Economic, Environmental and Social Impacts of Changes in Maintenance Spend on Local Roads in Scotland

Appendix B Results of Literature Review

The literature was reviewed against each of the criteria within STAG. Five key questions were used to assess the relevance of each document:

  • Does the document add any value or provide useful information for this study?
  • Which impacts, activities and assets does the document cover?
  • Where is the evidence from? How strong or significant is the evidence? (For example, higher relevance has been assigned to reports which focus on the UK and Europe).
  • What are the key themes and messages?
  • Of what value or relevance is this study to Scotland?

Table B.1 shows each of the STAG criteria and provides an overview of the relevant information identified in the literature review.

Table B.1 Summary of information provided by the literature review
Criterion Sub-criterion Users/Asset/Activities Description of impact due to shortfall in maintenance
Environment Noise and Vibration Pavement (i.e. carriageway) TRL's community severance report (James, Millington, & Tomlinson, no date) made reference to anecdotal evidence of traffic noise created by the arterial road through the community, but provided no evidence that this had increased as a direct result of reduced maintenance.

From research carried out in the UK and in other European countries (Abbott, Morgan, & McKell, 2010), the acoustic performance of all surface types deteriorate with surface age, particularly as the surface reaches its end of life. Generally, it has been shown that there is a simple linear relationship between noise increase and age.

Indicative results from an on-going research programme in the UK suggest that for dense surfacings such as 20 mm HRA the acoustic deterioration is about 0.2 dB(A) per year for high speed roads and for SMA type thin surfacings about 0.5 dB(A) per year. The study also showed that the acoustic performance of porous asphalt surfacings also deteriorated with age at a similar rate as thin surfacings for high-speed roads but for low speed roads the deterioration for light vehicles increased to about 0.9 dB(A) per year.

A guidance note published by the Road Surface Dressing Association (Road Surface Dressing Association, 2008) showed that surfacing dressings can provide a viable surfacing option that is more cost-effective than alternatives (such as thin surfacing) without generating an unacceptable level of noise. This is particularly important at this time where Local Authorities are working with limited budgets.

Therefore, this shows that reduction in road maintenance could lead to an increase in noise and vibration. However, the use alternative treatment options such as surface dressings over the more expensive thin surfacing have been shown to provide an economic and acceptable surfacing option without impacting on the level of noise.
Pedestrians According to Living Streets (Living Streets, 2010) noise pollution particularly in towns and cities, can make conditions for walkers unpleasant at best and a health issue for some people. It can be a disincentive to walk close to or along main roads or in areas of stationary vehicles. It also states that noise makes casual conversation much more difficult. Thus, an increase in noise and vibration through possibly a reduction of maintenance could have an impact on pedestrian's choices and way of life.
Structures, Street Cleaning, Barriers, Footways and Drainage No evidence found.
Global and Local Air Quality Pavement (i.e. Carriageway) and Street Cleaning TRL's community severance report (James, Millington, & Tomlinson, no date) made reference to anecdotal evidence of air quality being affected by the arterial road through the community, but provided no evidence that this had increased as a direct result of reduced maintenance.

In a demonstration study of nonpoint pollution abatement through improved street cleaning practices (Pitt, 1979) street dirt loading was also found to increase more rapidly immediately after street cleaning, and then level off somewhat after several days. One week after street cleaning, approximately 4 to 6lb/curb mile [sic] per day of particulates were lost to the air. This rate increase for longer cleaning intervals. Furthermore, the median particle size of street dirt was also found to increase with time between cleaning and decrease with cleaning. Street cleaning equipment picks up larger particles more effectively than smaller particles. As a result, the study found that the small particles tend to increase in abundance with time.

The report also found that different test area conditions affected performance more than differences in equipment type. Smoother (asphalt) streets were found to be easier to keep clean than streets with oil and screens surfaces or those in poor condition. The street surface loading values after cleaning were always lower on the asphalt streets in good condition as areas with better quality street surfaces had more of the smaller sized particles present.

In conclusion, if carriageways are not cleaned, the accumulation of dirt/dust would contribute to air pollution.
Structures Zhang (Zhang, 2010) mentioned although bridge maintenance (including concrete repairs, painting of steel girders, replacement of moving joint and bearing, waterproofing and deck surfacing) needs to be carried out, these activities use materials, consume energy which contribute to carbon emission. Furthermore, bridge works disrupt traffic, causing queues and detours thus impacting on air quality through carbon emission. Therefore, by inference, it would appear that a reduction of maintenance would result in less carbon emission hence would have less impact on air quality.
Pedestrians According to Living Streets (Living Streets, 2010), air pollution particularly in towns and cities, can make conditions for walkers unpleasant at best and a health issue for some people. It can be a disincentive to walk close to or along main roads or in areas of stationary vehicles. It also states that air pollution also makes it unpleasant to spend time on the street. Thus, an increase in air pollution through possibly a reduction of maintenance could have an impact on pedestrian's choices and way of life.
Footway, Drainage, Cycle-track, Cyclists No evidence found
Biodiversity Lighting Little evidence was found to suggest that street lighting has an adverse effect on biodiversity. However, a key document reported on the potential harmful effects of light pollution on Britain's bat population. The report written by Emery (Emery, 2008) highlights that Local Authorities have a responsibility to avoid contravening the Wildlife and Countryside Act (DEFRA, 1981) which has a requirement not to disturb bats. This includes directly illuminating their roosts or the paths they follow to their feeding grounds.

