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system architecture could have users each using a small receiver with a headphone of standardised design.
10.2 Physical Environments: The Streetscape
Street layout and the position of building and public transport facilities have developed historically with different degrees of planning and regulation in different places. However, it is also only relatively recently that concerted attention has been given to the planning and design of urban environments for accessibility. It should also be noted that some of the potential hazards to blind and visually impaired people, such as large numbers of fast moving vehicles and crowded streets are relatively recent, though they predate concerns about accessibility.
Therefore, existing street layouts and building design put constraints on what can be achieved concerning accessibility, though there are moves to try to ameliorate previous inaccessible design decisions. Concerns for maintaining the character of an area and the practice of ‘listing’ some buildings as being of particular historical interest with consequent limitations to changes that can be made to them may also put constraints on what can be achieved with regards to accessibility. It is to be hoped that all future streetscape developments will incorporate accessibility considerations.
Another factor that has a significant impact on accessibility is the diversity of vehicles and people using a streetscape. The vehicle types include bicycles, individual mobility carriers, mopeds, cars and trucks, whilst the diversity of human users includes pedestrians, wheelchair users, blind people using mobility devices, people (both disabled and non-disabled) accompanied by children and people pushing children in pushchairs. A particular problem is the fact that in many countries cars and other motorised vehicles sometimes park on the pavement. This can cause a hazard for blind and visually impaired people and can also have the effect of blocking or partially blocking the pavement, particularly for wheelchair users. In areas where there is a deficiency of cycle lanes, cyclists may also cycle on pavements and this could also cause a hazard for blind and visually impaired people. In some countries there are shared paths for cyclists and pedestrians that do not have any delineation between the part of the path for cyclists and that for pedestrians. This could be a hazard for blind and visually impaired people, as well as being generally unpopular with pedestrians and cycling groups.
10.2.1 Pavements and Pathways
Pavements and pathways allow people to move around towns and access facilities, such as shops, doctors, dentists and health centres, public transport, housing and leisure and recreation facilities. Good layout should include features such as ramps instead of steps, lowered curbs and direct routes between facilities with an avoidance of road crossings.
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The following factors are important for the design and maintenance of pavements and pathways:
•The surface materials used in pavements and pathways should not become slippery in wet weather. For example, blister blocks in brass or plastic become slippery hazards when wet.
•The edges of pavements and pathways should be clearly identifiable. Kerbs, clear high contrast painted lines and a change in texture can be used to give a visible and/or tactile delineation.
•Steps should be avoided and ramps used.
•Handrails should be provided, particularly on ramped walkways. They can provide guidance to visually impaired and blind people and support to some physically disabled people.
•Pavements and pathways should be regularly gritted and cleared of snow in winter. Currently in some countries, this does not happen, resulting in hazards for all pedestrians, whether or not they are disabled, but particularly for disabled and elderly people.
Tactile pavement blocks
Tactile pavement blocks are commonly used to warn of a hazard or give information about the pavement direction or purpose. There are three main functional types to indicate hazards, give directional guidance and indicate the separate pedestrian and cycle paths on a shared route, as shown in Figure 10.2.
“Corduroy” and blister blocks are used to indicate a hazard. Corduroy blocks, which are marked by a pattern of rib-shaped bars, are used to give warning of a hazard, for example, the beginning of a flight of stairs. Blister paving, where the slabs are covered with a regular pattern of small semi-spherical knobs, are used to indicate the position of a pedestrian crossing and that the pavement has a dropped kerb at the crossing.
Blocks embossed with a rounded bar pattern can be used to give directional guidance. For instance, they could be used to guide visually impaired and blind
Figure 10.2. The different types of tactile pavement blocks and their applications
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people on a safe path across a city square or lead them into and through a pedestrian precinct.
Bar-embossed blocks are used to indicate a shared pedestrian/cycle route. The bars are laid in a transverse direction to indicate the pedestrian path and parallel to the direction of travel to indicate the cyclepath route.
Note that many other groups of disabled people, as well as many non-disabled people can also benefit from both good design and good route maintenance.
10.2.2 Road Crossings
Where pedestrians are crossing a side road and moving in the direction of the main road, it should be recognised that they have right of way. Therefore, vehicles turning from the main road into the side road or the side road into the main road should be required to actively search for pedestrians waiting to cross and then stop, and wait until the pedestrians have crossed the road. Unfortunately, this does not happen currently and existing traffic behaviour privileges motorised vehicles over pedestrians and therefore may discriminate against blind and visually impaired people.
