4 Design Standards

4 Design Standards

4.1 Road Link Features

4.1.1 Introduction

This section describes the key inclusive design elements in the design of road link features.

4.1.2 Lay-bys

TD69/07 (DMRB 6.3.3) sets out the design of lay-bys. Transport Scotland requires the following enhancements to make lay-bys accessible to disabled people.

4.1.3 Parking Lay-bys (Type A)

For Type A lay-bys, a dropped kerb is required to provide access to the footway at the rear of the lay-by to assist people with mobility impairments. An accessible parking bay is to be provided at the exit end of the lay-by.

Figure 1: Type A lay-by

Figure 1 Type A lay-by

4.1.4 Parking Lay-bys (Type B)

For Type B lay-bys, a dropped kerb is required to provide access to the footway at the rear of the lay-by to assist people with mobility impairments. An accessible parking bay is to be provided at the exit end of the lay-by.

Figure 2 a & b: Type B lay-by

Figure 2 a and b Type B lay by

4.1.5 Parking Lay-bys (Type A Lay-by with Trading Facility)

For Type A lay-bys with a trading facility a dropped kerb is required to provide access to the footway at the rear of the lay-by to assist people with mobility impairments. An accessible parking bay is to be provided at the exit of the lay-by, after the exit "keep clear" zone required for trading vehicular access.

Figure 3 a & b: Type A lay-by with trading facility

Figure 3 a and b Type A lay by with trading facility

4.1.6 Bus Lay-bys

For bus lay-bys, raised bus boarding areas and shelters are to be provided in accordance with the guidance in 'Inclusive Mobility'.

A drop off point should be provided in bus lay-bys in rural areas where no other drop off facility or connecting footway is available. The drop off point should be placed at the exit of the lay-by and include a dropped kerb, but no marked parking bay.

Appropriate access to and from the bus stop should be provided. Opposing bus lay-bys, linked by a suitable crossing facility where feasible, shall be applied on a right-left stagger.

Figure 4: Bus lay-by

Figure 4 Bus lay by

4.1.7 Bus Stops (In-line)

Bus shelters are to be designed in accordance with 'Inclusive Mobility'. Designers are to provide for current bus sizes and manoeuvrability. It is recognised that bus dimensions may change in the future, therefore some extra space should be allowed. This is particularly relevant where the bus stop is located adjacent to marked parking or loading bays.

Within lit urban areas restricted to 30 miles per hour or less bus stops may be built out from the footway to allow buses to pull up parallel with the kerb and resume travel without requiring to wait for a gap in passing traffic. The buildout should be sited such that the bus shelter and waiting passengers do not obstruct passing pedestrian flows. Bus passengers and bus drivers must have an unobstructed view of one another. A raised bus boarder is to be provided.

Appropriate access to and from bus stops should be provided. Opposing bus stops, linked by a suitable crossing facility, shall be applied on a right-left stagger.

For roads with a speed limit of ≤ 40 miles per hour, raised bus boarding areas are to be provided in accordance with the guidance in 'Inclusive Mobility'. On roads with a speed limit of > 40 miles per hour bus stops are to be located within a lay-by, with raised bus boarders. Where an in-line stop already exists raised bus boarders are not to be used on roads with a speed limit > 40 miles per hour.

Figure 5: Standard footway and bus stop

Figure 5 Standard Footway and bus stop

4.1.8 Controlled Pedestrian Crossings

TA 68/96 (DMRB 8.5.1) covers the design of pedestrian crossings. Signal controlled pedestrian crossings are required by disabled people to cross busy roads. This is particularly the case for visually impaired people. Red coloured tactile paving must be provided to help visually impaired people to find controlled crossing points. Illumination levels on pedestrian crossings should also be carefully considered.

When providing controlled pedestrian crossings, audible signals and tactile indicators (rotating knurled cones for example) are to be provided, in addition to visual signals. These features are also to be provided at pedestrian facilities at signalised junctions. It may not always be practical to provide audible signals, such as where two crossings are close together, but tactile indicators must always be provided. The technology used in puffin crossings has a number of advantages for pedestrians over the older pelican type crossing including on-crossing detection which senses when pedestrians are using the crossing and extends the green time for pedestrians and holds the signals for drivers at red. For these reasons all new controlled crossings with pedestrian facilities shall include the features of puffin crossings further to the guidance in 'Inclusive Mobility' and the 'Puffin Crossing Good Practice Guide' (Department for Transport, 2006). These documents contain detailed advice on the design and publicity of puffin crossings.

