The Time Between: Continuously-defined accessibility functions for schedule-based transportation systems
Accessibility is traditionally considered to be a property of a point or region in space, and to be invariant over time (or at least over some computationally convenient time interval). How- ever, a locations accessibility can vary over time on a wide range of scales. This temporal variation is especially significant for schedule-based transportation systems. Current measures of accessibility generally reflect the accessibility only at points in time corresponding to the departures of one or more trips; accessibility between these time points remains unconsidered and undefined. Consequently, these measures are insensitive to changes in route frequency and the distribution of trip departure times. Furthermore, these approaches ignore the disutility experienced by a system user who is limited to departing or arriving at scheduled times rather than at preferred times. As a result, they systematically overestimate the accessibility experienced by users of scheduled transportation systems. We establish new methods for representing the accessibility provided by a schedule-based transportation system from a specific location as a continuously-defined accessibility function (CDAF) of desired departure time, defined for all time points. Using schedule and route information from metropolitan transit providers, we demonstrate the application of these methods to gain new insight into the accessibility provided by real-world transportation systems. Four examples are developed to represent common service types in metropolitan transit networks. The results confirm that accessibility is significantly overestimated by measuring single points and show that trip frequency is more valuable for sustained accessibility than high accessibility on individual trips.
|Date of creation:||2012|
|Date of revision:|
|Publication status:||Published in working paper|
|Contact details of provider:|| Postal: |
Phone: +01 (612) 625-6354
Fax: +01 (612) 626-7750
Web page: http://nexus.umn.edu
More information through EDIRC
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
- Ottensmann, John R. & Lindsey, Greg, 2008. "A Use-Based Measure of Accessibility to Linear Features to Predict Urban Trail Use," The Journal of Transport and Land Use, Center for Transportation Studies, University of Minnesota, vol. 1(1), pages 41-63.
- Kevin Krizek & David Levinson, 2009. "Access for Performance," Working Papers 000071, University of Minnesota: Nexus Research Group.
- S L Handy & D A Niemeier, 1997. "Measuring accessibility: an exploration of issues and alternatives," Environment and Planning A, Pion Ltd, London, vol. 29(7), pages 1175-1194, July.
When requesting a correction, please mention this item's handle: RePEc:nex:wpaper:thetimebetween. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (David Levinson)
If references are entirely missing, you can add them using this form.