Years of study reveal that all but 3 of the UK's 17 different bat species will not fly in directly illuminated areas. Bats leave their roosts at night and follow a regular commuting route to feeding areas. If this route is affected by artificial lighting, they can abandon it with potentially catastrophic consequences on their ability to feed (Emery, 2008). This research identifies that reduced street lighting would have a beneficial impact on bats and their habitats.
Vegetation Control Glendinning et al (Glendinning, Loveridge, Starr-Keddle, Bransby, & Hughes, June 2009) made reference to the fact that vegetation is regarded as a benefit that can improve the aesthetic environment and provide visual and noise barriers. Vegetation provides important grassland habitats and migration routes for many native species. This study made reference to the fact that in order to reduce costs in 1975, the UK Department of Transport issued instructions to cease regular grass cuttings on trunk roads and motorways and only to cut in restricted circumstances. This caused a decline in species-rich grassland habitats and scrub encroachment across many roadside corridors. This shows that a lack of vegetation control could prevent the upkeep of grassland biodiversity.
Pavement, Structures and Drainage No evidence found
Visual Amenity, Cultural and Landscape Pavement (i.e. carriageway) Even if Clegg (Clegg, June 2011) commented that poorly maintained surfacing and infrastructure discourages use of the street and dilapidated structures and that potholes, dark lamps and heavy patching can all detract from the perceived quality of the public realm in an area, there is little evidence to suggest that visual amenity is affected by a reduction in carriageway maintenance.
Footway The Social Exclusion Unit report (Social Exclusion Unit, 2003) suggests that poor walking environments and transport links can leave areas isolated and damage community cohesion.

A 2005 study for the Scottish Executive (cited in (Living Streets, 2010) found that the presence of environmental incivilities are likely to have an impact on health and attitudes to the local area in a Scottish context. An 'environmental incivility' is any aspect of the environment that people are capable of discerning through hearing, sight, touch or smell and about which they may be inclined to feel negatively. Examples include 'street level' incivilities such as litter and graffiti. Incivilities most frequently mentioned all had an impact on the walking environment - cat and dog mess, lack of safe play spaces, litter, uneven carriageways, traffic, vandalism, broken glass and lack of pleasant places to walk. Thus, if these incivilities are not dealt with through maintenance, it would have an impact on the visual amenity and use of the footway.
Pedestrians There is a significant amount of research on the 'broken window theory' which refers to the social effects of abandonment that can result in reduced walking, physical activity and recreation in public. Lopez and Hynes (Lopez & Hynes, 2006) have identified certain features of the built environment - such as the presence of sidewalks, streetlights, interconnectivity of streets, population density and use mix - that appear to encourage physical activity and thus reduce the risk of obesity and related health problems. Many factors of the environment in inner cities, including built, physical and social factors, may exert a net negative influence on the health of inner city residents. These factors and conditions include problem land use issues, such as waste sites, infrastructure maintenance and investment issues. Lopez and Hynes accuse a lack of pedestrian amenities for discouraging walking, and a fear of crime keeping people indoors; while unimproved sidewalks decay as utility crews dig up concrete, tree roots push up paved areas, and weather erodes surfaces. Urban neighbourhoods frequently have broken or impassable pedestrian sidewalks which reduces leisure walking.

"Several features of the suburban built environment such as low densities, poor street connectivity and the lack of sidewalks are associated with decreased physical activity and an increased risk of being overweight. But compared to suburban residents, inner city populations (in America) have higher rates of obesity and inactivity despite living in neighbourhoods that are dense, have excellent street connectivity and who's streets are almost universally lined with sidewalks. In the inner city, densities may be lowered because of abandonment and disinvestment" (Lopez & Hynes, 2006).

Indeed, the University of Groningen in the Netherlands conducted 'broken window theory' experiments to discover if signs of vandalism, litter and low-level law breaking could change the way people behave, and found that such conditions doubled the number of people prepared to litter and steal. The researchers' conclusion is that one example of disorder, like graffiti or littering, can indeed encourage another, like stealing - hence clearing up graffiti or littering promptly could help fight the spread of crime (Keizer, 2008).

So, an increase in visual amenity (like graffiti, littering) through lack of maintenance, could encourage the spread of crime hence impacting on the use of public spaces by pedestrians.
Street Cleaning The Code of Practice of Litter and Refuse (DEFRA, 2006) states that management of an area should be focussed on keeping it clean, rather than how often it is cleaned. Graffiti and fly posting, even if partially removed, has an adverse effect on the quality of the environment. The Code suggests that this can lead to an increase in crime, or fear of crime.

