Measurement of Recurring Versus Non-Recurring Congestion: Technical Report

This report documents the technical results of a WSDOT-sponsored research effort to determine the nature and cause of congestion on Seattle-area freeways based on an analysis of available databases of traffic incidents and freeway performance. The focus of this effort was to develop a methodology for estimating freeway congestion as a function of its estimated cause (principally, its recurring or nonrecurring nature) by using readily available data, as well as to develop, implement, and use a prototype tool set that would apply that methodology.

The resulting methodology and tool set produce estimates of congestion (delay) associated with recurring and non-recurring conditions as a function of various user-specified parameters and assumptions. The method is able to analyze Seattle area corridors using data from existing databases. The process makes extensive use of the TRAC-FLOW analysis process, as well as supplementary prototype tools.
Publication Date: 
Wednesday, October 1, 2003
Publication Number: 
WA-RD 568.1
Last modified: 
10/12/2016 - 15:42
John Ishimaru, Jennifer Nee, Mark E. Hallenbeck.
Washington State Transportation Center (TRAC)
Number of Pages: 
Databases, Estimating, Freeway operations, Freeways, Methodology, Nonrecurrent congestion, Traffic congestion, Traffic delay, Traffic incidents.