In general terms, accessibility can be defined as ‘ease of reaching’. The accessibility objective is concerned with increasing the ability with which people in different locations, and with differing availability of transport, can reach different types of facility. The term ‘accessibility’ has been used in the past in several different, often overlapping ways, including the following:
- measurement of ease of access to the transport system itself in terms of, for example, the proportion of homes within x minutes of a bus stop or the proportion of buses which may be boarded by a wheel-chair user;
- measurement of ease of access to facilities, with the emphasis being on the provision of the facilities necessary to meet people’s needs within certain minimum travel times, distances or costs;
- measurement of the value which people place on having an option available which they might use only under unusual circumstances (such as when the car breaks down) – ‘option value’ – or even the value people place on simply the existence of an alternative which they have no real intention of using – ‘existence value’; and
- measurement of ease of participation in activities (for personal travel) or delivery of goods to their final destination (for goods travel), provided by the interaction of the transport system, the geographical pattern of economic activities, and the pattern of land use as a whole.
These aspects of accessibility are expressed as:
- to increase option values
- to reduce severance
- to improve access to the transport system