers and practitioners in establishing closer connections with citizens, gaining their trust, enhancing their engagement and, finally, gaining an overall deeper understanding of their needs. Especially when it concerns understanding the (disabled) citizens' needs and how they use a space, what motivates them to use it and what prevents them from using it, the methodology proposed can go far beyond current practice, offering a way for governments to make informative and responsive decisions. It may be particularly helpful given the evidence provided in this Literature Review body of work as to weaknesses in engagement and consultation in the development and design of shared space.

Specifically, urban ethnography and the digital dimension are combined by encouraging the participants involved to engage with a few of selected mobile apps, such as EthnoAlly (http://cloud. mobility.deustotech.eu/ethnoally), Way-CyberParks (http:// cyberparks-project.eu/app), WheelMap (https://wheelmap.org) and Google Maps (https://www.google.com/maps), the most frequently used. The principles of digital ethnography are used as a modern approach to complement traditional ethnographic techniques, such as participant observation, interviews, focus groups and diary writing.

In further describing the broader landscape within which the specifics of this Literature Review are set there are a number of other issues which are important to highlight. These are that:

• It is often not possible to identify studies which just address 'high/busy streets' and inclusive street design and impaired mobility.
• Often studies mention 'shared space' in passing but address the experience of those with mobility impairments within a broad brush approach to mobility in the urban environment in general e.g. Sze, N., Chistiansen, K. 2017, Nillies, M., Kaparias, I. 2018.^[48], ^[49]
• Some important shared street studies are focused on residential areas including at least one published in 2015 addressing Scotland.^[50]
• Much of the literature focuses on walking for the non-disabled in shared use space in the context of 'reclaiming' space from motorised traffic.
• In terms of evaluation methods, there are a limited number of methods that consider disabled pedestrians as unique street users who have specific needs and require specific facilities^[51] although several are included as in scope for the Literature Review (the Indicators of Accessibility and Attractiveness of Pedestrian Environments developed by Moura, F., Cambra, P., Gonclalves, A. 2017, and the ethnographic approach proposed by Rebernik, N., et al 2019).
• There have been some contributions from transport professional institutions to debates regarding shared space. The Chartered Institution of Highways and Transportation made a recent contribution, albeit echoing some of the research findings reported in this Literature Review, and their report was particularly informed by case studies.^[52] It is of note that few of the schemes reviewed could point to a set of formal design objectives including headline objectives such as inclusive design and ease of movement, nor statutory duties such as the Equality Act 2010 or Traffic Management Act 2004.

14. Findings from the literature review

Assessment process

Thirty-eight studies were found to be in scope in this Literature Review. Given that seven of the studies were Reviews of the literature, the total number of individual studies referred to is greater than 38, and some single studies also summarised aspects of the literature in setting their own study in the wider context of the shared space literature. After searches had been undertaken to find studies and abstracts, these were checked to assess whether it was likely that they were in scope or out of scope. This involved reading the abstracts then accessing the full study to read if the abstract suggested that it might be in scope. Seventy studies were read in full.

A common procedure in identifying and examining a body of literature is to group studies under themes. For this Literature Review the themes are:

• Reviews (7).
• Single studies:
• Design and use (23).
• Non-visual impairments (2).
• Engagement and consultation (6).

Each theme is drawn on in detail in covering the range of topics identified in the Review in order to set out a cohesive narrative which seeks to draw together the evidence found.

Twenty studies were from the UK, four from elsewhere in Europe and 14 from beyond Europe. All studies are listed with their full citation in Appendix 2.

Overview

In the Commission for Architecture and the Built Environment's (CABE) view, streets that are designed to give all users more freedom in the way they use them are more civilised. They also, quite intentionally, remove the presumption that drivers have right of way among users because of the unpredictability that this creates. CABE note that research by Guide Dogs has examined the difficulties experienced by blind and partially sighted people and people with physical disabilities in independently navigating shared space street designs. It explored how to delineate 'safe space' if a traditional kerb was not used and more recently investigated a range of potential delineators used or proposed in UK shared space schemes. The research found that none of the current designs, in the forms tested, met the needs of both blind and partially sighted people and people with mobility impairments.

Hamilton-Baillie (2008) stated that shared space was an approach that was still in its infancy at that time, and there remained many barriers to overcome, observations to be made, evaluations to be conducted and experience to be gained. Questions remained as to what extent shared space can help resolve busier streets and intersections. He suggested that creativity and development is required to improve perceptions of safety and navigational aids for the visually impaired. The relationship between visual clues (such as apparent road widths, signs, kerbs and road markings) and driver behaviour were little understood. He noted that here remained unease and concern amongst some older citizens and amongst the blind and partially-sighted.

Similarly, Edquist and Corben, (2012) note that 'Shared space' is an approach to road design that is growing in popularity around the world. The idea is that instead of being segregated into their own sections of pavement, vehicles, pedestrians and cyclists are free to move through the space more or less at will, negotiating right of way with other road users via eye contact and social norms. In theory, the increased perceived risk of such a situation causes road users to slow down and be more aware and considerate of other road users. However, concerns have been raised that vulnerable pedestrians (particularly those with visual impairments) are not able to negotiate such spaces safely, and may be forced to avoid them, thus reducing their mobility. In addition, Norgate (2012) notes that the introduction of shared space has not addressed factors relating to the degree of unfamiliarity of space, which are issues for tourists/visitors who are visually impaired. This is a repeated concern among other studies so, for example, that Hautekier (2016) notes that faced with a non-familiar environment, to move independently is a big challenge and requires a high level of skills. That's why, in this situation, to capitalize on known planning or predictable elements is essential.

What is evident in the literature about the shared space concept is the shift towards recognising a street as a destination. Karndacharuk, Wilson, Dunn, (2014) note that while the term 'place making' within a public space, including streets, is widely used in the fields of architecture and urban design, recognising and operating a street as a place is not a straightforward process. Kaparios et al (2012) in their study focusing particularly on UK experience including Exhibition Road in Kensington, London, state that it has been concluded that there is a clear gap in research into the design of the layout of shared space streets. Moody and Melia (2014) suggest that there is no agreed definition of 'shared space'.^[533]

Edquist and Corben, (2012) also note that many concerns have been raised about the safety of shared spaces for vulnerable pedestrians. In particular, visually impaired pedestrians are not able to make eye contact with other road users, and if space negotiation in shared spaces is truly on this basis then these users are at an obvious disadvantage. Blind and visually impaired pedestrians use the kerb to navigate and determine where the 'safe' footpath is and where they are stepping into the space where vehicles may be present. Removal of kerbs (in level surface or 'shared surface' implementations of shared space) removes an important guidance tool and leaves these pedestrians unable to determine when they are in potential danger (Childs, Thomas, Sharp, & Tyler, 2010), as well as unable to respond to visual signals from other road users who may not realise they cannot be seen.

There is a 'believability gap' in that the evidence to support shared space does not necessarily convince its potential users that they will be safe and free from danger and harm, according to Imrie and Kumar (2011). They note that most local authorities they consulted were developing shared space schemes but not fully shared surfaces as features delineating pavements and roads are retained, though such delineations are not always able to be detected by people with sight loss. There is, they believed (2011), insufficient evidence to support some of the positive claims made for shared space projects, and some doubt about the relevance of accident statistics that claim to demonstrate their safety. It may be argued that shared space policy is one-dimensional insofar as it is focused on achieving technical design standards and does not address issues of behavioural change.

Thomas (2012) for Guide Dogs says that it is supportive of some of the ideas behind the 'shared space' concept, such as streets that are attractively designed and 'civilised', but it is very concerned by the creation of 'shared surfaces' for drivers, cyclists and pedestrians in the name of 'shared space'. Guide Dogs calls upon government to do the following.

a. Demonstrate its commitment to social inclusion, and to meet its disability equality duty in regulations, guidance, planning policy and decisions which impact on the pedestrian environment.

b. Ensure that professionals involved in the design, development and monitoring of streetscape and public space schemes take into account the requirements of disabled people.

c. Ensure that all parties consult with disability organisations at all stages in the process of developing streets and public places.

In similar vein, Bates (2016) notes that all UK guidance documents issued by the DfT emphasise that streetscape layouts must be fully inclusive and accessible to everyone, in accordance with the Public Sector Equality Duty. However, the shared space theory itself assumes that all pedestrians are fit and able to see where they are going, so the requirements of blind and vulnerable people who cannot share the roadway with vehicles is completely ignored. As a result, an increasing number of town centres are now being redeveloped in contravention of DfT guidance, even ignoring the sharing principles and the low traffic volumes and speeds expounded in the shared space theory which they purport to follow. Bates concludes that carriageways that are shared by both pedestrians and vehicles are of course welcome, so long as there are alternative safe routes for vulnerable pedestrians to use.

Interestingly, Jayakody et al (2018) state that the objective of inclusive design was identified as a measure to counter the main criticism of shared street streets, which is the difficulties encountered by older people and people with special needs. They report that even though the need was identified through the literature, a specific set of design factors could not be identified to achieve this objective due to the lack of literature covering this aspect in relation to shared space streets. Rather they identify key aspects from their own research.

