Traffic Forecasting Accuracy Assessment Research

Accurate traffic forecasts for highway planning and design are crucial for ensuring that public dollars are spent wisely; however, there is only a small library of empirical studies that have examined traffic forecasting accuracy in the United States. Even with limited availability, these studies are important as they address three critical benefits: insight on observed inaccuracy levels to decision makers and the public, a demonstration of the value of advanced models and data techniques, and assistance in identifying new or advanced methods to improve traffic forecasting practice. Such studies are rare because of numerous challenges, including data availability and staff turnover, and because of a lack of consistency in accepted procedures for preserving detailed information on forecasting methods and data used in the analysis. These challenges are slowly being addressed as the importance of empirical accuracy reporting has grown. The need for the demonstrated value of advanced modeling and data techniques has also grown, as these techniques require significant resources. In traffic forecasting, departments of transportation in Wisconsin, Minnesota, and Ohio have conducted targeted reviews of some traffic forecasts within the past 6 years. Other fields have demonstrated the effectiveness of such reviews, most notably the National Oceanic and Atmospheric Administration (NOAA) through their highly successful Hurricane Forecasting Improvement Program. Building on these earlier, limited reviews, especially in the context of improving technology, there is a need to expand documentation and assessment of traffic forecasting experience to improve future applications. The objective of this study was to develop a process to analyze and improve the accuracy, reliability, and utility of project-level traffic forecasts. To meet this objective, addressing the following components: (1) analysis of traffic forecasting accuracy and usefulness using information from various sources including, but not limited to, state departments of transportation (DOTs), metropolitan planning organizations (MPOs), counties, and other transportation agencies actively involved in forecasting travel demand in competitive modes; (2) assessment of transportation agency experience with respect to accuracy of various forecasting approaches; (3) identification of methods for improving flexibility and adaptability of available forecasting techniques to changing assumptions and input data; (4) consideration of risk and uncertainty in the forecasts; and (5) identification of potential methods to help the traffic forecasting industry improve forecasting usefulness and accuracy while improving their ability to communicate and explain these forecasts to affected communities. In the context of this study, the terms accuracy and reliability are meant to address how well the forecasting procedures estimate what actually occurred; utility is meant to encompass how well a particular projected outcome informs a decision; and project level is meant to include a single project or a bundle of related projects. The product of this research provides guidance to MPOs, state DOTs, and others to improve the accuracy, reliability, and utility of traffic forecasting methods as applied to transportation planning, design, and operation efforts—both short and long term.


  • English


  • Status: Completed
  • Funding: $350000
  • Contract Numbers:

    Project 08-110

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Goldstein, Lawrence

  • Performing Organizations:

    University of Kentucky, Lexington

    Kentucky Transportation Center
    College of Engineering, 176 Raymond Building
    Lexington, KY  United States  40506-0281
  • Principal Investigators:

    Erhardt, Gregory

  • Start Date: 20170214
  • Expected Completion Date: 20190701
  • Actual Completion Date: 20190701
  • Source Data: RiP Project 40805

Subject/Index Terms

Filing Info

  • Accession Number: 01598916
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 08-110
  • Files: TRB, RiP
  • Created Date: May 8 2016 1:00AM