It suggests that cleaning litter and refuse alone is insufficient for an area to be considered clean; that "the public would still perceive the area to be defaced [if graffiti and / or fly posting were still present]". It also suggests that further degradation of an area can take place as the local environmental quality decreases.

Therefore, a lack of street cleaning would impact on the visual amenity and consequently could lead to an increase in crime or fear of crime.
Structures, Cycle-track, Lighting, Drainage, Road Users and Vegetation Control No evidence found
Physical Fitness Footway Research conducted by the University of the West of England and partners (Sinnett D. W., 2011) states that the aesthetic quality of a place is the most consistently important factor in relationships between the public realm and recreational walking, health and well-being. Within the cited research, a study by Dempsey (Dempsey, 2008) found that the resident perceptions of a sense of community and attachment to a place were influenced by factors including level of maintenance.

Living Streets (Living Streets, 2010) suggests the absence of facilities or barriers to facilities (e.g. steep hills, busy roads to cross) or the perception that such facilities are inadequate have negative associations with physical activity.
Pedestrians The Walkipedia publication (Living Streets, 2010) states that the quality of the environment in the vicinity of older people's homes has been assessed as a contributory factor in people not taking exercise.

According to the same publication 39% of respondents stated that the presence of path networks contributes to a significant increase in the amount of physical activity in which they participated. Although this is not linked to levels of maintenance directly, it can be inferred that if negative changes to the levels of maintenance impacts on route choice and availability, there may be implications for levels of physical fitness and walking for health.
Street Cleaning A research study by Curtice et al (Curtice, Ellaway, Robertson, G, Robertson, & Morris, 2005), cited by Croucher et al (Croucher, Myers, Jones, Ellaway, & Beck, 2007) suggested that perceptions of the neighbourhood are strongly associated with health and well-being. The study considered the impact of a number of environmental 'incivilities' (including litter, dog fouling, poor street maintenance, absence of safe places for children to play, vandalism and graffiti) on public perception. They found that those who experienced higher levels of street incivilities were prone to higher levels of anxiety, depression, poor health, and smoking than people who are exposed to lower levels of incivilities. The former were also more likely to report increased fear of crime, and be less trustful of others, and be more resigned to the difficulties in their area. Therefore, a lack of street cleaning through possible a reduction in maintenance would impact the people's physical fitness.
Cycle-track, and Road Users No evidence found
Safety Accidents Pavement (excluding skid resistance - addressed elsewhere in the study) According to the ALARM survey (AIA, 2011), 90% of Authorities say they believe that the under-funding of the highway maintenance programme creates a threat to road users' safety with nearly a third of them thinking that the threat is major. Just over half (52%) of Authorities believe that the threat to road users' safety has increased over the past financial year (2010/11), whilst 41% feel it is unchanged.

Another survey conducted by Audit Scotland (Audit Scotland, 2011) commented that road safety is also affected by poor road condition. The survey estimated that over 30,000 Scottish drivers had experienced a near miss with another vehicle or pedestrians due to either hitting a pothole or swerving to avoid one. In addition, in this study, it was estimated that Local Authorities would need to spend on average £167.6m on structural maintenance each year over the next ten years excluding inflation, to maintain the local road network in its current condition. This amounts to an annual shortfall of £45.1m compared to what was spent in 2009/10. The consequences of not spending at this level are forecast to result in a £1 billion decline in the value, and a 10% reduction in the condition of the local road network.

In a study by (Ramdas, Thomas, Lehman, & Young, 2007), two wheeled vehicles were found to be most vulnerable to poor surface conditions, with the worst defects being those that are not visible but have the potential to disturb their balance. Additionally, both motorcyclists and cyclists were reported to often swerve and alter their "line" to avoid noticeable defects, with obvious implications for the safety of all road users. A project undertaken for the Scottish Executive (Granville, Rait, Barber, & Laid, 2001) to explore the attitudes of drivers and cyclists towards one another found that some conflict situations (between drivers and cyclists) were "created by the poor state of repair on the road".

Road surfaces with loose stones were found to be a "serious concern" for motorcyclists, making them feel "particularly unsafe" because they "flew up and hit then as they drove over them".

Therefore, a reduction or lack of maintenance leading to poor road condition would appear to affect road safety for various reasons noted above.
Structures An example of the safety impact of a failure in a structure can be demonstrated by the collapse of the I-35W highway bridge over the Mississippi River in Minneapolis, USA (National Transport Safety Board, 2007). Based on the accident report, the collapse of the bridge was inadequate load capacity due to a design error of the gusset places and inadequate attention to the gusset plates during inspections for conditions of distortion or corrosion. This bridge failure due to major safety issues resulted 13 fatalities and 145 people being injured. Thus, it can be shown that inadequate inspection regime results in a higher risk of catastrophic failure of structures which would consequently have an impact on safety.
Lighting The Police Road Death Investigation Manual (National Policing Improvement Agency, 2007) identifies the responsibility of the Local Authority "when a collision has occurred and highway involvement is alleged, then the Highway Authority should be able to show that it took reasonable measures to ensure that the safety of the road user was not compromised" - highway lighting is an important component of that responsibility (Institution of Lighting Engineers, 2010).