Asadi-Shekari, et al (2019) have developed a Pedestrian Level of Service (PLOS) model to account for pedestrians with disabilities. Up until this work no PLOS models existed which took account of pedestrians with disabilities. Results show that the 'main facilities' have the highest association with inclusive pedestrian-friendly streets, followed by 'convenience facilities' and 'encouragement facilities'. Among the main facilities, a ramp has the highest association, followed by a curb ramp, sidewalk pavement, tactile pavement, driveway, width of sidewalk and bollard. Among convenience facilities, drinking fountains have the highest association, followed by rubbish bins, toilets and a lift. Among encouragement facilities, lighting has the highest association, followed by the landscape, trees and seating areas. The researchers PLOS model also shows that important encouragement facilities, such as lighting and seating areas, are inadequate on the street, while the main facilities and convenience facilities also need some improvement.

In some countries with little prior experience of shared space, but through learning from the evidence of those nations where shared space has been applied, there has been nervousness among visually impaired user group representative organisations. In Quebec, Canada, those representing the visually impaired, including the World Blind Union (based in Toronto), have been very reluctant to support the concept, especially when there is no clear demarcation between the sidewalk and the roadway (Gendron, 2018).

Design and use aspects

Norgate (2012) points out that given that one hallmark of the shared space schemes is 'level' surfaces, it has been acknowledged that: "level surfaces, especially in busier settings, can create significant problems for blind and partially sighted people who often use kerbs to define comfort space and to navigate by. Where a level surface is desirable therefore, it may be necessary to implement mitigating measures" (DfT), 2011: p. 40). The Local Transport Note (DfT, 2011) described forms of appropriate demarcation with flexibility 'dependent on circumstance', citing as examples tactile paving, bollards or other street furniture. Linked with this challenge is the differing needs of different users.

Hautekier (2016), citing the Royal College of Art Helen Hamlyn Center and Atkin, (2010), says that for a person with a visual residue, the colour contrast is the best source of information. For someone using a white cane for detection, auditory and tactile information predominate. As for the owner of a Guide Dog, the only source of tactile information comes from foot-tracking and feeling of descent and ascent transmitted by the harness of the dog when level changes. Havik et al (2015) observed whether, in a real-life situation, if and how a Shared-Space design influences the mobility performance of Visually Impaired people. Independence was only affected for the blind participants and not for the participants with low vision. The results of the study therefore do not imply a serious accessibility threat for the latter group. Within the blind group, however, it appeared to be in particular those using a guide dog who encountered most difficulties in the Shared-Space design: these were the participants showing the largest differences in independence Shared-Space locations and conventional locations. A limitation was the small number of guide dog users in the study (n = 5).

Edquist and Corben (2012) highlight that deaf and hearing impaired pedestrians may be similarly disadvantaged as visually impaired pedestrians in shared spaces as they are not able to hear cars coming up behind or beside them. Hearing impairments may be less visible than vision impairments, as hearing impaired pedestrians do not have obvious aids such as canes or guide dogs, so other road users are less likely to be aware of and compensate for these pedestrians' inability to hear.

Importantly, Gamache et al, (2019) notes that it was found in their Review that only a few of the articles considered more than one type of physical disability (motor, visual or hearing) (6 out of 40), meaning that most recommendations were made for individual impairments and not all users. Therefore, the recommendations found might in fact hinder some users by only being applicable/generalizable to one group. Few studies have addressed the same designs, determining how well they help, hinder or do not hinder (but do not help) persons with different impairments. The UCL researchers investigating minimum kerb height also added that, interestingly, it was generally true that delineators that worked for visually-impaired people were problematic for mobility-impaired people and vice versa (Childs et al, 2009).

General points

Havik et al (2012) report some positive consequences of the implementation of Shared Space for the visually impaired. These include low speed limits, spaciousness, and good lines of sight that accommodate a good overview of the situation. This latter point implies that visually impaired pedestrians are visible for other road users. Moreover, a good line of sight can also be helpful for those individuals who have some remaining vision.

An interesting finding from research in Quebec, Canada, regarding shared space has been that the vast majority of experts and officials are willing to introduce the zones alongside inclusion in the Highway Safety Code of a 'caution principle', according to Bruneau, Morency (2014). This considers that all users must pay attention to other users, especially the most vulnerable ones. Experts also believed that pedestrians and bicyclists should have priority over motorized vehicles. They agreed that shared space zones could be introduced, but inside a pilot-project frame only, since there is comprehensive fear around the concept, especially for pedestrians who are visually impaired.

However, in CABE's overall assessment (2008), if principles of inclusive design are considered from the outset of a project, and written into the design brief, then shared spaces can work for all users, including visually impaired people. Good shared space, for instance, will use design clues that still help the visually impaired. And 'safe zones', which are demarcated areas located near building lines, can help visually impaired people navigate shared spaces without fear.

Similarly, Jayakody et al (2018) review criticisms of shared streets and suggest that to mitigate issues related to shared spaces, more emphasis on design solutions are required. They suggest that the question will then be, "is it possible to plan and design the Shared Space Streets with due consideration on all the groups of users including children, older people, disable people, cyclists, young people, and families etc., without excluding any category of the society?" As such, 'inclusive design' can be considered as one of the main contributory factor for designing a successful Shared Street Space.

Specific design aspects are now discussed in more details.

Subjective (perceived) safety

Based on the subjective experiences of the visually impaired taking part in a field trial, Havik et al (2015) report that while the Shared-Space locations were evaluated more negatively than the conventional sites, the subjective safety was higher than expected. Although the conventional locations were rated higher than the Shared-Space locations, the safety comfort scores at both location types were at the high end of the scale,^[54] indicating that participants did not feel very anxious or unsafe at any of the locations. Their findings thus do not confirm the Shared-Space-related safety concerns found in a 2010 Guide Dogs for the Blind study.

Kaparias et al. (2012) found that pedestrians feel most comfortable sharing space in conditions which ensure their presence is clear to other road users – that is, conditions involving low vehicular traffic, high pedestrian traffic, good lighting and provision of pedestrian-only facilities. It was found that young men were the most comfortable sharing space, whereas people with disabilities and older people were more negative. Kaparias et al. (2012) produced similar findings for speed and volume of traffic, both significantly reducing the willingness of all pedestrians to share space with vehicles.

Referring to the MVA Consultancy work for the Department for Transport, across all the MVA sites, reported in Moody and Melia (2014), negative associations among mobility impaired users were found with traffic volumes, (as well as kerbs and 'colour contrast between carriageway and footway'). Across most of the sites, pedestrians gave way to vehicles more often than vice versa. Higher vehicle flows were associated with a lower propensity of drivers to give way, whereas higher pedestrian flows were associated with a higher propensity for vehicles to give way.

A study undertaken in Hereford, UK, used street accessibility audits followed by focus groups with three groups of pedestrians selected as especially vulnerable road users, including one comprised of blind or partially sighted participants, Hammond and Musselwhite (2013). Vulnerable pedestrians were no more likely to worry about safety on the street and findings from the focus groups with vulnerable groups suggested that in general people felt safety had improved in Widemarsh Street following the introduction of shared space. There was a feeling that vehicles still dominated the street, but in general people were not concerned by this, especially in terms of safety. Hence, there was a need to be aware of traffic, but people tended to feel traffic was far slower than before shared space was introduced.

Brown and Norgate (2019) report that evidence from five UK sites, testing shared space streets, suggested that blind and visually impaired participants' independent mobility was compromised in shared space. At times participants felt unsafe, disoriented and shocked, which is entirely at odds with the original aspirational intention behind shared space streets.

Edquist and Corben (2012) further note that it is important that the space does not look like a typical street and invite rapid vehicular movement. Design options to avoid this include limiting the area of straight road and/or visibility ahead for vehicles, pavement designs that suggest movement along pedestrian desire lines rather than vehicle desire lines, and the use of surfaces that are uncomfortable for vehicle occupants when driven over at high speeds (although these surfaces must be acceptable to mobility- and vision impaired pedestrians).

Kerbs and levels

Kerbs, no kerbs, and kerb height are assessed by different review authors. Norgate cites research reported by Thomas (2011) arising from the pedestrian accessibility movement and environmental laboratory (PAMELA) in University College London, UK, which showed that when both bullnose and chamfer kerbs, with heights between 20 mm and up to 120 mm, were tested with 36 participants, no-one failed to detect kerbs higher than 60 mm (see Childs et al, 2009 below). However, US data finds that among older adult pedestrian injuries, nearly a quarter of pedestrians injured by a fall reported that a kerb was involved, and that adults aged over 80 years were more likely than those aged 65– 69 years to have a fall involving a kerb (Naumann et al., 2011) reported in Norgate (2012). Moreover, Parkin and Smithies (2012) cautioned that the UCL controlled environment of the laboratory conditions should be combined with complementary field data, which accounts for the many and varied additional stimuli and navigational aids which go to make up the tool kit of resources used for navigation.

