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At its simplest, the ease with which one place can be reached from another. It may be measured in terms of geodetic distance, topological distance (see networks and graph theory), journey distance, journey time or monetary cost (see transport costs). The concept has been broadened in a number of ways. First general accessibility may be calculated from a single location to all other locations in the study region (cf. population potential). Second, access may be related to the geographical content of other areas in the study region: access to employment, access to markets, access to educational or health facilities etc. Third, some authors have recognized that accessibility to certain activities and facilities is modified by barriers other than geographical distance (e.g. the effects of income, ethnicity, and social class) and therefore attempt to incorporate these effects into measures of accessibility. In all of these applications accessibility is seen to combine at least three elements: the location of a place within a study region; the location within the study region of the activities to which access is being measured; and the form of the transport and communication system. It is generally argued that long-term improvements in transport and communications technology have improved accessibility (especially the access to information) and therefore reduced spatial differences in the degree to which locations are accessible (see communications, geography of; time-space convergence). (AMH) |
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