As of October 1, 2016, the SWUTC concluded its 28 years of operation and is no longer an active center of the Texas A&M Transportation Institute. The archived SWUTC website remains available here.

167556-1 Report Abstract

Robust Design and Evaluation of Transportation Networks with Equilibrium Under Demand Uncertainty

Jennifer Duthie and S. Travis Waller, University of Texas at Austin, October 2006, 57 pp. (167556-1)

As long-term forecasts of origin-destination (O-D) travel demands are inherently uncertain, future network performance cannot be predicted with certainty.  Neglecting the uncertainties present can result in inaccurate measures of network performance that may lead to incorrect policy decisions.  This work relaxes the assumptions of determinism and independence of O-D demand in solving user equilibrium assignment.  Insight is presented into the impacts of these assumptions through numerical analyses, where demand takes on various types of normal and lognormal multivariate distributions.  The results indicate that incorrect assumptions of independence can, depending on the actual relationship between demands, lead to significant over- or under-estimation of network performance and incorrect network improvement decisions.

Keywords: Origin-Destination, Travel Demand, Travel Patterns, Transportation Network Performance

ENTIRE REPORT (Adobe Acrobat File – 438 KB)