Norgate (2012) also reports on a Guide Dogs set of recommendations where it is stated that in pedestrianised zones and open spaces, reference points should be provided to assist blind and partially sighted people. Often this is achieved through different types of 'delineation'. Three particular approaches to achieving delineation are physical delineation (e.g. kerb, unless at a crossing point when it needs to be dropped), surface differentiation (e.g. tactile guidance paths) or visual contrast (e.g. a band and/or changes of colour) at surface level. Edquist and Corben (2012) note that it is important that all surfaces used are suitable for mobility-impaired pedestrians, and that safe edge space and the vehicle carriageway are delineated by tactile surfaces easily perceived by the visually impaired.

From field experiments in The Netherlands it was noted by Havik et al, (2012) that kerb edges or clearly detectable alternative demarcation between motorized traffic and pedestrians are needed. It is important that in the absence of traditional kerbs, alternative structures are put in place that can be detected by visually impaired persons, with either the foot or the long cane. Ideally, the alternative demarcation will also be detectable by guide dogs.

There was concern, from older people, wheelchair users and blind and partially sighted people, about the kerbs in the shared space design (Hammond and Musslewhite, 2013). The layout in Widemarsh Street, in Hereford, has a kerb in place that is much smaller than is found in a traditional layout, which also varies in height along the street. Vulnerable pedestrians across all the focus groups disliked this. People cited stories where they themselves, or others they knew, had tripped and fallen as a result of the kerb. It was this kerb height issue (50mm high) more than anything else that made people wary of the street and in some cases even put people off using the street altogether. The kerb edge problem was further compounded by poor contrast in material colour. The issue of the elimination of the kerb in shared space has long been cited as a problem for blind and partially sighted pedestrians who use a long-cane or a guide dog for navigation. However, findings from this research suggest blind and partially sighted people concluded that a kerb was not necessary but that a tactile edge could be used instead.

At the tactile level, Houtekier (2018)^[55] refers to detectability at the foot rather than using the cane. To do this, a difference in height of 5 mm allows good tactile detection while avoiding the risk of obstacles. Edquist and Corben (2012) note that it is important that all surfaces used are suitable for mobility-impaired pedestrians, and that safe edge space and the vehicle carriageway are delineated by tactile surfaces easily perceived by the visually impaired.

Safe edge space should be reserved for pedestrian usage by the use of kerbs with regular dropped crossing points or raised tables, or by the placement of street furniture, lighting, bollards, drainage channels, tactile delineators, trees and other vegetation say Edquist and Corben (2012). If the latter option is chosen, care must be taken that street furniture and other objects do not create an obstacle for pedestrians in wheelchairs and mobility scooters, and visually impaired pedestrians must be satisfied that they are able to detect the tactile delineators and safely navigate through the space.

In New Zealand three study areas that were transformed into shared spaces in the city centre of Auckland. Karndacharuk, Wilson, Dunn, 2013 reported that the design of the shared space considered the needs of the visually impaired, mobility impaired, and all other road users (including young and old) by placing a tactile delineator band 600 mm wide between the central shared zone and the marked accessible route (pedestrian- and mobility scooter-only zone). This accessible route on either side of the street was a minimum of 1.8 m wide. The two zones are demarcated by 600 mm-wide tactile delineator bands to warn the visually impaired about the possibility of moving vehicles. One conclusion was that shared spaces fundamentally creates a road environment in which there is enhanced priority for pedestrians (including the visually and mobility impaired) to safely move around and interact with the surrounding environment.

Sauer and Mastraglio (2017), drawing on US case studies and the literature, report that many case studies used kerbless design to update street geometry and meet the Americans with Disabilities Act (ADA) compliance. For example, levelling the street's surface may remove tripping hazards, which expands available travel paths for mobility-limited and vision-impaired users, as noted by a focus group of vulnerable road users who identified mobility benefits of improved navigation, better quality and more manoeuvrable paving treatment, and fewer areas for vehicles to obstruct pedestrian movement on kerbless streets.

Tyler (2017), discussing the planning and implementation for the shared space scheme in Exhibition Road , Kensington, London, notes that it was implemented with corduroy paving (which was one of the better performers in the PAMELA laboratory tests) used to distinguish between the part of the street where traffic was encouraged to pass and the rest of the street. Corduroy paving was both reasonably well detected by the visually-impaired group and reasonably possible to cross by the mobility-impaired group – but some members of each group failed the detection/mobility test, so it is not a fully successful solution.

Corduroy paving is one of the UK's standard tactile surfaces, but this application is not typical. Tyler notes that normally corduroy paving is set at the top and bottom of a stairway to alert visually-impaired people of the presence of the stairs. In Exhibition Road, it is laid along the whole length of the street, thus it can be approached at any angle.

Colour and tone

There is also the issue of colour and tones, and which the DfT local transport note (DfT, 2011 ref 19), pointed out that tonal (colour) contrast enables partially sighted users to perceive boundaries such as the edge of the carriageway. However, this report also acknowledges that complicated surface patterns can lead to disorientation. Jenness and Singer (2008), reported by Norgate (2012), studied 50 adults (aged 24–92 years) with some remaining useful vision but with limited visual acuity or visual field, and showed that detectable warning colours contrasting with pavement colour by a minimum luminance contrast of 60% could be seen from a distance of 244 m by around 92% of pedestrians under daylight conditions. The recommendation was that on dark pavements (e.g. asphalt) lighter coloured detectable warnings with a high reflectance index needed to be used to offer 'light-on-dark' contrast as opposed to 'dark-on-light' contrast.

Crossings

For crossing area, Rumboll Nyvig (2008) suggest that signal controlled crossings with audible signals are the preferred crossings for blind and partially sighted people. In a traditional street network where perhaps most street crossings are signal controlled, sufficient crossing opportunities may exist. But in a shared space environment it would also seem reasonable that blind and partially sighted people should be able to cross the street in places other than at junctions. Research in Leeds (UK) found that the experience of a number of visually impaired stakeholders and their advocates was that they felt that informal crossings were a good idea, yet expressed concern that in some cases they were being applied in areas where the vehicle flow was too high for them to function effectively Matthews, Hibberd, Speakman (2015). Regarding the informal 'crossing', in a field experiment in the UK, Brown and Norgate (2019) reported that participants expressed a need to identify a given point to cross through having access to distinctive markers or navigational cues. In this respect, under the current design the key feature of shared space was compromising the participant's independent mobility.

Houtekier (2018) says that crossings must be fully recognizable, for example using a direction mark: the beginning and the end of the zone are fully detectable with the cane or the foot, as well as the guidance line indicating the direction to take while replacing the border at the perpendicular of which the person with a visual disability is usually placed to make an online crossing. In addition, the crossing distance must be as short as possible (Houtekier (2018) citing Havik and Melis-Dankers, 2013).

Moody and Melia (2014) report on a case study which provided evidence from a high traffic volume shared space – Elwick Square zone, in Ashford. The ring road accommodates two-way vehicle movements and is subject to a 20 mph speed limit. There is very little sign of segregation between modes, with all users occupying a largely unmarked level surface with no vegetation or street furniture (apart from lamp standards) in the main part of the square. The square also accommodates traffic flows of approximately 11,000 movements per day and up to 850 movements per hour, presenting an opportunity to analyse the use of shared space in an area of high traffic flow.

Video recordings found that most pedestrians tended to use the informal 'courtesy crossings', lengthening their route and diverting their desire line away from the natural continuation of the carriageway at the centre of the square. In 72% of the conflicting movements, the pedestrian initially gave way to the vehicle. In 20% of instances the vehicle subsequently gave way, leaving 52% of conflicting movements where the pedestrian waited at the edge of a zone, until the traffic had moved on. Although most pedestrians treated the courtesy crossings like zebra crossings, most drivers did not treat them in this way, initially giving way in only 37% of conflicting movements with a pedestrian.

For those with non-visual impairments there were also concerns regarding crossings. This is addressed in that section (below).

Entering and exiting shared space

Entering and exiting a shared space area needs some consideration. Havik et al (2012) note that the fact that an individual is entering an area where different rules apply for vehicular traffic and social interaction can be crucial to know. Even though visually impaired persons do not have to behave differently themselves, it can be helpful to know that they are no longer walking on a traditional kerb and that other people will (supposedly) pay more attention to them. Parkin and Smithies (2012) report that there is evidence supporting the views of Methorst et al. (Methorst, R., Gerlach, J., Boenke, D. & Leven, J. (2007) who suggest that the boundaries of the Shared Space should be clearly marked to drivers. No other studies addressed this aspect.

Road casualties and speed

In terms of evidence for the efficacy of the shared space schemes, Norgate (2102) reports that whereas some studies have sought and found evidence for reductions in road casualties, others have focused on perceptions of users towards pedestrian comfort and driver willingness to reduce road speed.

Karndacharuk, Wilson, Dunn, (2014) reported on the Elliott Street shared space in New Zealand and vehicle speeds. This incorporates a safe zone for vulnerable users, a designated space for temporary trading activities and legal signs at the entry and exit points. Research revealed the importance of active land-use frontage, the number of pedestrians and the design that encourages pedestrian and vehicle interactions in the space. These factors contributed to the reduction in vehicular operating speeds, which were 16 and 21 km/h for the mean and 85th percentile speeds, respectively. Based on the design features and the vehicular speed outcomes, the scheme most similar to Elliott Street in New Zealand is New Road in Brighton in the UK. Both schemes achieved a similar result of reducing vehicular dominance in speed and volume as well as utilising the street space as a place. Moreover, perception surveys of the New Road scheme indicated an overwhelming support from the general public and businesses. It is noted below in the Engagement and Consultation section that the Brighton scheme was adapted after engagement with visually impaired users.