The literature search found a number of pertinent reports that explore the effect of reduced lighting on the health and safety of drivers and pedestrians. In recent years, schemes that switch off street lights all night, or where there is 'partial switch off' or 'part night lighting' have been adopted by some Authorities to make financial savings and meet carbon reduction targets (Institution of Lighting Engineers, 2010).

A number of Local Authorities in England have reported on the results of trials to switch off street lights. (Buckinghamshire County Council, 2010) have reported on an energy saving trial that began in 2007 at seven sites where street lights were switched off (Phase 1), and at a further 39 sites in 2008 (Phase 2) with a total of 1,627 street lights switched off. Findings of the interim report provide significant evidence that switching off street lights does not increase the risks of road traffic accidents.

To date, results of the trial include three year 'before' and 'after' data from Phase 1 sites and two year 'before' and 'after' data from Phase 2 sites. Where lights have been switched off, there is a general reduction in the overall number of collisions:
  • 31% reduction in all injury collisions
  • 32% reduction in all casualties
  • 9% reduction in injury collisions during darkness
In support of this research, a spokeswoman for Buckinghamshire, Sheila MacDonald said "in seven sites monitored there were a total of seven collisions between August and December 2006 when lights were on, and only three in total between August and December 2007 when lights were off" (Tarry, 2008).

A TRL report analysing STATS19 casualty data also found that in a five year study period 21% of accidents occurred in darkness where there was street lighting, with less than 6% of all accidents occurring where there is no street lighting, with lighting having a larger effect on reducing the number of fatal accidents than the number of serious and slight accidents (Crabb, Crinson, Beaumont, & Walter, 2009).

In a comprehensive review of street lighting and road traffic injuries, (Beyer & Ker, 2010) report on the findings of Elvik (Elvik, An analysis of official economic valuations of traffic accident fatalities in 20 motorized countries., 1995) and (Elvik, Hoye, Truls, & Sorensen, 2004) who concluded that street lighting may reduce night time fatalities by as much as 65% and night-time injuries by 30%. He added that "increasing the level of lighting by up to double the previous level has a limited effect on the number of crashes, but is not so pronounced as for newly installed lighting on a previously unlit road". Hence, it can be deduced that if new lighting has a positive impact on the number of crashes, then removal of existing lighting will have an equally negative effect, particularly as street lighting allows drivers to detect intersections sooner, decelerate earlier and reduce speed with improvements in driver visual certainty (Beyer & Ker, 2010).

Certainly, another trial of 're-lighting' in Wakefield between 2004-08 helped reduce vehicle collision and damage by 50%, reduced night time accidents by 31% and night time fatalities fell from 9 to 0 during the same period (Institution of Lighting Engineers, 2010). In a research study for Transport for London (Transport for London, 2009), the main user priorities for footways and carriageways are maintenance and good lighting. About half of all respondents thought that in the dark, the risk and hazards associated with some or all condition defects (principally cracks and potholes for pedestrians) is higher than that in daylight. The literature provides mixed evidence as to the benefits and disbenefits of turning off street lights with respect to road safety, and there would appear to be some bias from the source of the evidence, with Buckinghamshire County Council finding a reduction in accidents after switching off the lights, and the Institution of Lighting Engineers finding a reduction in accidents after implementing new lighting. Nevertheless, there have been reported cases of fatalities directly linking the lack of lighting with road traffic accidents, including Buckinghamshire where a Coroner said "the driver had no chance to see the lady crossing the road without any street lights operating" (Institution of Lighting Engineers, 2010).
Footway A paper by (Borges, 2007) outlines the specific mobility difficulties faced by an aging population in Europe, and references the role of the built environment in terms of accessibility and perceptions of safety. It states that the largest barrier to older people's mobility are psychophysical related impairments associated with walking and accessing public transport such as uneven and narrow carriageways. It continues exploring the worry of older people in terms of their safety, for example fear of crime, falling over and becoming injured.

This is reflected in earlier research into older people's transport needs by (Marsden, Jopson, Cattan, & Woodward, 2007). Their research found that older people's ability to get out and about was affected by environmental, social and psychological factors that include uneven surfaces and obstacles and a fear of being knocked or falling over.

Research for Transport for London (Transport for London, 2009) aimed to gather user perceptions and preferences related to condition defects of various types, extents and severities and to seek to understand tolerances to nuisance and disruption to maintenance works required for remedy. About 75% of the respondents thought that condition defects could have an impact on safety. About half of all respondents thought that some or all condition defects would have a worse impact in the dark, principally cracks and potholes for pedestrians.

