4 ACCESSIBILITY OF TRANSPORT SERVICES
Let us now concentrate on the physical accessibility of vehicles and infrastructure. There is often a tendency to regard a transport system that can be used by someone in a wheelchair as accessible, and one that cannot as not accessible. Whether the person in a wheelchair can use the system without assistance is often not defined. This is a gross over-simplification; impairments can be locomotive (walking difficulties, wheelchair user), tactile (grasping, holding or touching), sensory (visual, hearing or speaking problems), cognitive and other (ECMT, 1986). These impairments limit the abilities of the individual in some respect, and we all have some physical or mental limitations.
A transport system is accessible to an individual with a set of impairments if, by good design and appropriate operation, that system can be used by the individual without the need for the individual to use any of the functions that their impairment prevents them using. Good design can reduce the physical requirements involved in using a system to a level that is possible. For example, a person with impaired ability to walk and climb may well be able to use a bus if it has low steps, good handrails and adequate seat space, but be totally unable to use a bus where the entrance has steep steps and no handrails. A sub-set of this is that the system is accessible if the individual has assistance to perform the impaired functions that are necessary for the use of the system.
The use of a wheelchair enables a person whose ability to walk is impaired to move about, provided the infrastructure is suitable. In practice, many people in wheelchairs are able to move further and faster than people who can walk, but whose walking is impaired by respiratory or circulatory disease, or by arthritis. But this advantage for the person in a wheelchair is nullified by a kerb, a flight of stairs or a patch of muddy ground.
To make a transport system accessible, the designer must know the functions of the potential users that are impaired, understand what those impairments prevent the passenger from doing, and design the system so that to use the system the passenger does not need to do things that are impossible. Because different people have different impairments, transport systems need different features to make them accessible to different groups of users.
Thus, the large group of ambulant disabled people who can walk, but with difficulty, can climb steps if they are shallow and have good handrails, and who need handholds to help balance, need vehicles or infrastructure designed to good standards to be useable. But these standards also make the vehicles or infrastructure easier and safer for able bodied people to use. People with impaired vision are helped by good colour contrasts, the use of bright colours and well-lit signing using large clear letters or symbols. Again, these features help everybody. People in wheelchairs need ramps in place of steps or kerbs, good surfaces, lifts for large height changes. These features can help others, certainly help other people with wheeled luggage (prams, baby buggies, shopping trolleys) and can help the more impaired of ambulant disabled people.
Once the design of a system makes it physically accessible to its users, it is necessary for the system operator to ensure that its users know of its existence, have the information they need to be able to use it, and are not prevented from using it by operating practices, rules or some lack of security that undermines the users’ confidence in the system. The barriers of information and confidence can be just as great as those of high steps, steep gradients or long walks.
However much effort is put into making systems accessible, they will never be useable by the whole population. There will be people who are housebound or chair- or bed-fast, people with behavioural problems, people who need constant assistance. It is not realistic to expect mass transport systems to be useable independently by people so severely impaired that they cannot leave their house without assistance. What it is reasonable to expect, and what is becoming the case for new transport systems, is that people should not be prevented from using a system only because of deficiencies of physical design or of operating procedures.