Transport Scotland can no longer support the use of zebra crossings because they are unsuitable for visually impaired pedestrians.

Figure 6: Controlled pedestrian crossing

Figure 6 Controlled pedestrian crossing

4.1.9 Dropped Kerbs

Dropped kerbs must be used at all pedestrian crossings (controlled or uncontrolled).

All new crossing installations must be flush with the adjacent road surface, the permissible tolerance being 0 to 6 millimetres.

The following dropped kerb issues are particularly important:

  • The upstand at most dropped kerbs is higher than the 6 millimetres tolerance, thus creating a significant barrier to access;
  • When retrofitting a dropped crossing into an existing footway where the installation of a flush dropped kerb has the potential to create an area of standing water, additional gullies may be required;
  • The use of single transition kerbs at crossings is common practice but this results in most footways exceeding maximum recommended gradients. HD 39/01 (DMRB 7.2.5) deals with design of footways and states the maximum gradient should be 8 per cent (1 in 12) in extreme circumstances. All dropped kerbs at crossing installations are to be dropped over two transition kerb lengths to achieve the required approach gradients unless the layout of the crossing provides an alternative way of achieving this.

Figure 7 a: Flush dropped kerb (inset controlled crossing)

Figure 7 a Flush dropeed kerb inset controlled crossing

Figure 7b: Flush dropped kerb (uncontrolled crossing away from a junction)

Figure 7b Flush dropped kerb uncontrolled crossing away from a junction

4.1.10 Footway Width

The minimum width of a footway is to be 2000 millimetres in normal circumstances, since this width allows two wheelchair users to pass.

In existing constrained environments and where obstacles are unavoidable, an absolute minimum width of 1500 millimetres may be used without the requirement of a Departure from Standard.

Figure 8: Footway dimensions

Figure 8 Footway dimensions

4.1.11 Headroom

TD 36/93 (DMRB 6.3.1) sets a minimum headroom of 2600 millimetres, and 2300 millimetres for short obstructions. Trees and bushes close to or overhanging a footway should be cut further back to allow for growth.

4.1.12 Crossfall

Steep cross-falls are problematic for wheelchair users and where the footway falls towards the road this can be potentially dangerous. The maximum crossfall on a footway is to be 2.5 per cent (1 in 40).

4.1.13 Longitudinal Gradients

It is generally recognised by all guidance on this subject that steep gradients pose problems for people with mobility impairments, including wheelchair users. Steeper gradients require more effort to ascend and more care to descend.

HD 39/01 recommends a maximum gradient of 5 per cent (1 in 20). This concurs with the advice in 'Inclusive Mobility' and most other guidance on the subject.

TD 36/93 (DMRB 6.3.1) deals with underpasses for pedestrians and cyclists, however, longitudinal gradients here should also be a maximum of 5 per cent (1 in 20).

Gradients above the maximum 5 per cent are to be designed as ramps, as described in Section 4.3.

Figure 9: Maximum longitudinal gradient

Figure 9 Maximum longitudinal gradient

4.1.14 Landings (Rest Points)

The steeper the gradient the shorter the length of slope that people with mobility impairments can negotiate with ease. Level landings on a route with gradients allow people to rest comfortably and safely.

A gradient of 5 per cent (1 in 20) or greater must be considered as a ramp, which requires level landings at regular intervals (the steeper the ramp the shorter the distance between landings). Handrails must be provided on both sides. For the design of steps and ramps, refer to Section 4.3.

The Scottish building regulations acknowledge that gradients of between 2 per cent (1 in 50) and 5 per cent (1 in 20) can pose a barrier to some people with mobility impairments. There is a requirement within the regulations that level rest points must be provided at intervals proportional to the gradient on the approach to a building entrance with a maximum rise of 500 millimetres between rest points.

Level rest points should be provided on footways with gradients between 2 and 5 per cent.

Figure 10: Landings

Figure 10 Landings

4.1.15 Shared Pedestrian/Cycle Routes

'Cycling by Design' (Scottish Government, 2010) describes the design of shared pedestrian/cycle routes. It is acknowledged that there can be conflict between different user groups and shared use facilities should be restricted to where the flows of cyclists or pedestrians are low.