With regards to collision data, Edquist and Corben, (2012) found data for eighteen road spaces using Shared Space principles to a greater or lesser extent (mostly in the Netherlands or Britain). The limited data available so far suggests that crash rates are not consistently either higher or lower than comparable traditional environments. Many of the crash evaluations suffer from problems such as limited data collection times, the lack of a comparison site or control data to account for wider trends, failure to collect exposure data, and failure to collect injury data for collisions not involving vehicles (i.e. pedestrian-cyclist collisions, single-cyclist and pedestrian fall incidents). These limitations constrain the conclusions that can be drawn about the effects of Shared Spaces on safety.

Havik et al (2015) reported that in their study of locations in the Netherlands, although shared-space design does not necessarily require smooth pavement gradients, these are often implemented. Without detectable tactile demarcation between the pavement and the street, blind pedestrians unlike sighted pedestrians cannot make a voluntary decision to leave the pavement and walk on the street. The absence of detectable demarcation in many shared spaces can therefore lead to the highly undesirable situation of blind pedestrians walking in the middle of the street without knowing it and possibly without being able to react adequately to approaching vehicles. These situations occurred 28 times in the Shared-Space locations (vs eight times in the conventional locations), representing nearly 25% of all interventions. This number of potentially dangerous situations is considerable and represents a major concern for the accessibility of Shared Spaces. There was not sufficient data to be able to report on traffic casualties and mobility impaired people in comparison to the pre-shared space street.

Matthews, Hibberd, Speakman (2015) reported on a 2010 survey of 500 visually impaired people (TNS-BMRB, 2010).^[56] In terms of accident rate, 7% of those who had used a shared surface area reported that they had been involved in an accident, with a further 42% experiencing a near-miss. Worryingly, 81% felt that their independent mobility would be negatively affected by the introduction of shared surfaces. In fact, this reflects a more general concern amongst their stakeholders that the relatively low number of reported incidents between visually impaired individuals perhaps disguises the underlying impact of such areas on the mobility of these individuals. Of the 61% of respondents who had experienced a shared surface environment, 44% reported actively seeking alternative routes to avoid a shared space area, with a further 18% being reluctant to use the area. This is also reported by Smithies (2015). By contrast, Sauer and Mastaglio (2017) note that of the US case studies they reviewed, none reported injury-related pedestrian crashes. Vehicle speeds posted for shared or kerbless streets were usually 15 to 20 mph in their case studies.

An interesting footnote to this issue comes from Karndacharak, Wilson, Dunn (2016) who explored the safety of shared space users in city centre streets in Aukland, New Zealand. They interviewed experts and reported that the responses included that:

"There will inevitably be an incident in a shared space, but (we) need to remember that such incidents happen in all streets. The (shared) spaces were not implemented for safety reasons, but were designed to be no less safe than a conventional street."

Another expert touched upon a balancing act in designing a shared space from a road safety perspective as follows:

"Safety is most important but you cannot have a totally risk-averse mentality when designing these spaces – very important to differentiate the perception of a lack of safety with an actual lack of safety".

Safe Areas within shared space

Parkin and Smithies (2012) suggest that there should be safe areas within shared space which remain reserved for pedestrians. This is reported by Karndcharuk, Wilson, Dunn, (2014) as a call from visually impaired users to include a 'safe space' area free from sharing with vehicles, and also by Guide Dogs (Thomas 2008) and as noted by Norgate (2012) reporting on another report from Guide Dogs in 2011. Safe space is also a recommendation made by Smithies (2015).

Havik et al, (2012), from a Dutch perspective, with a quarter of all trips in The Netherlands being made by bicycle, ask: How to deal with cyclists in the pedestrian area? They report that in The Netherlands the introduction of 'safe zones', 'safe spaces' or 'comfort spaces' for pedestrians has also been recommended to avoid this potential problem. These 'safe spaces' are described as zones that are strictly reserved for pedestrians; although not delineated by a traditional kerb, they should be clearly detectable by visually impaired users. As the Rambol Nyvig report for Guide Dogs (2008) states, the inclusion of safe spaces would be considered the equivalent of the footway and would not prevent motorists, cyclists and pedestrians from sharing the larger part of the street.

Car parking space

Designated parking places or a no-parking zone is raised in Dutch research in shared space areas by Havik et al, (2012). A clear parking policy with either carefully designated parking places or a no-parking zone should be part of the shared space design. Part of the case against car parking in shared space is that a clear view across the area by the sighted (including drivers and cycle users) and partially sighted can, however, be disturbed by parked cars. Edquist and Corben (2012) recommend that Disabled Parking should be available close enough (without defining this) to allow access to destinations within the shared space area for pedestrians with limited mobility.

Assessment tools for shared space

In order to assist policy makers, designers and architects in developing accessible shared space areas, researchers Havik et al (2015) developed a shared-space Guide. This guide is freely accessible through the internet (www.visio.org or http://www.eccolo.nl/shared-space). The researchers add that it provides practical information with respect to designing shared space areas that are also accessible by people with a visual impairment. Furthermore, it contains a checklist of important issues during the design process.

Almeida (2016) presents the development and piloting of SeGAPe (Seniors' Group Assessment of Pedestrian Environment), a participatory instrument to evaluate and rate the quality of streets for walking from the viewpoint of older adults in a Portuguese urban context. SeGAPe was developed following an extensive review of literature on walkability, and instruments and methods to conduct street audits.

The Community Street Review, commissioned by New Zealand governmental agencies and developed by transportation and health experts, was identified as a useful template "where a community street audit and a rating system are combined," creating an easy-to-use "nationally recognized standard for measuring walkability using peoples' perceptions". The Street Segment form comprises a total of 27 questions, and the Crossing form comprises a total of 23 questions. Together these covered overall categories of: Walkability, Efficiency, Obstacles, Safety from Traffic, Safety from Falling, Comfort and Effort, Orientation, Safety from Crime, Destinations and Pleasantness (Almeida, 2016).

Regarding usability, in terms of inclusive design, it should be noted, however, that as the pilot study did not involve participants with severe mobility or sensory limitations or significant frailty, SeGAPe's usability remains to be verified with more impaired participants.

Moura, Cambra, Gonclalves (2017) present a participatory walkability assessment framework for distinct pedestrian groups, which was named IAAPE (Indicators of Accessibility and Attractiveness of Pedestrian Environments) and that aims to support urban planning and design for more walkable environments. Among the many output possibilities from the IAAPE tool, the researchers extracted those aiming to illustrate the usefulness of the assessment framework for the cases of senior pedestrians and persons with mobility impairments, when compared to fitter adults. Cane use, wheelchair use, and baby buggy use were three impairments used.

The evaluation of individual key-concerns is aggregated into single walkability scores that are differently composed and weighed depending on the pedestrian group and trip motive. A main conclusion here is that improving in the pavement quality is important for Seniors, in order to improve the overall walkability in the area (although also important for impaired mobility pedestrians), whereas making the walking infrastructure more accessible is paramount for impaired mobility pedestrians.

Autistic Spectrum Disorder

Cowan et al (2018) states that navigating a shared zone relies heavily on social interaction, particularly eye contact. Eye contact is also important in road crossing situations as it allows for the quick and efficient detection of hazards which is important to maintaining pedestrian safety. Given the environmental demands of shared zones, it could be assumed that the social difficulties associated with Autism Spectrum Disorder (ASD) could result in difficulty for individuals with ASD in communicating their intent and perceiving and interpreting the intent of other road users in shared zones.

Earl et al (2018) report that participants with cognitive impairment are failing to comprehensively process and assign importance to visual stimuli when in the shared zone. This study also found that individuals with Autistic Spectrum Disorder (ASD) had shorter fixation durations, in both locations, and on traffic relevant and non-traffic relevant objects. This could be due to atypical visual perception or hypersensitivity to environmental stimuli, which are both characteristics for individuals with ASD. These findings contribute to the paucity of research examining shared zones (streets), which has allowed for suitable recommendations and environmental adaptations to be suggested for current and future planning of shared zones.

Earl et al (2018) add that the current literature suggests that the core impairments of ASD, particularly in the area of social processing may lead those with ASD to experience difficulty in road crossing at uncontrolled crossing points such as a shared zone (street). An individual with ASD may have difficultly or fail to prioritise the eye contact of other individuals. Furthermore, they may have difficulty following and interpreting the gaze of another person. For people with ASD, differences in patterns of eye contact in a shared zone may lead to missing or misinterpreting the gaze cues of other users, in particular drivers, or failing to accurately convey their own intentions when crossing traffic placing them at increased risk of collision.