Therefore, based on these studies, it can be concluded that deterioration in the footway surface through lack of maintenance would have an impact on safety especially for users with mobility difficulties.
Pedestrians TRL's community severance report (James, Millington, & Tomlinson, no date) made reference to anecdotal evidence of increased risk of road traffic accidents created by the arterial road through the community, particularly where pedestrians were deterred from using the footbridge and subways, leading to dangerous crossing activity across the dual carriageway. However, it provided no evidence that this activity had increased as a direct result of reduced maintenance.

TRL research for the Department of Transport (Ramdas, Thomas, Lehman, & Young, 2007) found that elderly and/ or disabled road users are "most critical" of surface conditions. Unlike many other groups, they are "highly aware" of surface problems. This is mainly because of "fears for personal safety and discomfort". On footways, "tripping or falling on raised or lowered paving slabs and potholes is a particular concern". As a result of this, there is a greater tendency to take an alternative route to avoid poor surfaces. This can take the form of a deviated path (e.g. onto the carriageway) or a different route altogether, with clear implications for the accessibility of destinations for particular pedestrian types who are unable to walk far.
Cyclists "Department for Transport guidance on the appraisal of walking and cycling schemes (Department for Transport, 2010)refers to "perceived safety or the fear of potential accidents" being mentioned by cyclists as being a "major barrier" to cycling and cycling more often. However, the Department for Transport report does not link this fear to levels of maintenance.

A TRL report undertaken for the Department for Transport (Ramdas, Thomas, Lehman, & Young, 2007) found that cyclists are mainly concerned about step changes (>2mm) in their line of travel caused by potholes, sunken or raised ironworks, failed potholes and debris in the carriageway. Given that cyclists generally travel to the left of the travel lane, they are particularly susceptible to edge deterioration and raised ironworks. Cyclist perceptions uncovered in the study suggest that cycle lanes are often covered in "debris".

The study found that this can force cyclists to change their route, to avoid poor surface conditions. For some this may mean swerving into other parts of the road. Any deviation of the cyclists' 'line' is seen as very dangerous. Poor surfaces, especially at the edge of the road, may cause a sudden deviation that would then put the cyclist and other road users in danger."

Therefore, poor surfaces potentially through lack of maintenance may compromise the safety of cyclists.
Cycle-track, Signs, Barriers and Road users No evidence found
Security Structures Although there is a perception that there are safety issues associated with subways (West Midlands Council, 2006) as they suffer from vandalism due to their secluded nature, poor lighting and lack of maintenance, there is little evidence on the impact of security as a result of reduced structure maintenance.
Footway London Borough of Greenwich Local Implementation Plan (London Borough of Greenwich, 2004) included aspects of maintenance for trees and foliage to reduce hiding areas, dark areas and to limit escape routes.

The Social Exclusion Unit (Social Exclusion Unit, 2003) report states that "crime and the fear of crime can deter walking, cycling and the use of public transport".

Social interaction in the street environment has been linked with lower crime rates (Sinnett, Williams, Chatterjee, & Cavill, 2011). The study states that the perception of safety (distinct from reported crime levels), fear and mistrust have all been linked to levels of maintenance or presence of incivilities (e.g. graffiti and vandalism) in a neighbourhood. The overall level of safety in a neighbourhood is affected by its appearance, crime rate and level of incivilities, suggesting that factors which affect the perceptions of safety are critical in contributing to overall levels of safety.
Lighting A number of literature reports point to evidence that street lighting has a positive impact on crime reduction and fear of crime, as well as assisting the emergency services after dark and promoting the evening economy offering safe and secure access to public transport, evening work, education and leisure activities (Institution of Lighting Engineers, 2010). One such report by children's charity PLAN highlighted that 91% of 13-18 year olds said better street lighting would make a big difference to whether they felt safe on the streets (Institution of Lighting Engineers, 2010). Furthermore, a Home Office study from 1991 found that lighting was more likely to have a positive impact on the public's fear of crime, than on the incidence of crime itself, stating that "better lighting by itself has very little impact on crime" (Tarry, 2008).

Certainly, evaluation studies undertaken in Bristol, Dudley, Stoke-on-Trent, Dover and Birmingham showed that improved lighting led to a 29% decrease in crime, although night time crimes did not decrease more than daytime crimes, suggesting a 'community pride' theory where improved lighting signals community investment leading to community cohesion and informal social control, rather than a 'deterrence/surveillance' theory whereby improved lighting leads to increased surveillance of potential offenders by improving visibility and increasing the number of people on the street thus creating a deterrent to criminals: "As a highly visible sign of positive investment, improved street lighting might reduce crime if it physically improved the environment and signalled to residents that efforts were being made to invest in and improve their neighbourhood. In turn, this might lead them to have a more positive image of the area and to have increased community pride, optimism and cohesion" (Swedish National Council for Crime Prevention, 2007).

In the 2004 Local Implementation Plan, London Borough of Greenwich included the pledge to improve street lighting to "reduce the risk of accidents and violent attack" (London Borough of Greenwich, 2004).