Research by Guide Dogs and the Royal National Institute for the Blind identifies shared surfaces as posing a threat to vulnerable road users, including those with physical, sensory or cognitive impairments.

As a guide, the use of shared pedestrian/cycle routes are not recommended in congested urban environments where pedestrian and cycle use is high. However, the decision to provide a shared facility should always involve considering the views of the local Access Panel and groups representing visually impaired people.

4.1.16 Surfacing Materials

Both HD 39/01 and 'Inclusive Mobility' concur on the need for smooth, slip resistant footway surfaces. There is also agreement on what types of surfaces achieve this aim: these include concrete flags and paviours. HD 39/01 describes ways of ensuring the long-term integrity of footways, such as avoiding damage by tree roots and locating services under the verge rather than the footway where possible. The slip resistance of the footway surface must meet the requirements of HD 39/01.

4.2 Junctions

4.2.1 Introduction

This section describes the key inclusive design elements in the design of junctions.

4.2.2 Signalised Junctions

TD 50/04 (DMRB 6.2.3) provides guidance on roads users' specific requirements when signal control is being considered. The extent of pedestrian crossing movements, cyclist, equestrian usage, and bus movements should be determined and the provision of specific measures included unless site specific considerations dictate otherwise.

The following are to be provided as a minimum at all signalised junctions:

  • TD 50/04 refers to 'Guidance on the Use of Tactile Paving Surfaces' (Department for Transport, 2005) for different types of pedestrian crossing points;
  • TD 50/04 states that where pedestrians are expected to cross arms of a junction, tactile surfaces and dropped kerbs shall be provided - this is a mandatory requirement of the DMRB;
  • TD 50/04 states tactile paving, tactile rotating cones, audible signals, and dropped kerbs are all mobility aids designed to assist disabled people at the crossing.

The features of puffin type crossings described in Section 4.1.8 are also to be provided at pedestrian facilities at signalised junctions.

Figure 11: Signalised junction

Figure 11 Signalised junction

4.2.3 Major/Minor Priority Junctions

TD 42/95 (DMRB 6.2.6) provides guidance on roads users' specific requirements in designing major/minor priority junctions. The high speed nature of rural roads is such that specific facilities may be required at some locations in order to ensure the safe passage of specific road users through the junction. This is equally true at some urban sites where the junctions may be used intensively by all types of road user.

The following should be provided as a minimum at all major/minor priority junctions where pedestrian movements are expected.

Desirable Crossing Arrangement

TD 42/95 highlights that at-grade pedestrian crossing points on the minor road should be a minimum of 15 metres back from the "give way" line, and should be sited so as to reduce to a minimum the width to be crossed by pedestrians provided they do not involve excessive detours from their desired paths. Central refuges are to be used but not on major roads in a rural situation. Where pedestrians cross the minor arm of a junction, tactile surfaces and dropped kerbs are to be provided. Refuges are to be at least 1500 millimetres wide to protect wheelchair users and parents with push chairs when crossing the road. Tactile surfaces and dropped kerbs are to be provided on refuges. Where a traffic separation island is used as a crossing point by pedestrians it must also be equipped with dropped kerbs and tactile surfaces.

Figure 12: Desirable crossing arrangement

Figure 12 Desirable crossing arrangement

Practical Crossing Arrangement

TD 42/95 highlights that the requirements of pedestrians should be carefully considered in the design and choice of major/minor priority junctions. Although it is preferable to provide separate pedestrian routes away from the junction, as described above, this is rarely practical, particularly in the urban environment.

In such cases, uncontrolled crossings are to be provided on the pedestrian desire line across the minor arm of a junction with the appropriate use of tactile blister paving, dropped kerbs, and a central refuge on the minor road.

Figure 13: Practical crossing arrangement

Figure 13 Practical crossing arrangement

Alternative Crossing Facilities at Major/Minor Priority Junctions

The following alternative facilities should also be considered for higher trafficked situations:

  • Displaced controlled pedestrian crossing;
  • Subway or footbridge.

4.2.4 Roundabouts

TD 16/07 (DMRB 6.2.3) highlights roads user specific requirements in relation to roundabout design. Separate pedestrian routes with crossings away from the flared entries to roundabouts are preferable where road widths are less and traffic movements are more predictable. Roundabouts feature continuous flows and can be particularly difficult for pedestrians to negotiate, particularly those with mobility impairments. For this reason, uncontrolled crossings at roundabouts are not recommended and an alternative crossing facility should be considered.