Engagement and Consultation

Norgate (2012) reported on a UK initiative, the 'Streets ahead' campaign by Guide Dogs UK. This advocated the need for inclusive principles to underpin the design of both new and existing streetscapes. In addition, this was to be achieved alongside moves to equip blind and partially sighted people with the tools to engage in communication with local authorities, engineers, architects and town planners, so as to ensure consultations are effective in taking their needs into account. Edquist and Corben (2012) noted that high levels of consultation with local stakeholders are vital, particularly with vulnerable groups. It is important that this consultation is an ongoing process throughout the design, construction and early operation phases of any implementation, not just a token community meeting once the design has already been created. Shared spaces are not just another traffic countermeasure; they are a new way of thinking about streets. Similarly, Imrie (2013) says that stakeholder engagement plays a pivotal role in the development of shared space. He notes that the Department for Transport (2011, p. 22)^[57] says that schemes are more likely to be successful if engagement is inclusive, involving a wide cross-section of the community.

Previous survey reports by Thomas (2008) highlight the 'before and after' surveys of shared space in New Road, Brighton, UK, which aired concerns by blind and partially sighted users that shared space would reduce independence, be more difficult to navigate and negatively affect their confidence. As noted above, the local council was responsive to this feedback and subsequently engaged in initiatives that sought to introduce the concept of a 'safe space' in which there was spatial segregation of vehicles from pedestrians.

Through Imrie and Kumar's (2011) survey of local authorities in England there was little evidence of involvement of people with sight loss at strategic levels of policy making relating to the determination of the broad principles and the scope of shared space policy. Rather, people with sight loss become aware of shared space schemes at the later stages of the policy process and are usually drawn into consultation only prior to the implementation of programmes. The involvement of Guide Dogs in commenting on specific shared space policies appears to have been influential in changing aspects of design detail and outcomes. There was evidence of changes to details of shared space policy and practice as a result of consultation (note above New Road, Brighton). Such changes were, primarily, at operational rather than strategic levels, and related to small-scale, specific details of design. Moreover, Imrie and Kumar (2011) reported that there was little evidence of policy officers, councillors, or consultees disseminating the outcomes of consultation to people with sight loss throughout the local boroughs.

Parkin and Smithies (2012) report that visually impaired people use a rich catalogue of techniques for navigating and that these techniques need to be widely known and understood by designers. Such an understanding, coupled with creativity, will allow designers to construct spaces which are not only interesting to 'look at', but also rich in their offering of attributes which allow for easy navigation. This requires engagement.

Matthews, Hibberd, Speakman (2015) note that the misinterpretation by designers that the implementation of a shared space requires a shared surface. In particular the removal of kerbs results in the absence of a well-established and crucial means for visually impaired people to orient themselves and navigate, in addition to aiding in the identification of a crossing point (e.g. a dropped kerb). They state that there is a misunderstanding of the capabilities of the visually impaired pedestrian within shared spaces. For example, stakeholders mentioned apparent assumptions that all visually impaired pedestrians had sufficient residual sight to identify that they were in a shared space area, can navigate without kerb delineation of the roadway, and are able to detect vehicle presence, vehicle movement, and their desired crossing start and end points. There was, according to mobility-impaired users, but notably from visually impaired users, an over-reliance on eye contact to manage pedestrian-vehicle interactions in shared space.

Tyler (2017) discussed proposed design for a scheme was to create a pleasant environment for people in the street by eliminating kerbs and vertical infrastructure and removing the overt separation between traffic and pedestrians. The issue brought to the attention of the local authority was that visually-impaired people would find it very difficult to have confidence in the safety of the street, as they would not know where the traffic would be. Researchers in the PAMELA facility were asked to test possible methods for differentiating zones where traffic might be and zones where traffic would not be present, where these methods did not involve a vertical obstruction to the vista of an open space (see Childs et al, 2009). Accordingly, 24 different designs of tactile paving were installed in the laboratory and tested by two groups of people: visually-impaired people and mobility-impaired people. The laboratory was set up with a set of delineators arranged so that participants could approach them at right angles or at an angle, and they were instructed to stop when they believed they had detected the change in surface.

In Quebec, Canada, the introduction of shared space brought about a collaborative research approach which played a key role in bringing together stakeholders from different backgrounds to address a clearly defined issue lacking in proven solutions (Gendron, 2018). In the end, this collaborative research exercise helped all participants gain new knowledge and a deeper understanding of three key aspects of the universal accessibility of shared streets: impacts on professional practices; existing sustainable mobility issues, including issues relating to the pedestrian dimension of shared streets; and impacts of design decisions on the mobility of persons with functional limitations.

In Auckland, New Zealand, in catering for the visually impaired, the shared space design team consulted with the Royal New Zealand Foundation of the Blind (Kardacharak, Wilson, Dunn, 2016). They were originally concerned about "loss of kerbs and straying onto the carriageway". Extensive consultation on pavement materiality and design prototypes, especially the 'accessibility zone' with tactile delineators, led to the satisfaction of the disability user groups, the researchers report.

Beyond the remit of shared streets, Lowe et al (2015)+^[58] address engagement and consultation with regards to the expansion of the Metrolink light rail system in 2008. Transport for Greater Manchester (TfGM) established a consultative group entitled the Disability Design Reference Group (DDRG) at the outset to support this major civil engineering project. This step was also a means of helping TfGM to comply with the requirements of the Equality Act (2010). TfGM established the DDRG, which comprises disabled people with a range of impairments, ethnic backgrounds and ages from across the Greater Manchester region. Lowe et al (2015) note that the DDRG enabled TfGM to discharge its legal and ethical duties by providing a means of influencing the next generation of inclusive design by anticipating and proposing practical solutions in relation to gaps in existing accessibility guidance and standards.

Findings

There is an array of findings from the literature. At the general level there needs to be greater recognition of the needs of all users, including people with sight loss (Imrie and Kumar, 2011; Smithies, 2015). The views and feelings of vision-impaired people are not a significant part of the high level policy-making process (Imrie, 2013). There is a need for clear guidelines on how to prevent the identified issues from occurring in newly designed shared spaces and how to improve existing shared-space schemes (Havik et al, 2015; Audrey, Leonards, Damens, 2017). This is supported by Imrie and Kumar (2011) who say that more detailed guidance is required on the development and implementation of shared space.

The seeming lack of consistent standards provides designers with a blank canvas when creating shared-use areas, often meaning that the needs of vulnerable road users, including the blind and visually impaired, are forgotten among the aesthetic details. Shared spaces should not be a uniform material, but distinct safe areas and boundaries within the shared space should be present to create an environment that is easily identifiable and understandable to the blind and visually impaired. A consistent approach to designing for the blind and visually impaired should be introduced. This could be achieved by establishing national standards and specifications with appropriate enforcements Smithies, (2015).

Communication emerges as a challenge to designers and implementers. Communication should be improved e.g. between guide-dog trainers and highway authorities. Authorities should consult with blind and visually impaired organisations, seeking their opinions before the detailed design stage (Smithies, 2015). As such highway engineers should be provided with training opportunities to develop their skills in designing for vulnerable road users (Smithies, 2015).

More broadly, and a challenge, is an expectation of general enjoyment of greater pedestrian space for one group comes at the price of a limited expectation of these benefits for another group. This suggests that even within the broad category of those with impaired mobilities there is not only an accessibility issue, but also a challenge to the equity of the scheme – which would strike at one of the three pillars of sustainability. How would equity be delivered? (Tyler, 2017).

"The 'evidence gaps' need to be addressed, particularly in relation to personal safety issues" (Imrie and Kumar, 2011).

Literature review conclusions

1. An overall issue is that shared space is contested with claims that disabled users are ignored (Thomas, 2008; Imrie and Kumar, 2011; Imrie, 2013). However, there are studies providing examples of how accessible design can be better achieved through greater efforts at consultation and engagement, especially with groups representing the physically, sensory, and mentally impaired users (Jayakody et al, 2018; Kardacharak, Wilson, Dunn, 2016; Gendron, 2018).

2. There is no agreed definition of 'shared space' (Imrie and Kumar, 2011; Moody and Melia, 2014) and this is reflected by an inconsistent approach to shared-space design (Smithies, 2015). This may have been the result of the extension of the shared space concept beyond implementation in low flow residential areas, to its use in busy urban areas and shopping streets and which has not been thought through (Matthews, Hibberd, Speakman, 2015)

3. Kaparios et al (2012) conclude that there is a clear gap in research into the design of the layout of shared space streets. There is a need for clear guidelines in newly designed shared spaces and how to improve existing shared-space schemes (Havik et al, 2015; Audrey, Leonards, Damens, 2017). More detailed guidance is required on the development and implementation of shared space (Imrie and Kumar, 2011).

4. There is a limited highly quality (robust) literature on inclusive design aspects from the perspective of those with mobility and or sensory impairments. In the literature it has been noted that quality scores of most of the articles were low. This might indicate limitations in the methods used and their lack of standardization (Gamache et al, 2019).

5. There is a paucity of research-based knowledge about the mobility situation of persons with cognitive functional limitations (Gamache et al, 2019), and this is reflected in previous broader transport research.

6. There is evidence that measures which may benefit some users such as visually impaired can disadvantage other users e.g. tactile blisters by disturbing the gait of older pedestrians near to crossings. The same is likely of other measures such as the risks that curbs can for some users be a trip hazard (Naumann et al., 2011 in Norgate, 2012). Only a few of the articles considered more than one type of physical disability (motor, visual or hearing) (6 out of 40), meaning that most recommendations were made for individual impairments and not all users (Gamache et al, 2019).