In a Guide for Crime Reduction Professionals, the Institution of Lighting Professionals (Institution of Lighting Professionals, no date) highlights that the aesthetic value of a lighting installation is important as the daytime street scene suffers greatly if fittings, materials or paint finishes are of lesser quality. The shabby appearance of lighting street furniture can send the wrong signals to the community and contribute to a cycle of grime, crime and decline.
Pedestrians The TRL report on community severance (James, Millington, & Tomlinson, no date) made reference to anecdotal evidence that poor design and a lack of maintenance of mitigation measures (subways and footways) across the arterial road created an environment of fear among vulnerable pedestrians.

The West Midlands Local Transport Plan on Bridge Maintenance (West Midlands Council, 2006) identified safety and security issues in connection with subways: "Many subways suffer from vandalism and are used for anti-social behaviour. They are often perceived by the public as being unsafe generally due to their secluded nature, poor lighting and lack of maintenance. Many subways are being infilled and replaced by alternative facilities as part of other programmes. However, it is recognised that subways often provide the safest routes for pedestrians crossing roads and a number of Authorities have a programme of works to improve them so as to encourage their use and reduce the amount of vandalism".

According to a study by Sinnett et al (Sinnett, Williams, Chatterjee, & Cavill, 2011), people walk more when they feel their environment is safe, well maintained and lively, and the report links the level of investments in the walking environment with places which are perceived to be more attractive and safe. A study in Glasgow referenced in the research found that those who felt their neighbourhoods were safe to walk in after dark were 70% more likely to walk at least five times per week than those who did not feel their neighbourhoods were safe, with clear implications for health and fitness.
Street Cleaning The Code of Practice of Litter and Refuse (DEFRA, 2006) states that management of an area should be focussed on keeping it clean, rather than how often it is cleaned. Graffiti and fly posting, even if partially removed, has an adverse effect on the quality of the environment. The Code suggests that this can lead to an increase in crime, or fear of crime.

This is echoed by a Living Streets publication (Living Streets, No date) which also suggests that maintaining the cleanliness of an area is more important than the frequency of its cleaning regime. The Clean Glasgow campaign, cited in the document, "recognises the link between anti-social behaviour and the environment". Furthermore, the "cleanliness and safety of the city is a key issue for Glasgow citizens and businesses". One of the visions from the campaign is "A Glasgow free from litter, graffiti and other grime crime", which suggests that they have found a relationship between street cleanliness (this is assumed to include incivilities like graffiti) and perceptions of crime.
Pavement, Cycle-track and Cyclists No evidence found
Economy (Transport Economic Efficiency) Vehicle Operating Cost Pavement (in addition to quantitative effects analysed elsewhere in the study) Crick (Crick, 2005) mentions that reduced funding is taking its toll on the condition of the roads with a more than doubling of the number of visual defects, including potholes and cracks over the past 10 years. Potholes, defects and cracks result in an increase in the level of compensation claims Local Authorities receive from road users for damage to vehicles. According to highways departments in Wales the knock-on effect of lack of maintenance lead to a 50% increase in the amount of money paid out (£790,000) by Local Authorities in Wales in 2004.

In addition, based on a public survey, The Asphalt Industry Alliance (Asphalt Industry Alliance, 2011) estimated that on average those affected by damage to vehicles because of poorly maintained roads spent £340 on repairing them (£500 spent in the West Midlands area and £200 spent in the South West). This figure is further confirmed by two other studies:
  • TRIP (TRIP, April 2011) estimated that Oklahoma motorists spent an additional vehicle operating cost of $425-$662 (about £260-£414) per motorist per year as a result of driving on roads in poor condition.
  • A survey undertaken as part of the Maintaining Scotland's Roads study (Auditor General for Scotland and Accounts Commission 2011) estimated that over a third of Scottish motorists have suffered car damage because of potholes. The average cost of repairing damage to their vehicles is thought to be between £133 and £220 per motorist per year. This cost related to pothole-related car repairs such as suspension problems, burst tyres, chipped windscreens and paintwork damage.
All these studies have shown that a lack of maintenance resulting in the increased levels of potholes, defects and cracks in the road pavement (i.e. carriageway) would result in increased vehicle operating cost ranging from £133 to £500 per motorist per year.
Structures No evidence found
Accessibility and Social Inclusion Community Accessibility Pavement Research carried out by HITRANS (McDowall & Adams, 2008) and (Halcrow, September 2004) explored the current conditions and constraints of locally significant roads (specifically Lifeline Rural Roads) in Scotland and the economic and social impacts of investment in the network. These studies concluded that many of these 'lifeline roads' are currently in a poor standard and in need of repair and consequently there is a significant constraint on the ease and comfort with which residents can access employment and lifeline services such as health, education, retailing and banking. Therefore, these studies included an economic analysis on a scheme-by scheme basis of the impact of investment on nine key routes in terms of journey times and reliability, diversionary impacts, generated traffic, accident reductions impacts, total user benefits. For example, a proposed road improvement scheme (widening, re-surfacing, small scale works on structures and drainage) over 17.1 km costing £0.5m would result in an estimated journey time saving of 1 minute, vehicle operating cost savings of 1 pence per trip and a total user benefits of £41k per year.