Alternative Crossing Facilities at Roundabouts

The following facilities should be considered at roundabouts:

  • Displaced controlled pedestrian crossing;
  • Signalisation of the roundabout, with pedestrian facilities;
  • Subway or footbridge.

4.2.5 Vehicle Access to the Road (Vehicle Footway Crossovers)

Vehicle Footway Crossovers - Domestic

At lightly trafficked footway crossovers, such as where the access to a domestic driveway crosses a footway, a minimum 25 millimetres upstand should be provided between the carriageway and the vehicle crossover.

Figure 14: Vehicle footway crossover (domestic)

Figure 14 Vehicle footway crossover domestic

Vehicle Footway Crossovers - Commercial

Where the traffic flow is sufficiently high, a vehicle crossover, or vehicle access should be treated in a similar manner to an uncontrolled crossing at a side road and tactile blister paving should be provided. A traffic calming measure in the form of a ramped table should also be provided within the entrance highlighting to vehicles that this is a footway crossing. In addition to the above, where the crossover surface is being replaced with another surface, it is helpful if the replacement surface provides a contrast in colour and tone with the footway.

Figure 15: Vehicle footway crossover (light commercial)

Figure 15 Vehicle footway crossover light commercial

4.3 Steps and Ramps

4.3.1 Introduction

This section describes the key inclusive design elements in the design of steps and ramps which are normally associated with access to bridges and underpasses or when negotiating difficult topography, particularly in the urban environment.

4.3.2 Ramps

Gradients of 5 per cent (1 in 20) or greater are to be considered as ramps. The steeper the ramp the shorter the distance should be between landings. Recommended distances between landings for different ramp gradients given in both BS 8300:2009 and 'Inclusive Mobility' are as Table 1 below (this table may be interpolated):

Table 1: Ramp gradients and lengths

Gradient

Maximum Length

Maximum Rise

1 in 20 (5 per cent)

10 metres

500 millimetres

1 in 15 (7 per cent)

5 metres

333 millimetres

1 in 12 (8 per cent)

2 metres

166 millimetres

More than 1 in 12 (> 8 per cent)

Not permitted

Not permitted

Above a certain length, even with the appropriate gradient and number of rest points, a ramp is a barrier to independence for many people with mobility impairments. BS 8300 recommends that no series of ramps should have a rise greater than 2 metres, unless there is an alternative route such as a lift. However, BS 8300 is targeted at buildings and their approaches and it would not be reasonable or practical to provide lifts at a large proportion of locations on the road network. 'Inclusive Mobility' quotes examples of acceptable ramp lengths used in the rail environment. However, the ramps in this environment are normally under cover and there is often assistance available at most railway stations. The BS 8300 standards for ramps set the only dimensions which stand up to scientific scrutiny for self propelled wheelchair users.

Gradients of 1 in 20 (5 per cent) or greater are to be considered as ramps and all ramps must meet the criteria described in 'Inclusive Mobility', which requires level landings (at least 1500 millimetres long) at regular intervals (the steeper the ramp the shorter the distance between landings). Handrails must be provided on both sides. Steps must always be provided as an alternative to a ramp, refer to the following sections on steps for more details.

Figure 16: Ramp

Figure 16 Ramp

4.3.3 Steps - Dimensions

A large proportion of disabled people find it easier and safer to use well designed conventional steps rather than a ramp. It is now well recognised that stepped ramps are a compromise of different requirements and do not work well for anyone; this feature is common on footbridges built in the 1970s and 1980s. BD 29/04 (DMRB 2.2.8) on the design criteria for footbridges recognises the desire to provide steps as an alternative to a ramp. There is a consensus between all the documents including BD 29/04 that open risers are not acceptable. Steps can be a hazard for people with visual impairments, and small numbers of steps can be more difficult to identify than full flights. Corduroy warning surface must be used to warn of a flight of steps and step nosings must be highlighted from the steps and risers.

The maximum number of steps in a flight in normal circumstances should be no more than 12 and the minimum number should be 3 steps. Where the change in level is less than 260mm, a ramp should be provided instead of a single step. The preferred step going is 300 millimetres and the rise should be between 150 millimetres and 170 millimetres. Level landings should be provided between successive flights of steps, at least 1200 millimetres long, preferably 1800 millimetres, and across the full width of the steps.

