The National Academies

SHRP 2 L04 [Completed]

Incorporating Reliability Performance Measures in Operations and Planning Modeling Tools

  Project Data
Funds: $1,311,780
Research Agency: Delcan Corporation
Principal Investigator: Yannis C. Stogios, Hani Mahmassani, and Peter Vovsha
Effective Date: 2/6/2009
Completion Date: 10/31/2013

Project snapshot. More details below.

(Project Number)
Impact on Practice
Product Status

A number of reports and guides for incorporating travel time reliability into micro- and meso-simulation models and for integrating demand and network models. The products include first generation software that potentially can be integrated with many simulation packages so they can explicitly address travel time reliability.
The L04 research has resulted in first generation software that offers a new way of applying simulation models to more fully account for the factors that cause non-recurring congestion. The new methods are useful for project evaluation and many types of planning. A Scenario Generator produces randomized input into simulation models in regards to incidents, work zones, weather, etc. A Trajectory Processor generates distributions of travel time from which a broad range of reliability performance measures can be derived.
The prepub report is available here: http://www.trb.org/Main/Blurbs/170716.aspx
The prepub guide is available here:
Staff Responsibility: William Hyman
The emphasis in Project L04 was on improving traffic operations and planning models to reflect travel time reliability and generate travel time reliability as a model output. Phases I and II focused on incorporating travel time reliability in such models. Phase III considered ways to account for the feedback between travel demand and traffic conditions on the network, such as traffic impedances including the variability of travel time.
The objectives of this project were to develop the capability of producing measures of reliability performance as output in traffic simulation models and planning models, and determine how travel demand forecasting models can use reliability measures to produce revised estimates of travel patterns.
The L04 project has addressed the need for a comprehensive framework and conceptually coherent set of methodologies to (1) better characterize reliability, and the manner in which the various sources of variability operate individually and in interaction with each other in determining overall reliability performance of a network; (2) assess its impacts on users and the system; and (3) determine the effectiveness and value of proposed counter measures. In doing so, this project has closed an important gap in the underlying conceptual foundations of travel modeling and traffic simulation, and provided practical means of generating realistic reliability measures using network simulation models in a variety of application contexts.
Status: The project is complete.
Product Availability:  A final report is forthcoming, as well as application guidelines, technical reports of interest to modeling experts, software (a Scenario Generator and a Trajectory Processor) and corresponding user guides.   A fact sheet and project brief are available.
This page was last modified on January 6, 2014.

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