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Measurement of Recurring Versus Non-Recurring Congestion: Technical Report

Description: 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.

  • Date Published: October, 2003
  • Publication Number: WA-RD 568.1
  • Last Modified: April 24, 2007
  • Authors: John Ishimaru, Jennifer Nee, Mark E. Hallenbeck.
  • Originator: Washington State Transportation Center (TRAC)
  • # of Pages: 36 p., 349 KB (PDF)
  • Subject: Databases, Estimating, Freeway operations, Freeways, Methodology, Nonrecurrent congestion, Traffic congestion, Traffic delay, Traffic incidents.
  • Keywords: Recurring congestion, non-recurring congestion, transient congestion, freeway performance monitoring, ITS data archiving, incident data.
  • Related Publications: Measurement of Recurring Versus Non-Recurring Congestion, (WA-RD 568.2).


This abstract was last modified April 29, 2008