Figure 17: Steps - dimensions

Figure 17 Steps dimensions

4.3.4 Steps - Tapered Risers

Tapered risers, i.e. where the rise of a step is not parallel to the rise of the step above or below, is especially dangerous for visually impaired people. This feature is ruled out by BD 29/04 and the Scottish building regulations.

4.3.5 Steps - Nosings

'Inclusive Mobility' and other good practice documents recommend step nosings should be highlighted with a 50-60 millimetres deep tonally contrasting strip on both the tread and the riser to ensure this important feature is noticeable when ascending and descending a flight of steps. Light levels are often lower than desirable in the pedestrian environment and step nosings are important features for all pedestrians but especially important for people with visual impairments.

4.3.6 Handrails

'Inclusive Mobility', TD 36/93 and all other guidance documents, including BS 8300 recognise the need for handrails on both sides of ramps and stairs. There is also a consensus on a round or oval gripping profile as being the most appropriate and on the need to extend handrails past the top and bottom of a flight.

Handrails are very important. People with mobility impairments use handrails for support while people with visual impairments use the rails as a guide to where they have reached on a flight. People with mobility impairments often have a weakness on one side of their body and they may use a stick or crutch in one hand. Therefore, they can only grip a rail with the same hand whether ascending or descending. Extending the handrails past the top and bottom of a flight can help to indicate the end of a flight to visually impaired people and also helps people with mobility impairments by allowing them to grip the rail before ascending or descending. Handrails should contrast in tone with their background to assist visually impaired people, and they should be comfortable to grasp in hot or cold weather.

The height of handrails is clearly established in TD 36/93, 'Inclusive Mobility' and the Scottish building regulations. 'Inclusive Mobility' also recommends providing a lower handrail for children and people with reduced stature. This additional rail will be particularly important on routes to primary schools.

Figure 18: Steps - handrails

Figure 18 Steps handrails

4.4 Tactile Surfaces

4.4.1 Introduction

This section describes the design functions of the different types of tactile paving to assist visually impaired pedestrians using the road network.

4.4.2 Tactile Surfaces

There are a variety of different tactile surfaces used in countries across the world to convey information to visually impaired people in the pedestrian environment and the methodologies for using these surfaces vary. In the UK there are six recognised on-street tactile surfaces. These surfaces must be used consistently in order to provide effective warning, way finding and information clues to visually impaired people.

The authoritative source of information on the use of tactile surfaces in the UK is the Department for Transport publication 'Guidance on the Use of Tactile Paving Surfaces'.

The most frequently used tactile surface is blister paving. There is a common misconception that this surface is used to indicate a safe place to cross a road. However, the principal message this surface indicates is that there is a lack of a kerb height change between the road and the footway, for example where the kerb has been dropped flush with the road at a pedestrian crossing. A kerb upstand between the road and the footway is an important marker to visually impaired people, since it delineates between the road and the footway where it is safe to walk. A kerb can also convey the direction the footway is taking - for this reason it is important at dropped kerbs that the tactile paving is orientated in exactly the direction of crossing (tactile paving slabs must therefore be cut where they abut kerbs around the corner radius of a junction - refer to Figure 13). At controlled crossing points the secondary message that tactile blister paving conveys to visually impaired people is the location of the crossing control pole. It is important that visually impaired people can find and use controlled crossings, since these are the safest place for vulnerable road users to cross the road.

Tactile paving should contrast tonally with the surrounding paving materials. For safety reasons red coloured tactile blister paving is reserved for controlled crossings.

Metal studs have been used to create the blister profile in a number of city centres. These studs have proved to be slippery when wet and must not be used. It is also important to ensure that the top surface of the blister is flattened, as a round surface can be uncomfortable and increases the risk of slipping or tripping.

Figure 19: Blister surface

Figure 19 Blister surface

The other five surfaces are as follows. These tactile profiles can be created in a variety of different materials, including concrete, natural stone and rubber, for a variety of situations. The material chosen must have a similar slip resistance to the surrounding paving materials to avoid creating a trip hazard.

  • Corduroy tactile warning surfaces - this surface is used to warn visually impaired people in advance of hazards in the pedestrian environment such as steps or junctions with shared pedestrian/cycle routes.

Figure 20: Corduroy hazard warning surface

Figure 20 Corduroy hazard warning surface

  • Cycletrack surface - this surface is used to delineate between the pedestrian and cyclists sides of a segregated route at salient points along the route.