The Social Exclusion Unit Report (Social Exclusion Unit, 2003), Making the Connections, stated that "busy roads can divide and damage local communities and restrict walking, especially among children and elderly people". In the same report, "the building of the M32 in Bristol severed one traditional neighbourhood (Easton) into two parts".

While these case study examples do not provide firm evidence that a reduction in road maintenance would impact on the community accessibility, they do illustrate that a lack of road improvements through investment will impact on the social and economic fabric of remote communities. It can be inferred that community accessibility especially in rural areas are reliant on the quality, reliability or availability of the road network and this can have an impact on the long-term sustainability of communities.
Structures In recent years there have been incidences involving the collapse of bridge structures in both Britain and the United States caused by flooding and structural design failure respectively. These cases, while not directly caused by reduced maintenance, demonstrate the wide reaching and adverse impacts of severing access across a river that services local communities. In November 2009, severe flooding across Cumbria led to the closure of 16 bridges and 25 roads causing widespread travel chaos. Six bridges collapsed and Calva bridge which serviced the town of Workington was condemned resulting people on the North side of the town having to make a 40 mile detour to reach the town centre. According to the BBC, a teacher in Wigton said his usual journey to work is 15 miles and takes 20 minutes, but as the two main bridges out of Cockermouth are closed, he now has to take an alternative route which is 40 miles. Workington MP Tony Cunningham said "the lack of bridges meant people were being forced to travel 90 miles for a journey that would usually take a minute and a half, and temporary structures may be needed".

A Minnesota newspaper also reported on the economic effects that the bridge collapse on Interstate Highway I-35W had in August 2007 (Cormany, 2008). Small retail establishments including the Johnson Avenue Northeast businesses especially have reported revenue declines of up to 50%. The article reports that the roads immediately surrounding the retail district on the 2800 block of Johnson Street Northeast are open as usual, although drivers who once passed through the area to or from I-35W South seem to be finding other routes, and as a result local merchants say traffic flow has reduced significantly. Another retailer located at the final exit before southbound I-35W crosses the Mississippi River reported an 80% drop in sales immediately after the bridge accident (Cormany, 2008).

These case study examples illustrate how the removal of key infrastructure assets (in this case through the catastrophic failure of the bridge structures) can have devastating socio-economic impacts on the local communities and the wider commuting populations. Both these bridge collapses resulted in fatalities, and have been responsible for the complete severing of road links across the rivers that separate the settlements. One can therefore infer from these examples, that where such vital links are severed, either through the removal of an asset or possibly a shortfall in maintenance resulting from austerity measures, the community severance impacts are likely to be extremely serious.
Footway Living Streets (Living Streets, 2010) suggest that the quality of the walking environment as evidenced by their community street audits confirms the view that people's perceptions of safety are an important factor in decision-making about going out or participating in community life.

According to Living Streets (Living Streets, 2010), a 2007 study undertaken in Scotland reported that the majority of people walking along in the local neighbourhood after dark felt very safe or fairly safe (72%) but with 23% feeling a bit unsafe or not safe at all. In the 15% most deprived areas, this figure rose to 37% feeling a bit unsafe or not safe at all. There is no evidence on whether people felt that their community was safe because the footway is well maintained.
Cycle-track Guidance from the Department for Transport in relation to the appraisal of walking and cycling schemes (Department for Transport, 2010) suggests that cycling and walking schemes may "positively affect severance by reducing barriers to opportunities and destinations". The guidance suggests that this can be achieved by addressing indirect routes, a lack of provision, safety concerns and levels of information for cyclists. However, there is no research cited which specifically links a lack of maintenance of cycle-track facilities to levels of community severance.
Pedestrians Research conducted by TRL on community severance (James, Harper, Reid, McColl-Grubb, & Tomlinson, 2004); (James, Millington, & Tomlinson, no date); and (Tomlinson & James, 2005) explored how a community in the South West of England experiences community severance effects. The qualitative empirical study found that mitigation measures used to reduce severance impacts, for example subways and footbridges cause 'secondary severance' effects whereby the mitigation measure itself creates a barrier to access because of poor maintenance. The presence of graffiti, rubbish and vomit were cited as particular problems, and vandalised lighting and mirrors, as well as flooding were reported as contributing to anti-social behaviour and criminal activity.

A TRL study in 2008 (Bradbury, Tomlinson, & Branning, 2008) suggested that "there is no evidence to support the claim in the DMRB Volume 11 that residents adjust to severance over a period of years".

