This post is part of the websurvey that all WU’s have to fill in. It explains the background of the main traditions of Accessibility modeling.
- Measures travel impediment or resistance between origin and destination, or between nodes. Travel impediment measures can include: Physical (Euclidean) distance Network distance (by mode) Travel time (by mode) Travel time (by network status—congestion, free-flow, etc.) Travel cost (variable user cost or total social cost) Service quality (e.g. public transport frequency) ( C. Curtis, J. Scheurer 2010).
- Defines catchment areas by drawing one or more travel time contours around a node, and measures the number of opportunities within each contour (jobs, employees, customers, etc) ( C. Curtis, J. Scheurer 2010).
- Defines catchment areas by measuring travel impediment on a continuous scale. ( C. Curtis, J. Scheurer 2010)
- Incorporates capacity constraints of activities and users into accessibility measure. May make use of any of the preceding three models ( C. Curtis, J. Scheurer 2010)
- Measures travel opportunities within pre-defined time constraints. ( C. Curtis, J. Scheurer 2010).
- Measures individual or societal benefits of accessibility. Indicators can include: Economic utility (to the individual, or to the community) Social or environmental benefits (e.g. social inclusion, greenhouse effects) Individual motivations of travel (by activity or travel purpose) Option and non-user benefits of transport infrastructure ( C. Curtis, J. Scheurer 2010).
- Measures centrality across entire movement networks. Networks can be represented by: the primal approach (networks are understood as intersections connected by route segments) the dual approach (networks are understood as route segments connected by intersections) ( C. Curtis, J. Scheurer 2010).
- The land-use component reflects the land-use system, consisting of the amount, quality and spatial distribution of opportunities. The transportation component describes the transport system, expressed as the disutility for an individual to cover the distance between an origin and a destination using a transport mode. The temporal component describes the availability of opportunities at different times of the day, and the time available for individuals to participate in certain activities. The individual component reflects the needs, abilities (depending on people’s physical condition, availability of travel modes, etc.) and opportunities (depending on people’s income, travel budget, educational level, etc.) of individuals. See Karst Geurs (2010) Accessibility: an academic perspective, presented at Oporto.