    'Cycling by Design' describes the design of shared pedestrian/cycle routes. It acknowledges that there can be conflict between users - refer to Section 4.1.15.

Figure 21: Shared cycletrack/footway surface and central delineator strip

Figure 21 Shared cycletrack footway surface and central delineator strip

  • Guidance surface - this flat topped ribbed profile is intended to define a safe route through wide, open pedestrian areas, such as a town square, with few orientation clues for visually impaired people. There should be no need for this surface in new well designed environments, since visual and nonS-visual orientation clues can be integrated into the design of the public realm. However, local Access Panels and organisations representing visually impaired people may identify a need for the use of this surface to mitigate wayfinding problems in an existing environment. Further advice is contained within 'Designing Streets' (Scottish Government, 2010).

Figure 22: Guidance path surface

Figure 22 Guidance path surface

  • On-street platform edge - this lozenge shaped profile is intended for use on raised on-street tram platforms to orientate visually impaired people and warn of the drop on to the rails.

Figure 23: Platform edge (on-street) warning surface

Figure 23 Platform edge on street warning surface

  • Information surface - this rubber surface is used to highlight key features in pedestrian environments, such as telephone boxes and cash machines, which visually impaired people may have difficulty locating.

Figure 24: Information surface

Figure 24 Information surface

4.5 Street Furniture/Ancillary Equipment

4.5.1 Introduction

This section describes the key inclusive design elements in the design of street furniture and ancillary equipment.

4.5.2 Street Furniture

There is a wide range of different types of street furniture, from lighting columns and litterbins to wheeled bins, bollards and sign poles. Most street furniture is necessary but often items of furniture such as lighting columns and sign poles are left behind long after they become redundant. Badly sited furniture is an obstruction to people with mobility impairments and people with visual impairments. Free-standing items, such as bollards, are a particular problem for visually impaired people.

Badly designed street furniture can also pose a hazard to visually impaired people. Furniture lower than 1000 millimetres such as benches without backrests and low bollards are not in most adults normal line of sight. In addition, all street furniture should be detectable at ground level with a long cane. Projecting litterbins fixed to lighting columns and the glazed side walls of cantilevered bus shelters are obvious examples of street furniture which break this rule.

Visually impaired people who receive mobility training, including guide dog and long cane users, are trained to walk in the middle of a footway since there are normally less obstructions in this zone. Visually impaired people move towards the kerb edge or the back of the footway when looking for a crossing or building entrance respectively. Guide dog users and people with mobility impairments, particularly wheelchair users, require a minimum width of footway to allow them to move easily along a route. Refer to Section 4.1.10 for the minimum footway width between obstructions.

'Inclusive Mobility' describes how items of street furniture should be grouped together where possible to assist visually impaired people to identify the potential hazard. This document also describes how colour, including the use of coloured banding, can be used to help avoid collisions with street furniture.

For visually impaired pedestrians relying on residual vision, it is essential to ensure that the colour of street furniture contrasts with its surroundings. Colours which appear to be different from one another in colour (chroma) can be very similar tonally (e.g. green and brown) and therefore do not give sufficient contrast. Contrast is the visual perception of one element when viewed against another and is indicated by the difference in light reflectance between two surfaces. It is generally recognised that 30 points of difference in light reflectance between surfaces should give adequate contrast to be noticeable to a large proportion of partially sighted people. However, the research on this subject was undertaken inside buildings where light levels can be more easily controlled. The level of light shinning on a surface has a large influence on the visual perception of contrast, too low or too high a light level can greatly reduce the perception of contrast between colours. Light levels outdoors obviously vary greatly. Therefore, higher differences in light reflectance value than 30 points would be preferable.

To specify suitable colours for new schemes designers should establish the light reflectance value of the street furniture with the manufacturer. As a rule of thumb, for existing street furniture, an adequate contrast will show up on a black and white photograph or a photocopy of a colour photograph, poor contrast will show up as shades of grey. For further information on the use of colour reference should be made to 'Colour, Contrast & Perception - Design Guidance for Internal Built Environments' (University of Reading, 1997) and BS 8300.

All unnecessary and redundant street furniture should be removed from footways as part of routine maintenance. All necessary street furniture should be at least 1000 millimetres high and should be grouped together at the back of the footway where possible and out of the main pedestrian flow. Street furniture which is in or close to the pedestrian flow and particularly freestanding furniture in this zone must contrast tonally with its surroundings.

