Citation

Reddy KH, Chakroborty P. Transp. Plann. Tech. 1999; 22(4): 247-270.

Copyright

(Copyright © 1999, Informa - Taylor and Francis Group)

DOI

10.1080/03081069908717631

PMID

unavailable

Abstract

The difficulty of obtaining the origin?destination trip demand (O?D) matrix from population survey data motivated the researchers to estimate the O?D matrix from a variety of data sources, among which O?D matrix estimation from marginal trip totals and traffic volume counts on the links received a lot of attention. One of the key issues in the O?D estimation methods, based on these two data sources, is the specification of trip dispersion. So far, primarily, information on past O?D matrices, trip length frequencies, and approximate idea of the value of O?D elements have been used to specify trip dispersion. In this paper a methodology is proposed which utilizes ordinal information, like the number of trips between a pair of zones is more than between another pair of zones, amongst some of the O?D elements to specify trip dispersion. In addition to this, the proposed method utilizes only marginal trip totals to determine estimates on O?D matrix elements. It is felt that such ordinal information can be obtained relatively easily and with very little resources. The structure of the methodology is such that it can also incorporate information on past O?D matrices and other such cardinal information on O?D elements. The methodology is tested on five different test matrices and on three large O?D matrices. The results show that the proposed methodology works very well and with little computation requirement.