Analytical Travel Forecasting Approaches for Project Level Planning and Design

As transportation professionals seek to address future transportation needs, they are often faced with complex issues that necessitate a rich understanding of those factors likely to impact travel choices--often with limited insights available from observed data. Analytical tools must then be developed and applied at a suitable level of spatial and temporal detail to help inform investment decisions. Areas that lack demand-based models are faced with a different set of challenges, where observed counts are often used as the primary basis for generating facility-specific forecasts in the future. The emergence of post-processing techniques during the 1970s and 1980s adequately supported planning and project development needs for mobility-enhancing projects, where the most pressing analytical questions centered on facility usage levels. But with the saturation levels of congestion on existing roadway systems, the focus especially in urban areas seem to be more on managing travel demand and operational efficiency. The temporal aspect of the extent of congestion is difficult to capture with existing techniques. For heavily congested urban study areas and corridors, it is important to capture the effects of peak spreading at a project level. There also seems to be a need to develop post-processing tools to evaluate residual demand and peak spreading. Study of unconstrained demand and effect of capacity constraints on travel demand is another added layer of information that needs to be analyzed to develop purpose and need justifications for transportation projects as well as land use density changes. More recently, increasingly restrictive funding environments for transportation projects coupled with an emerging interest in the contribution of transportation to climate change have resulted in a heightened consideration of transportation alternatives that better manage travel demand and contribute to operational efficiency. Corresponding improvements in transportation methods are needed that are capable of providing plausible, defensible forecasts to support planning and project development for transportation projects while providing a sound analytical basis for describing transportation impacts that may not be adequately addressed with current post-processing methods. The specific objectives of the project are: (a) conduct a national review of project traffic forecasting guidelines established at the federal, state, and local level and identify the strengths, limitations, and examples of their application, and update current methodology guidelines, such as NCHRP 255, based on findings; (b) expand the project traffic forecasting methodology guidelines to incorporate appropriate new data sources and system level methods such as geographic information system (GIS), Origin-Destination (OD) matrix estimation, dynamic traffic assignment, and network simulation, etc. for the purposes of addressing common project development purposes, needs, and impacts with particular attention to land development and congestion; and (c) develop guidelines to factor peak-spreading, diurnal distribution of travel, and capacity constraints for project level planning.<p> </p>


  • English


  • Status: Proposed
  • Contract Numbers:

    Project 8-83

  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  USA  20590

    American Association of State Highway & Transportation Officials

    444 North Capitol Street, NW, Suite 225
    Washington, DC    20001

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  USA  20001
  • Project Managers:

    Srinivasan, Nanda

  • Start Date: 20100613
  • Source Data: RiP Project 26465

Subject/Index Terms

Filing Info

  • Accession Number: 01463923
  • Record Type: Research project
  • Source Agency: National Cooperative Highway Research Program
  • Contract Numbers: Project 8-83
  • Files: TRB, RiP, USDOT
  • Created Date: Jan 3 2013 2:32PM