In most circumstances guardrails are not specifically an accessibility feature and railings can be a hindrance to disabled people. These rails can narrow the pedestrian route and can present a hazard to visually impaired people. Wheelchair users, children and people of short stature can be hidden behind street furniture which emphasises the importance of drivers being able to see through railings. For these reasons there must be 2000 millimetres between parallel guardrails and guardrails should be at least 1000 millimetres and ideally 1200 millimetres above ground level. Guardrails must extend to within at least 200 millimetres of the ground, to assist visually impaired people to detect this feature with a long cane.

'Inclusive Mobility' states that guardrails should contrast in tone with their surroundings and for this reason simple galvanised or black painted rails would be unacceptable. However, Transport Scotland considers that finishing guardrailing in a contrasting colour to their surroundings would be aesthetically unacceptable in many settings. Therefore, provided guardrails are sited appropriately only the ends of the guardrailing should be highlighted where they project into the pedestrian flow. The ends of the railings must be highlighted with two 150 millimetre deep bands which contrast tonally with the colour of the railing. By grouping other furniture with a larger profile, such as fixed litterbins, at the ends of guardrailing, the collision hazard of the ends of railings can be minimised.

Figure 25: Street furniture

Figure 25 Street furniture

4.5.3 Designing for Tonal Contrast

Existing street furniture must also provide sufficient tonal contrast and the application of a tonally contrasting treatment will be required. This can be achieved, as a minimum, using 150 millimetre deep colour bands which contrast in tone with the colour of the furniture. Bollards and low furniture must have a single band at 1000 millimetres above ground level. Taller items of furniture such as bus shelters and lighting columns must be highlighted with two bands, one at 900 - 1000 millimetres and the other at 1400 - 1600 millimetres measured from ground level to the top of the band. In the case of glazed screens, such as those found on bus shelters, two coloured bands should also be provided. The colour chosen for the highlighting on glazing should contrast with the background against which it will be viewed.

In the design of new schemes or for the installation of new items of street furniture, tonal contrast must be a key element of the aesthetic design of materials and finishes. Integrated into the design process, a broader range of aesthetically pleasing design can be achieved. Designers should not be restricted to using the 150mm banding which is the minimum vertical dimension required. Where appropriate for example, the banding could take the form of a logo or emblem such as could be applied to a glass screen at a bus stop.

4.5.4 Seating

Many ambulant disabled people cannot walk for more than 50 metres before taking a rest and suitable seating at regular intervals is a particularly important feature in the pedestrian environment. Seats with backrests should be provided at regular intervals along well used pedestrian routes. Seating should generally be 450 - 480mm high, a height most people can rise from, but at bus stops and other locations where people wait for a short period of time "perch" seats can be provided. 'Inclusive Mobility' recommends a height of 580mm for this type of seating. At least a proportion of seating in a group should be fitted with armrests to assist in rising from the seat. However, to allow wheelchair users to transfer on to fixed seating, not all seats should have armrests, i.e. there should be no armrest on the end of a row of seats. A space should be kept clear next to fixed seating to accommodate wheelchair users.

4.5.5 Signage

The specification of road signs for drivers is explained within the 'Traffic Signs Manual' (Department for Transport, 2006) and the Traffic Signs Regulations and General Directions 2002 (TSRGD). 'Inclusive Mobility' contains more information on the design of signage for pedestrians. This information is based on the 'Sign Design Guide', (Sign Design Society) and guidance from North America. The principles of clear signage are explained in the document, including the use of colour to highlight the sign from its background and to highlight the text on the sign and the need for upper and lower case lettering rather than all capitals. To enable a sign to be located on both light and dark backgrounds, a border can be incorporated on the sign, rather than changing the colour of the sign board. The guidance also includes a table of text heights suitable for different viewing distances.

Only around 5 per cent of visually impaired people have no sight at all. The vast majority have some residual vision, and may be able to distinguish colours, or shades of light and dark. By making a sign clear and easy to read for a visually impaired person it will make the sign clear and easy to read for most people.

Sign poles and cantilevered signs can present a barrier and a hazard to disabled people and the points made earlier concerning the position of street furniture and minimum footway widths must be applied.

The lack of the minimum distance between poles on double pole signs, and the lack of colour contrast to highlight sign poles is an important issue for partially sighted people.

