A Maximum Entropy-least Squares Estimator for Elastic Origin-Destination Trip Matrix Estimation

In transportation subnetwork-supernetwork analysis, it is well known that the origin-destination (O-D) flow table of a subnetwork is not only determined by trip generation and distribution, but also by traffic routing and diversion, due to the existence of internal-external, external-internal and external-external flows. This result indicates the variable nature of subnetwork O-D flows. This paper discusses an elastic O-D flow table estimation problem for subnetwork analysis. The underlying assumption is that each cell of the subnetwork O-D flow table contains an elastic demand function rather than a fixed demand rate and the demand function can capture all traffic diversion effect under various network changes. The authors propose a combined maximum entropy-least squares (ME-LS) estimator, by which O-D flows are distributed over the subnetwork so as to maximize the trip distribution entropy, while demand function parameters are estimated for achieving the least sum of squared estimation errors. While the estimator is powered by the classic convex combination algorithm, computational difficulties emerge within the algorithm implementation until the authors incorporate partial optimality conditions and a column generation procedure into the algorithmic framework. Numerical results from applying the combined estimator to a couple of subnetwork examples show that an elastic O-D flow table, when used as input for subnetwork flow evaluations, reflects network flow changes significantly better than its fixed counterpart.

• Record URL:
  http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B9853-52X1TRD-N-1&_cdi=59087&_user=10&_pii=S1877042811010731&_origin=browse&_coverDate=12%2F31%2F2011&_sk=999829999&view=c&wchp=dGLzVzb-zSkzV&md5=3cf24146c3ec5fc34fc751b0b52adc54&ie=/sdarticle.pdf
• 
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/18770428
• Supplemental Notes:
  • Abstract reprinted with permission from Elsevier.
• Authors:
  • Xie, Chi
  • Kockelman, Kara M
  • Waller, Travis
• Conference:
  • 19th International Symposium on Transportation and Traffic Theory
  • Location: Berkeley CA, United States
  • Date: 2011-7-18 to 2011-7-20
• Publication Date: 2011

Language

• English

Media Info

• Media Type: Web
• Features: Appendices; Figures; Maps;
• Pagination: pp 189-212
• Monograph Title: International Symposium on Transportation and Traffic Theory, 19th
• Serial:
  • Procedia - Social and Behavioral Sciences
  • Volume: 17
  • Publisher: Elsevier
  • ISSN: 1877-0428
  • Serial URL: http://www.sciencedirect.com/science/journal/18770428/53
• Publication flags:

  Open Access (libre)

Subject/Index Terms

• TRT Terms: Entropy (Statistical mechanics); Numerical analysis; Origin and destination; Travel demand; Trip generation; Trip matrices; Trip tables
• Uncontrolled Terms: Elastic demand; Least squares; Transportation networks
• Subject Areas: Highways; Planning and Forecasting; Public Transportation; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 01345412
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 21 2011 10:08AM