7. There is mixed evidence as to whether the introduction of shared use on high streets and busy streets had increased accidents but there are a significant number of studies reporting that mobility impaired users were avoiding these areas, noting that most reports were from the visually impaired e.g. Matthews, Hibberd, Speakman (2015), Tyler, (2017).

8. While the debate about kerb edges is still contested by some there appears to be a consensus that if not kerb edges than clearly detectable alternative demarcation between motorized traffic and pedestrians are needed (e.g. Havik et al, 2012; Hammond and Musselwhite, 2013).

9. Highway engineers should be provided with training opportunities to develop their skills in designing for vulnerable road users (Smithies, 2015).

10. Highway authorities should consult with a range of mobility impaired organisations, seeking their opinions before the detailed design stage of any proposed shared use scheme is taken forward (Smithies, 2015). It is important, therefore, that this consultation is an ongoing process throughout the design, construction and early operation phases of any implementation (Edquist and Corben, 2012).

11. 'Safe space' areas that are strictly reserved for pedestrians appears to be a well-supported compromise as a design solution and an example of a feature which gives mobility impaired users confidence to engage and move through the shared space Rombol Nyvig, 2008; Havik et al, 2012; Norgate, 2012; Parkin and Smithies, 2012; Karndacharuk, Wilson, Dunn, 2014).

Limitations

One limiting factor in this Literature Review is that the five search engines selected and agreed produced a limited find in terms of included studies and this raises the question as to the value of investing in a more exhaustive search. A more exhaustive search might also involve expanding the inclusion criteria as well as search terms. Secondly, despite expanding on the search terms significantly, no search strategy is likely to find all studies and especially given the time resource allocated. However, it should be noted that after additional search terms were included the new searches themselves found very few new studies but did largely find again studies already captured using the smaller original list of search terms. This give some confidence that the searches were reasonably effective in locating studies.

In addition, there is a real issue of external validity to consider, i.e. the extent to which the results of a study can be generalized to and across other situations, people, stimuli, and times. This includes evidence from other countries and cultures where, for example, mores and norms of behaviour are different. A question which then arises is: to what extent can 'successful interventions' from such locations be imported to a UK environment and culture? (i.e. external validity). Lastly, focusing only on studies reporting in the English language is clearly another limitation albeit that the risks associated with external validity may be consequently reduced.