Where signage aimed at pedestrians is not covered by the 'Traffic Signs Manual' or TSRGD, signage should follow the guidance in 'Inclusive Mobility' and the 'Sign Design Guide'. Authorisation will be required for non-prescribed signs.

4.5.6 Lighting

BS 5489:2003 is the code of practice for road lighting. The illumination of the pedestrian environment is often neglected. 'Inclusive Mobility' describes the recommendations of BS 5489 and includes a table of light levels for different areas.

Lighting columns can obstruct the footway and present a hazard to visually impaired people. Therefore, columns must be located outwith the footway or if necessary at the back of the footway. In existing locations, columns should be sited consistently either at the back or front of the footway. To reduce clutter at street level in urban areas, new light fittings should, where practical, be fixed to buildings.

All new and replacement lighting schemes for pedestrian areas must meet the criteria described in 'Inclusive Mobility', in addition to BS 5489.

4.5.7 Rest Areas

There are a number of rest areas on the road network where facilities, such as parking, picnic areas and toilets are provided. The design of new facilities and upkeep of existing facilities must consider the needs of disabled people, alongside the needs of all other users, to meet the commitment to disability equality.

TD 69/07 (DMRB 6.3.3) describes rest areas as all sites on motorways or all-purpose trunk roads that provide parking and an associated picnic area. They may also provide some, but not all, of the facilities normally associated with a service area.

In addition to the inclusive design of the road infrastructure described in this Guide, the design of all features contained within the rest area site should adhere to inclusive design principles.

4.5.8 Parking

'Inclusive Mobility' gives clear guidance on the proportion of parking spaces which should be provided for vehicles carrying disabled people and on the design of these spaces. Accessible parking spaces should be sited on level areas with little or no cross-fall, as close as practicable to any amenities. Signage and street furniture should be kept clear of parking spaces and placed at the rear of the surrounding footway. Road markings must be in accordance with TSRGD - yellow road markings may be used for off-street parking spaces.

Figure 26 a: Accessible off-street parking spaces (e.g. in rest area)

Figure 26a Accessible off-street parking spaces eg in rest area

Figure 26 b: Accessible on-street parallel parking space (e.g. in town centre)

Figure 26b Accessible on-street parallel parking space eg in town centre

4.5.9 Toilets

One of the most common forms of disability is incontinence and a lack of suitable toilet facilities prevents many disabled people and their families making journeys. Therefore, wherever possible rest areas should include toilet facilities. If there is only space to accommodate one toilet it should be a unisex accessible toilet. The accessible toilet should be designed to the standard set out in BS 8300. The provision of "Changing Places" toilets should be considered for larger rest and service areas. These facilities are designed to accommodate disabled adults who require assistance in using the toilet and those who require assistance to change. See http://www.changing-places.org/.

Figure 27: Accessible toilet - plan

Figure 27 Accessible toilet plan

Figure 28: Accessible toilet - elevation

Figure 28 Accessible toilet elevation

4.5.10 Emergency Telephones

It is important that everyone must be able to reach and use an emergency telephone. In this regard, the location of the phone is just as important as the design of the installation.

A level hard standing/plinth of 1800 x 1800 millimetres minimum (1500 x 1500 millimetres absolute minimum) must be provided adjacent to the phone installation to allow wheelchair users to manoeuvre up to the phone and to turn around before returning to their vehicle. In addition, a person may have a weakness on one side and therefore being able to turn round to use the phone is essential. A flush dropped kerb arrangement should also be provided to allow access to the plinth from the carriageway. A raised kerb should be provided along the exposed edge of the plinth where the plinth is raised above the ground or where the ground falls away, such as when an emergency phone is located on the edge of an embankment.

The phone controls should be in the range of 900 and 1100 millimetres in height from the ground providing a reasonable level of access for most users.

The following drawings show the layout of the emergency phone located within an emergency lay-by and on a motorway with hard shoulder, and where TD 19/06 (DMRB 2.2.8) describes the arrangement for accommodating an emergency telephone where a safety barrier is present.

Figure 29: Emergency telephone in emergency lay-by (no barrier or footway)

Figure 29 Emergency telephone in emergency lay-by no barrier or footway

Figure 30: Emergency telephone on hard shoulder (no barrier)

Figure 30 Emergency telephone on hard shoulder no barrier

Figure 31: Accommodating emergency telephone at verge safety barrier

Figure 31 Accommodating emergency telephone at verge safety barrier