Travel Time Reliability: Its Measurement and Prediction

10:00 AM - 11:00 AM
George List, North Carolina State University, Raleigh, and
Richard Margiotta, Cambridge Systematics
Center for Transportation Analysis Seminar
NTRC-2, Room 201
Email: Jan-Mou Li

Reliability is a topic of great interest to researchers and practitioners alike. With the impacts of congestion, incidents, and other unforeseen circumstances, people are concerned about being able to get to work on time, catch flights, get to doctor's appointments, get children to and from day-care centers, and other events where being on-time matters. Shippers are concerned that deliveries need to be on-time, or penalties may be incurred and production processes may be disrupted. This presentation addresses both the issue of reliability measurement and assessment as well as its prediction for future time periods. The measurement and prediction of reliability can help agencies understand the performance of their systems and monitor how reliability improves over time. It equips them to answer questions like:

  • What is the distribution of travel times in the system?
  • How is the distribution of travel times (or rates) affected by recurrent congestion and non-recurring events?
  • How are freeways and arterials performing relative to reliability performance targets set by the agency?
  • Are capacity investments and other operational actions helping improve the reliability of the travel times?
  • Are operational improvement actions and capacity investments helping to improve the travel times and their reliability?

Analytical tools and techniques are discussed as well as the results of their application.

About the Speakers
Dr. George F. List is a professor in Department of Civil, Construction, and Environmental Engineering of North Carolina State University. He has 35 years of experience in both academia and consulting and is a nationally recognized scholar for his work in network operations modeling and control, freight network planning, and asset management. Dr. List is interested in transportation system observability, control, and network planning; sensor design and system instrumentation, wireless technologies, traffic management systems, highway capacity and safety modeling, quality of service assessment, network capacity investment planning; modeling, simulation, and optimization of transport systems and networks; freight logistics; railroad system planning design and operation; multi-objective optimization. More information about Dr. List can be found in

Dr. Richard Margiotta, is a Principal with Cambridge Systematics. He has 32 years of experience in transportation planning and engineering, and has held positions at the University of Tennessee, Transportation Research Board, SAIC, and the Knoxville Metropolitan Planning Organization. Dr. Margiotta's recent work has concentrated on performance measures for congestion and operations, especially in the area of travel time reliability, including NCHRP Project 3-68, Guidebook for Freeway Performance Measures, and SHRP2 Project L03, Analytic Procedures for Determining the Impacts of Reliability Mitigation Strategies, and FHWA’s Mobility Monitoring Program. He is currently assisting FHWA in the implementation of MAP-21 performance measures and developing a mobility monitoring program for the Florida Department of Transportation.

Please contact Jan-Mou Li (, 865-9461461) if you want to discuss collaborative opportunities with the visitors after the seminar.


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