On road crossings, other than at the junctions of very quiet roads, assistive technology systems are often required to facilitate safe crossing of the road. Pedestrian crossing points are frequently indicated by belisha beacons and black and white stripped markings across the road, which are generally called zebra crossings. There should also be a lowered curb for wheelchair users, users of mobility scooters and other mobility aids and people pushing children in baby buggies. Many pedestrian crossing points also have traffic lights. These traffic lights may be integrated into the traffic control system at a road junction or solely used to regulate pedestrian or traffic flow. Pedestrians are generally able to instruct the system that they are waiting to cross, most commonly by pressing a button. However, the response time is often very slow and the time allowed for crossing may be insufficient.
Controlled crossings with traffic lights generally have visual indicators, which are normally based on large colour-coded illuminated signs. However, the icons used in different countries differ and include both green stick figures and a largeletter illuminated ‘WALK’ sign (in the appropriate language) to indicate when pedestrians can cross. These visual indicators are increasingly being supplemented by audible sounds and, less frequently by tactile indicators. In some countries there is also a visual indication of how long remains to cross or to wait to cross. However, crossings without traffic lights generally do not have indicators.
There are also issues of how blind and visually impaired people find crossings. It would therefore be useful for crossings to be equipped with either an infrared Talking Signs type system or a radio frequency identification (RFID) tag which would allow them to broadcast a signal over a moderate distance to be received by a standardised receiver and transmitted to the user either as an audio signal over a headphone or by vibration. The layout of a crossing point, as well as the immediate approach to it should be indicated by tactile pavement blocks of the blister type.
Since the nearest crossing may require pedestrians to go out of their way and pedestrians move considerably more slowly than cars and other motorised vehicles,
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there would be great benefits to all pedestrians in the development of a device which would indicate to drivers that a pedestrian was waiting to cross and require them to stop. Until this happens, some discrimination against blind and visually impaired people will occur, since they generally require a controlled crossing on even moderately busy roads, whereas sighted people are often able to cross safely at other points. In addition, it should be noted that controlled pedestrian crossings are less frequent than they should be and many roads, which are difficult or unsafe to cross, do not have a controlled crossing.
Crossovers of pavements by motorised vehicles occur where vehicles desire access to car parks, a vehicle entrance to a commercial building, a house driveway or a loading bay. Unfortunately, car and other vehicle drivers fail to recognise that pedestrians should have right of way in these circumstances and often expect pedestrians to stop for them rather than waiting for pedestrians to cross. This situation can therefore create an avoidable hazard for blind people. In some cases, points where traffic crosses the pavement are indicated by a tactile paved area. Tactile pavement indications and colour coding should always be used to indicate the presence of a possible hazard to visually impaired and blind pedestrians.
10.2.3 Bollards and Street Furniture
Bollards and other street furniture can cause a hazard, particularly to blind and visually impaired people, if not appropriately designed and sited. Bollards are used to separate traffic (often parked) from the pedestrian pathway. However, as discussed above, in many countries motorists park on the pavement and will try to circumvent bollards. If too closely spaced or too large, bollards can also prove a hazard to visually impaired and blind pedestrians and an obstacle for wheelchair users, people pushing children and cyclists trying to leave a shared path. The inappropriate positioning or design of bollards can cause a serious hazard to blind and visually impaired people that may result in painful injuries if a collision occurs. Good design (see Figure 10.3) can avoid many of these problems and should include the following:
•Minimum bollard height of 1 m.
•A bollard colour which stands out from the background.
•A band round the neck of the bollard in a contrasting colour to it.
Figure 10.3. Features of good traffic bollard design
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•A lamp to illuminate the position of the bollard at night. The illumination should be diffuse and well shaded to avoid causing problems to people with light-sensitivity.
•The Bollards should be physically separated from each other and not linked by chains or ropes.
•An appropriate spacing between bollards to obstruct cars, but not wheelchairs or baby buggies.
Street furniture is the collective term given to a variety of items found on pavements and sometimes on the road, including seating, litterbins, signposts and notice boards. All of these items are potential hazards to visually impaired and blind pedestrians. Some of the potential and avoidable hazards are illustrated in Figure 10.4. This problem can be minimised by good design, including the following:
•Good colour contrast with the dominant background streetscape colours to make street furniture more visually apparent. Bands of contrasting colour on the support poles of notice boards further aid in drawing attention to them. Colour contrasts that are visually pleasing rather than clashing should be chosen.
•Sharp edges and protrusions that can cause injuries should be avoided in the design of street furniture.
•Appropriate location and positioning, so that street furniture does not block the path and can easily be found by blind and visually impaired people who want to use it, for instance, to throw away rubbish or sit on a bench. For example, notice boards on one or two posts should have the posts at the very edge of the path to
Figure 10.4. Design to minimize the hazard of some street furniture items to the long cane user