How important is travel time reliability to commuters? How much emphasis do drivers place on reliable travel times when deciding on alternative route or mode choices? Does the incorporation of traffic operations and management strategies impact travel time reliability, and, if so, what is the impact on traveler behavior? Does a change in the travel time reliability of one transportation alternative make it more or less desirable than other alternatives in the eyes of key decision makers?

The Portland Metro region in collaboration with the University of Arizona received federal research funding through the Strategic Highway Research Program (SHRP2) L35 pilot project to study the impacts of traffic and transit travel time reliability on the prioritization of transportation alternatives to begin to answer some of these questions.

The primary task of the SHRP2 L35A project is to build support for investments in operations through pilot testing a reliability performance metric or an economic value of travel time reliability and incorporating it into the analysis of investment alternatives at an agency level. The research involved with this project contains several major contributions to the application of travel demand models and tools to regional planning analysis:

-- Development of a survey method that can be used to capture a local value of travel time reliability

--Demonstrated method for incorporating travel time reliability in route choice for dynamic traffic and transit assignments

--First demonstrated example of applying an integrated dynamic traffic/transit assignments and trip-based travel demand model with feedback to determine mode choice impacts of travel time reliability

This presentation will focus on these major contributions from the SHRP2 L35A project, including an overview of the research methodology, applications to a multi-model study area in the Portland region, and key takeaways from regional planners and decisions makers.