Evaluating Detours for a Major Construction Project in the Era of Real-Time Route Guidance (Project D3)

Major road construction projects can be significant sources of traffic congestion and motorist delays. Maintaining agencies typically attempt to mitigate these impacts by designating detour routes and providing project information to motorists. This information can be conveyed through a variety of media, from traditional static and variable roadway signage placed in the field to electronic media including web sites, radio and television advertisements, call centers, text messaging, and navigation apps. In this era of real-time traffic information and in-vehicle route guidance, it is not clear to what extent this detour information is used and which messaging components are most effective. This study used the Interstate 59/20 reconstruction project in Birmingham, AL to evaluate the detour planning process and the effectiveness of the resulting detour and information strategies. The objective was to develop recommendations and best practices that can be applied to future construction projects and allow transportation agencies to allocate project resources to greatest effect. The evaluation included a review of the transportation modeling process used to project traffic diversions and designate detour routes, a survey of motorists to determine the sources of information they used to choose detour routes during construction, and a study of traffic patterns before, during, and after the project to understand if and how detour patterns changed over the course of the one-year project. The study resulted in recommendations for conducting planning studies for large roadway projects and found that factors such as transit usage assumptions, employer work policies, and roadway capacity assumptions can have significant impacts on model accuracy. The survey found that motorists used a wide variety of information sources when selecting detour routes and that they often modified those routes based on real-time data. The travel time and traffic count analysis found that detour patterns did vary over time as the transportation system reached equilibrium. It also found that actual traffic patterns during the reconstruction project did not always match responses to the motorist survey, suggesting that motorists used designated detour routes initially but adjusted them during the course of the project.


  • English


  • Status: Completed
  • Funding: $55000
  • Contract Numbers:


  • Sponsor Organizations:

    Office of the Assistant Secretary for Research and Technology

    University Transportation Centers Program
    Department of Transportation
    Washington, DC  United States  20590
  • Managing Organizations:

    Southeastern Transportation Research, Innovation, Development and Education Center (STRIDE)

    University of Florida
    365 Weil Hall
    Gainesville, FL  United States  32611
  • Project Managers:

    Tucker-Thomas, Dawn

  • Performing Organizations:

    University of Alabama, Birmingham

    Department of Civil, Construction and Environmental Engineering
    1075 13th Street South
    Birmingham, AL  United States  35294
  • Principal Investigators:

    Sullivan, Andrew

  • Start Date: 20191115
  • Expected Completion Date: 20220630
  • Actual Completion Date: 20230105
  • USDOT Program: University Transportation Centers Program

Subject/Index Terms

Filing Info

  • Accession Number: 01729869
  • Record Type: Research project
  • Source Agency: Southeastern Transportation Research, Innovation, Development and Education Center (STRIDE)
  • Contract Numbers: 69A3551747104
  • Files: UTC, RIP
  • Created Date: Jan 30 2020 9:05PM