Annex A - Included studies – summary points

No.	Authors and year	Summary points	Location
	Reviews
1	CABE, 2008.	If principles of inclusive design are considered from the outset of a project, and written into the design brief, then shared spaces can work for all users, including visually impaired people. Good shared space, for instance, will use design clues that still help the visually impaired. And 'safe zones', which are demarcated areas located near building lines, can help visually impaired people navigate shared spaces without fear.	UK
2	Edquist, J., Corben, B. 2012.	The project aimed to review collision data from existing Shared Space implementations around the world. Where possible, information was also gathered on other important factors such as perceived safety, accessibility and amenity for pedestrians, cyclists and vehicles. Collision data was available for eighteen road spaces using Shared Space principles to a greater or lesser extent (mostly in the Netherlands or Britain). The limited data available so far suggest that crash rates are not consistently either higher or lower than comparable traditional environments.	Europe
3	Norgate, S. 2012.	Overall, it is apparent from the content of three key sources (DfT, 2011; Guide Dogs UK, 2012; WHO, 2007) that their statements are not entirely aligned. In particular, the Guide Dogs UK 'Streets ahead' campaign has pulled the pedestrian into the foreground and has devised a number of principles and interventions which can promote the safe and independent mobility of blind and partially sighted pedestrians.	UK
4	Karndacharuk, A., Wilson, D. J., Dunn, R. 2014.	This comparative review highlights the importance of achieving a low-speed environment via design with a provision of safe zones for the visually impaired, space reallocation for pedestrians and street furniture for the 'staying' activity to enable a shared street to perform multi-functions, especially to create a sense of place.	New Zealand
5	Houtekier, C. 2016.	The review aims to answer three questions: 1) How are the streets be a barrier to travel people with visual impairment? 2) From the point of view of the person with a visual impairment, what skills in orientation and mobility are identified in the writings as compromised or transformed into a shared street? 3) Are there solutions of replacement to respond to the loss of benchmarks and accessibility what can these changes represent? The assertions from the literature are intended to supply answers in a way that categorises on the one hand, issues related to orientation and mobility and development and, on the other hand, the possible solutions according to components of a shared street and the concerns of planning and safety specialists in universal accessibility.	Canada
6	Asadi-Shekari, Z., et al 2019.	The researchers' study sought to develop innovative Pedestrian Level of Service models, which explain and evaluate inclusive streets for walking, focusing on universal micro-level design factors for a wide range of street users, in particular disabled people, while considering pedestrian perceptions of their environment.	Malaysia
7	Gamache, S. et al, 2019.	In this Review, 41 articles were reviewed. The scope of the pedestrian infrastructures discussed in the articles was large. It was found that only a few of the articles considered more than one type of physical disability (motor, visual or hearing) (6), meaning that most recommendations were made for individual impairments and not all users. Therefore, the recommendations found might in fact hinder some users by only being applicable/generalizable to one group. Additionally, individuals with intellectual, psychological and cognitive impairments should also be considered in future research for a more global approach of public health. Finally, the quality scores of most of the articles were low. This might indicate limitations in the methods used and their lack of standardization.	Canada
	Single studies: Design and us
8	Ramboll Nyvig for Guide Dogs for the Blind, 2008.	Drawing on international experience including from Denmark the project identified four potential design approaches to be tested: The kerb is reintroduced in the street design in a form that is compatible with the shared space concept. Instead of a kerb, a textured area is introduced between the shared space and the safe space. A route indicated by tactile paving – the guidance path surface – is provided. Instead of a division between the 2 "spaces", other measures are applied to guide blind and visually impaired pedestrians - e.g. a central delineator. In addition, attention is given to the need for signed or non-signalled crossings in shared space areas.	UK
9	Hamilton Baillie, 2008	Draws on case studies e.g. Norrköping, Sweden, there remains unease and concern amongst some older citizens and amongst the blind and partially-sighted. Whatever its shortcomings, as an example of shared space Skvallertorget in Norrköping demonstrates that traffic signals, road markings, kerbs, crossings and barriers are not essential elements that have to be tolerated as an unfortunate necessity for the maintenance of safety and efficiency of movement. A distinctive, coherent and integrated piece of public space can successfully serve the needs of passing traffic without such disruptive, expensive and disfiguring components. Shared space is an approach that is still in its infancy, and there remain many barriers to overcome, observations to be made, evaluations to be conducted and experience to be gained. Questions remain as to what extent shared space can help resolve busier streets and intersections. Creativity and development is required to improve perceptions of safety and navigational aids for the visually impaired. The relationship between visual clues (such as apparent road widths, signs, kerbs and road markings) and driver behaviour remains little understood.	UK
10	Thomas, C. 2008.	Guide Dogs believes that 'shared surfaces', without clearly identified pedestrian footways and controlled crossings, pose a threat to all vulnerable road users, including those with physical, sensory or cognitive impairments. The statement calls upon government to do the following. Demonstrate its commitment to social inclusion, and to meet its disability equality duty in regulations, guidance, planning policy and decisions which impact on the pedestrian environment. Ensure that professionals involved in the design, development and monitoring of streetscape and public space schemes take into account the requirements of disabled people. Ensure that all parties consult with disability organisations at all stages in the process of developing streets and public places.	UK
11	Childs, C., et al 2009.	Since some local authorities want to reduce the kerb height from the traditional 120mm and 30mm is too low, Guide Dogs asked UCL's Accessibility Research Group to run tests to determine what kerb height could be reliably detected by blind and partially sighted people. The experiments took place in May and June 2009 at the University College London's Pedestrian Accessibility Movement and Environment Laboratory (PAMELA). For confidence that a kerb is detectable by blind and partially sighted people, it is recommended to install a kerb of 60mm or greater.	UK
12	Right of Way and Road Safety: Inclusive Mobility, 2010.	Research demonstrates the access needs of pedestrians with disabilities and highlights the efficacy of pedestrian safety audits to implement necessary improvements. The study proposes amendments/ additions to the existing standards and guidelines of regulatory authorities.	India
13	Havik, E., Melis-Dankers, B., Steyvers, F., Kooijman, A. 2012.	An aim of the inventory was to assess the consequences that a Shared-Space street layout can have for the accessibility for visually impaired persons. Assessment of compatibility with the accessibility guidelines showed that none of the locations met all of the selected accessibility guidelines relevant for visually impaired persons. Guidelines that were violated at nearly all locations included a clearly marked and obstacle-free walking route, sufficient route guidance, and tactile warnings. Moreover, the expert group judged the level of hindrance the registered characteristics could cause to the orientation and independent mobility of visually impaired persons and their feeling of safety when walking in the environment. Based on these judgements, and on the observed frequency of the characteristics, the authors were able to identify several accessibility problems for visually impaired persons that can result from the implementation of a Shared-Space design as found in the Netherlands.	Netherlands
14	Parkin, J., Smithies, N. 2012.	Blind and visually impaired people use many tactile and sensory clues to help them locate themselves and navigate; the value of tactile paving will depend on the extent to which it adds value relative to the other navigation clues used by blind and partially sighted people.	UK
15	Kaparias, I. et al 2012.	It has been discovered that a certain discomfort towards shared space exists amongst the elderly and disabled road users, as these seem to feel an increased threat from vehicles in such environments.	UK
16	Karndacharuk, A., Wilson, D., Dunn, R. 2013.	A pedestrian performance analysis of three study areas that were transformed into shared spaces in the city centre of Auckland was presented. The design of the shared space considered the needs of the visually impaired, mobility impaired, and all other road users (including young and old) by placing a tactile delineator band 600 mm wide between the central shared zone and the marked accessible route (pedestrian- and scooter-only zone). This accessible route on either side of the street was a minimum of 1.8 m wide. The two zones are demarcated by 600 mm-wide tactile delineator bands to warn the visually impaired about the possibility of moving vehicles.	New Zealand
17	Bruneau, J., Morency, C. 2014.	Experts believed that pedestrians and bicyclists should have priority over motorized vehicles. They agreed that Zones could be introduced, but inside a pilot-project frame only, since there is comprehensive fear around the concept, especially for pedestrians visually impaired.	Canada
18	Moody, S., Melia, S. 2014.	For highway engineers and transport planners who need to take decisions on shared space, it would seem that reducing both the speed and volume of traffic is key to achieving pedestrian benefits.	UK
19	Havik, E. et al, 2015.	Within the blind group it appeared to be in particular those using a guide dog who encountered most difficulties in the Shared-Space design; these were the participants showing the largest differences in independence (percentage of routes without interventions) between Shared-Space locations and conventional locations.	Netherlands
20	Matthews, B., Hibberd, D., Speakman, K. 2015.	Whilst there appears to be a reasonable degree of consensus regarding the aims of shared space, the ways in which it is implemented and the implications for visually impaired people, and other vulnerable road users, clearly need to be revisited. Perhaps a more collaborative approach, fostering user-led, co-designed accessible streetscapes offers the best hope of moving toward resolving these conflicts and, in doing so, speeding up the transition to street accessibility for all.	UK
21	Smithies, N. 2015.	The author noted that the lack of consistent standards provides designers with a blank canvas when creating shared-use areas, often meaning that the needs of vulnerable road users, including the blind and visually impaired, are forgotten among the aesthetic details.	UK
22	Almeida, M. 2016.	The Seniors' Group Assessment of Pedestrian Environment tool aims to be a practical, systematic method to assist in conducting a structured assessment of walkability conditions and improvement opportunities, acknowledging older citizens' experience and directly engaging them in the planning process of age-friendly urban public spaces. Limited testing with impaired users.	New Zealand
23	Bates, D. 2016.	There is often no attempt to discriminate between people who are totally blind and those who have some degree of usable sight. Official guidance given to UK streetscape designers by the Department for Transport emphasises the value of colour contrast to help visually impaired people, and this general emphasis may have helped to create the occasional but mistaken impression that blindness is synonymous with visual impairment.	UK
24	Earl, R. et al. 2016.	Shared zones are claimed to increase driver awareness and safety and reduce congestion, but the implications on participation and safety for those with visual and cognitive impairments is yet to be extensively explored.	Australia
25	Moura, F., Cambra, P., Gonclalves, A. 2017.	Among the many output possibilities from the IAAPE tool, the researchers extracted those aiming to illustrate the usefulness of the assessment framework for the cases of senior pedestrians and persons with mobility impairments, when compared to fitter adults. Cane use, wheelchair use, and baby buggy use were three impairments used.	Portugal
26	Sauer, C., Mastaglio, B. 2017.	Many case studies used curbless design to update street geometry and meet the Americans with Disabilities Act (ADA) compliance. For example, levelling the street's surface may remove tripping hazards, which expands available travel paths for mobility-limited and vision-impaired users, as noted by a focus group of vulnerable road users who identified mobility benefits of improved navigation, better quality and more manoeuvrable paving treatment, and fewer areas for vehicles to obstruct pedestrian movement on curbless streets.	US
27	Tyler, N. 2017.	This paper discusses the potential conflicts that can arise when trying to design a transport system to be sustainable, safe and accessible. The paper considers first the overarching vision that drives such an aim and how that determines choices for design and implementation of such schemes. Using the example of a shared space project, Exhibition Road in London, to illustrate how these issues come to arise and how research could help to resolve them, the paper then considers how science is able to support better design and implementation, In accessibility terms, accessibility has been achieved for most of the population, both pedestrians and vehicle occupants. However, whether it has worked well for people with mobility problems is much more in doubt and further research is needed to establish who is – and, importantly, who is not – using the space. That this involves researching people who do not do something, rather than counting those who do.	UK
28	Jayakody, R., Keraminiyage, K., Alston, M., Dias, N. 2018.	The shared space concept has been criticised for its practical issues when implemented in some parts of the world. Such issues include difficulties faced by aged people and people with disabilities, harassments faced by the cyclists, etc. This paper explores the methods and approaches that can be used to harness potential advantages of the concept and to overcome its practical issues and criticisms through a detail evaluation of design driven use of space in three case studies within United Kingdom.	UK
29	Gendron, P. 2018.	In an effort to better respond to the needs of all users as the city moves toward improved sustainable mobility for all, the City of Montreal Transportation Branch teamed up with the Nazareth and Louis-Braille Institute's Interdisciplinary Rehabilitation Research Centre (CRIR-INLB) to develop and implement a collaborative research process bringing together engineers, urban designers, rehabilitation experts and mobility impaired persons to identify the universal accessibility parameters to guide the development of new shared streets and the reconfiguration of existing spaces as shared streets.	Canada
30	Brown, K., Norgate, S. 2019.	Overall, evidence suggested that participants' independent mobility was compromised in this safe space. At times participants felt unsafe, disoriented and shocked, which is entirely at odds with the original aspirational intention behind safe spaces. Informal crossings were perceived as a particular challenge, where the safe space design is specifically built around the principles of visually mediated negotiations, which directly impacts individuals who have lost sight. The perceived lack of demarcation between the 'traditional' carriage and any safe spaces was also a concern.	UK
	Autistic Spectrum Disorder
31	Cowan, G. et al, 2018.	Theory of mind is defined as having the ability to attribute mental states not only to oneself, but to other people. It allows for an individual to anticipate what others will do in a given situation. Requirements for problem-solving include orientation, attention, memory, perception, and higher-level cognitive function. A deficit in one or more of these areas may have significant impact on an individual's ability to safely and confidently participate in a shared zone, and by extension, their community.	Australia
32	Earl, R. et al, 2018.	Eye contact may play a role within a shared zone in allowing pedestrians and drivers to communicate their intent to one another, in order to avoid collision and maintain safety, particularly of pedestrians. In individuals with autism spectrum disorder (ASD), gaze processing may be impaired at one or more levels. An individual with ASD may have difficultly or fail to prioritise the eye contact of other individuals. Furthermore, they may have difficulty following and interpreting the gaze of another person.	Australia
	Engagement and consultation
33	Imrie, R. Kumar, M. 2011.	Most local authorities consulted are developing shared space schemes but not fully shared surfaces as features delineating pavements and roads are retained, though such delineations are not always able to be detected by people with sight loss. There is, at present, insufficient evidence to support some of the positive claims made for shared space projects, and some doubt about the relevance of accident statistics that claim to demonstrate their safety.	UK
34	Imrie, R. 2013.	Drawing on a study of English local authorities, the author contests that data indicate that while the problems posed by shared space are acknowledged by some policy officers with responsibility for the (re)design of street spaces, the views and feelings of vision-impaired people are not a significant part of the policy-making process.	UK
35	Hammond, V., Musselwhite, C. 2013.	The kerb height issue (50mm high) more than anything else made people wary of the street and in some cases even put people off using the street altogether. The kerb edge problem was further compounded by poor contrast in material colour. The issue of the elimination of the kerb in shared space has long been cited as a problem for blind and partially sighted pedestrians who use a long-cane or a guide dog for navigation. However, findings from this research suggest blind and partially sighted people concluded that a kerb was not necessary but that a tactile edge could be used instead. Hence, it is not shared space per se that might stop vulnerable pedestrians, including blind and partially sighted people, from using the space, reducing their independence, but nuances of design which can be changed as appropriate.	UK
36	Karndacharuk, A., Wilson, D., Dunn, R. 2016.	This paper presents the findings of a qualitative analysis using on-street perception and expert interview surveys of city centre streets that have been transformed into shared spaces in Auckland, New Zealand. The principal purpose was to investigate how well the shared streets performed, especially in relation to movement, access and place functions. Place-making; pedestrian focus; changing vehicle behaviour; economic impetus; and safety for all road users were key the five shared space objectives. In terms of shared spaces, these should provide a safer environment for all users, including the elderly, the disabled and children. The performance indicators include crash history, injury severity and costs, user demography and number of user conflict. In general accordance with what was suggested in a report prepared for the UK Department for Transport, the performance criteria (variables) based on five shared space objectives. The performance criteria of 'Pedestrian' and 'Safety' have a commanding influence over the other performance measures and eventually the perceived success of an urban shared space. The 'Safety' objective was consistently perceived to be the most important performance criterion across the three shared spaces and the control site based on the questionnaire surveys of the 400 on-street participants as well as the results from the expert interviews. Given that the quantitative research also demonstrated the strong association between the 'Safety' objective and the 'Pedestrian' and 'Vehicle' performance criteria, it is therefore reasonable to conclude that these three themes of performance attributes are required to be integrated into the street design, operation and maintenance process for successful shared space implementation.	New Zealand
37	Audrey, S., Leonards, U, Damens, D. 2017.	Walking and cycling in urban areas require appropriate infrastructure. Where shared use is a design solution, it should be considered from the perspective of a variety of users. Space, speed, surfaces and signage can all contribute to conflict between users. Clear guidance relating to behaviour on shared use routes is required and should be promoted.	UK
38	Lowe et al, 2015.	The paper details the approach taken to establish the Disability Design Reference Group (DDRG) in order to support meaningful and appropriate consultation, using the life experience and technical knowledge of disabled people to inform the development of Metrolink infrastructure. The paper addresses design challenges through site visits and the structure, governance, and processes of the DDRG. Clear processes and protocols evolved to ensure that consultation activities result in maximum accessibility benefits for Metrolink users.	UK