The Social Exclusion Unit (Social Exclusion Unit, 2003) report states that "poor transport as a barrier to work may contribute to higher benefit payments, reduced tax contributions, missed health appointments, delays in patient discharge from hospital, course drop-outs in education. The impact of transport through pollution and pedestrian deaths has significant immediate and long-term costs", however this is not linked to levels of maintenance.

Definitions of community severance refer to physical barriers, psychological or perceived barriers (including traffic noise and personal security fears) and the social impacts of reduced community interaction. However, existing definitions of community severance do not include changes to existing infrastructure, for instance caused by reductions in maintenance. The research showed that the lack of maintenance of subways and footbridges put in place to mitigate against severance effects had in itself caused severance impacts, principally to deter people from using them. However, the study did not determine the nature of maintenance withdrawal or how it contributed to the severance effects over time.
Road Users An investigation into the socio-economic impacts of road condition on low volume roads (Johansson 2004) explored the concept of 'lifeline rural roads' in the Scottish highlands. It showed that where a transport link which has no substitute, or where the substitute entails a considerable increase in time or money expenditures, where any diminution in the quality, reliability or availability of the former is likely to have a significant impact on the social or economic viability of an affected community.
Drainage and Cyclists No evidence found
Comparative Accessibility Structures Marsden et al (Marsden, Jopson, Cattan, & Woodward, 2007) research into the barriers faced by older people found that steps were a particular challenge for many older people. However, there was no evidence to suggest that this problem is particularly linked to maintenance.
Footway In Marsden et al (Marsden, Jopson, Cattan, & Woodward, 2007) research, inadequate footways were found to be a problem cited by many older people when exploring barriers in the walking environment. Participants talked about changing their route to avoid areas with bad paving. This included them being badly maintained or even not being where they wanted to walk.

Ramdas et al (Ramdas, Thomas, Lehman, & Young, 2007) cited a study by DPTAC (Disabled Persons Transport Advisory Committe (DPTAC), 2002) which found that visually impaired people were more likely to be dissatisfied with road and footways than other disabled users and about half (48%) of the disabled people said that they would go out more if the conditions for walking were better.

This was also found in Burnett's report (Burnett, 2005) which reported that poor quality carriageways, hilly terrain, inadequate street lighting, noise and pollution, threats to safety and inconsiderate behaviour towards older, vulnerable people are cited as 'tipping points' - key elements in deciding whether to go out or not, when and where.

Therefore, it could be interfered that accessibility especially for visually impaired people would improve if the footway condition is better and vice versa.
Pedestrians Ramdas et al (Ramdas, Thomas, Lehman, & Young, 2007) cited a study by DPTAC (Disabled Persons Transport Advisory Committe (DPTAC), 2002) which found that "visually impaired people were more likely to be dissatisfied with road and footways than other disabled users and about half (48%) of the disabled people said that they would go out more if the conditions for walking were better".

A study by Lavery and Davey (Lavery & Davey, 1996) explored whether the increased use of low floor buses will have a positive effect on the travelling population, particularly older people and those who suffer from mobility impairments. In doing so, the study addressed travel behaviours and barriers for these two groups which are more fundamental than boarding and alighting public transport vehicles; namely those related to the built environment which can prevent people from accessing public transport stops. The National Travel Survey 1991-93 (Department of Transport, 1994) cited within the research states that "one of the three greatest barriers to bus travel by those with mobility impairments is getting to the bus stop".

The paper suggests that a high proportion of the most prevalent barriers to walking presented by the built environment relate to surfacing quality, some of which can be linked to surface decay and broken paving stones. Tranter et al (Tranter, Slater, & Vaughan, 1991) indicates that "four out of the six most prevalent built environment barriers" are related to surfacing:
  • Uneven carriageways
  • Kerbs that don't drop smoothly
  • Awkward kerbs
  • Broken paving stones
The research project included in the study included focus groups, interviews and travel diaries amongst older people in Northern Ireland. The results of the research supported previous research in the area, with stated barriers to walking uncovered by the research include both trip hazards and the poor maintenance of footways.

A paper by Borges (Borges, 2007) outlines the specific mobility difficulties faced by an aging population in Europe, and references the role of the built environment in terms of accessibility and perceptions of safety. It states ""the largest barrier to older people's mobility are psychophysical related impairments associated with walking and accessing public transport such as uneven and narrow carriageways"". It continues exploring the worry of older people in terms of their safety, for example fear of crime, falling over and becoming injured.

Research undertaken for Transport for London (Transport for London, 2011) gathered minimum and preferred levels of service from pedestrians in London, with regard to specific footway condition defects such as cracking, subsidence, flooding, depressions and raised or sunken ironworks. More than a third of the sample had a long-term physical or mental disability (including those related to old age) which limited their daily activities or work that they could do. Pedestrians with a mobility impairment were slightly more likely to say the condition of the Red Route Network was poor or very poor, as well as slightly more likely to say the condition was good than those with a visual impairment or without an impairment. This suggests that there are pedestrian types with much greater sensitivity to surface conditions."
Pavement, Cycle-track, and Road users No evidence found