Paper Details

TRB 91st Annual Meeting (January 22-26, 2012)

Event Number:	493
Event Title:	Research in Traffic Flow Theory and Characteristics, Part 4 (Part 1, Session 403; Part 2, Session 433; Part 4, Session 493)
Event Date:	Jan 24 2012 8:30AM- 10:15AM
Event Location:	Marriott, Salon 2
Event Description:
Event Agenda:

Traffic Speed Variance Modeling with Application in Travel Time Variability Estimation (12-2618)

Traffic speed variance is defined as a measure of the dispersion of space mean speeds among drivers. Empirical speed-density observations exhibit a structured traffic speed variance which has been found to be associated to the road accident rate, the fatality rate, and travel time variability. The objective of this paper is to propose a generalized traffic speed variance function to describe this structured variance and identify its potential applications. In nature, the proposed speed variance function is a response of the speed-density curve with two additional parameters. A series of logistic speed-density curve with varying parameters is used in the proposed traffic speed variance function with different performances. This traffic speed variance model will help to unveil the underlying mechanism of some empirical traffic features such as spontaneous congestion or capacity drop.

Authors
     Wang, Haizhong , Oregon State University
     Li, Zhixia , University of Wisconsin, Madison
     Hurwitz, David S., Oregon State University
     Ni, Daiheng , University of Massachusetts, Amherst