Annex A2 - Included studies

Reviews

Commission for Architecture and the Built Environment, 2008. Briefing. Civilised Streets. London: CABE.

Edquist, J., Corben, B. 2012. Potential application of Shared Space principles in road design: effects on safety and amenity, Monash University.

Norgate, S. 2012. Accessibility of urban spaces for visually impaired pedestrians, Municipal Engineer, 165 (ME4) pp. 231-237.

Karndacharuk, A., Wilson, D. J., Dunn, R. 2014. A review of the evolution of shared (street) space concepts in urban environments. Transport Reviews, 34(2), pp. 190-220. https://doi.org/10.1080/01441647.2014.893038

Houtekier, C. 2016. Literature review: identification of universal accessibility parameters of shared streets in the context of the renovation of Saint-Paul Street in Old Montreal. Longueuil: Center Research Center - INLB Site, CISSS Montérégie-Center.

Asadi-Shekari, Z., Moeinaddini, M., Aghaabbasi, M., Cools, M. 2019. Exploring effective micro-level items for evaluating inclusive walking facilities on urban streets (applied to Johor Bahru, Malaysia), Sustainable Cities and Society, 49: 101536.

Gamache, S. et al, 2019 Mapping review of accessible pedestrian infrastructures for individuals with physical disabilities, Disability and rehabilitation: Assistive Technology, 14(4): pp. 410-422.

Individual studies: Design and use

Shared space, safe space. Meeting the requirements of blind and partially sighted people in a shared space, 2008. Ramboll Nyvig for Guide Dogs for the Blind.

Thomas, C. 2008. Discussion: Shared space-safe space? Proceedings of the Institution of Civil Engineers - Municipal Engineer, 161(1): pp. 59-60.

Childs, C., Boampong. D., Rostron, H., Morgan, K., Eccleshall, T., Tyler, N. 2009. Effective Kerb Heights for Blind and Partially Sighted People. Research Commissioned by The Guide Dogs for the Blind Association (Guide Dogs). UCL: London.

Right of Way & Road Safety: Inclusive Mobility, 2010. Hong Kong Society for Rehabilitation. 12th International Conference on Mobility and Transport for Elderly and Disabled Persons. Hong Kong Society for Rehabilitation.

Parkin, J., Smithies, N. 2012. Accounting for the needs of the blind and visually impaired people in public realm design, Journal of Urban Design, 17(1): pp. 135-149.

Havik, E., Melis-Dankers, B., Steyvers, F., Kooijman, A. 2012. Accessibility of shared space for visually impaired persons: An inventory in the Netherlands, British Journal of Visual Impairment, 30(3): pp. 132 –148.

Kaparias, I., Bell, M., Miri, A., Chan, C., Mount, B. 2012. Analysing the perceptions of pedestrians and drivers to shared space, Transportation Part F, 15(3): pp. 297-310.

Karndacharuk, A., Wilson, D., Dunn, R. 2013. Analysis of Pedestrian Performance in Shared-Space Environment, Transportation Research Record, 2393, pp. 1–11. DOI: 10.3141/2393-01

Bruneau, J., Morency, C. 2014. Shared Spaces in Canada: an evaluation of their applicability using focus-groups, Transportation 2014: Past, Present, Future. Conference and Exhibition of the Transportation Association of Canada.

Moody, S. Melia, S. 2014. Shared space – research, policy and problems, Proceedings of the Institution of Civil Engineers, http://dx.doi.org/10.1680/tran.12.00047

Havik, E., Steyvers, F., Kooijman, A., Melis-Dankers, B. 2015. Accessibility of shared space for visually impaired persons: A comparative field study, British Journal of Visual Impairment, 33(2): pp. 96-110.

Matthews, B, Hibberd, D and Speakman, K. 2015. The impact of street accessibility on travel and independence for disabled people. In: 14th International Conference on Mobility and Transport for Elderly and Disabled Persons (TRANSED), 28-31 Jul 2015, Lisbon, Portugal.

Smithies, N. 2015. Appropriate public-realm design for the blind and partially sighted, Proceedings of the Institution of Civil Engineers, 168(6): pp. 43-50.

Almeida, M. 2016. Age-Friendly Walkable Urban Spaces: A Participatory Assessment Tool, Journal of Housing for the Elderly, 30:4, 396-411.

Bates, D. 2016. Briefing: Retaining blind access in town streets and shared spaces, Proceedings of the Institution of Civil Engineers, Urban Design & Planning, 169(3): pp. 123-128.

Earl, R. et al. 2016. Visual search strategies of pedestrians with and without visual and cognitive impairment in a shared zone: A proof of concept study, Land Use Policy, 57: pp. 327-334.

Moura, F., Cambra, P., Gonclalves, A. 2017. Measuring walkability for distinct pedestrian groups with a participatory assessment method: A case study in Lisbon, Landscape & Urban Planning, 157: pp. 282-296.

Sauer, C., Mastaglio, B. 2017. Assessing the state of practice of the role and siting issues related to curbless streets in an urban context, Transportation Research Record, 2605, 2017, pp. 61–71.

Tyler, N. 2017. Safety implications and sustainability: The importance of micro-scale outcomes to an equitable design for transport systems, IATSS Research, 41(2): pp. 57-65.

Jayakody, R., Keraminiyage, K., Alston, M., Dias, N. 2018. Design factors for a successful shared space street (SSS) design, International Journal of Strategic Property Management, 22(4): pp. 278-289.

Brown, K., Norgate, S. 2019. Barriers and facilitators for blind and visually impaired users of shared space, Proceedings of the Institution of Civil Engineers – Municipal Engineer, https://doi.org/10.1680/jmuen.18.00063

Gendron, P. 2018. Shared Streets Accessible to All: A Collaborative Research Initiative to Establish Design Parameters in Quebec. Transportation Association of Canada.

Autistic Spectrum Disorder

Cowan, G. et al, 2018. Fixation patterns of people with and without Autism Spectrum Disorder: Do they differ in shared zones and zebra crossings? Journal of Transport and Health, 8: pp. 112-122.

Earl, R., Falkmer, T., Girdler, S., Morris, S., Falkmer, M. 2018. Viewpoints of pedestrians with and without cognitive impairment on shared zones and zebra crossings, PLOS ONE, 13(9): e0203765. https://doi.org/10.1371/journal.pone.0203765

Single studies: Engagement and Consultation

Imrie, R. Kumar, M. 2011. Shared space and sight loss: policies and practices in English local authorities. Research Findings No. 33. Thomas Pocklington Trust: London.

Imrie, R. 2013 Shared space and the post-politics of environmental change, Urban Studies, 50(16): pp. 3446-3462.

Hammond, V., Musselwhite, C. 2013. The Attitudes, Perceptions and Concerns of Pedestrians and Vulnerable Road Users to Shared Space: A Case Study from the UK, Journal of Urban Design, 18:1, pp. 78-97.

Lowe, A., Richardson, S., Partington, D. 2015. Achieving inclusive design: consultation with disabled users, Municipal Engineer, 168: ME1, pp. 45-53.

Karndacharuk, A., Wilson, D., Dunn, R. 2016. Qualitative evaluation study of urban shared spaces in New Zealand, Transportation Research Part D, 42: pp. 119-134.

Audrey, S., Leonards, U, Damens, D. 2017. Shared use of routes for people who walk or cycle: Addressing the challenges, Journal of Transport & Health, 5: S P57-S58.

Rebernik, N., Marusic, B., Bahillo, A., Osaba, E. 2019. A 4-dimensional model and methodological approach to inclusive urban planning and Design for ALL, Sustainable Cities & Society, 44: pp. 195-214.

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