RES2017-01: Improving Effectiveness of HOV Facilities – Behavioral & Operational Considerations

The HOV corridors on Interstates 24 and 65 in Middle Tennessee have a violation rate of approximately 85 percent during peak hours of operation. The lack of enforcement zones on the left hand side of the interstate makes enforcement of the HOV restrictions impossible for law enforcement officers to implement safely. Further, the lack of left hand exits makes access and egress difficult, especially in times of heavy congestion. The objective of this study is to use revealed preference data obtained in the form of single and high occupancy vehicle counts in mixed flow and HOV lanes to formulate discrete choice models of mode and lane choice as a function of travel times in either lane grouping. Vehicular delay functions are developed on the basis of observed operational data to estimate travel times as a function of demand for travel on a particular segment of the interstate. Stochastic user equilibration is performed by solving the choice models and vehicular delay functions simultaneously to determine flows and travel times in the corridor. Hydrocarbon, carbon monoxide, and oxides of nitrogen emissions are estimated using regression-based air quality models based on the EMFAC 2002 data implemented in the FREQ10 air quality model implemented by the State of California Air Resources Board Emissions Inventory Section (ARB-EIS). These air quality models are incorporated into the user equilibrium models for the purpose of evaluating environmental impacts of various strategies for operations management. Given current peak demands and future design hourly volumes, operational strategies of maintaining current operations, reversion of the HOV lane to a mixed flow lane, and heavy enforcement resulting in a ten percent violation rate have been evaluated and assessed. Results of the modeling process reveal that it similar operational outcomes would occur from continuing the current operational policies and reversion of the HOV lane to a mixed flow lane with neither strategy clearly preferred for all operational and environmental quality metrics. However, strict enforcement of the HOV lane would likely result in poorer outcomes for the corridor with regard to both operations and air quality. This is likely the result of the following: (1) demand for travel in single occupancy vehicles is quite inelastic with respect to travel time for the corridors under consideration; (2) most users place little value on the potential time savings afforded by the HOV lane because the lanes are so difficult to enter and exit during peak time; and (3) higher violation rates tend to allow for easier access to and egress from the HOV lanes. The results of the modeling effort will be validated by using macroscopic modeling tools based on implementation of the Cell Transmission Model and microsimulation using VISSIM.


  • English


  • Status: Completed
  • Funding: $199,383.09
  • Contract Numbers:


  • Sponsor Organizations:

    Tennessee Department of Transportation

    James K. Polk Building
    Fifth and Deaderick Street
    Nashville, TN  United States  37243-0349

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Managing Organizations:

    Tennessee Department of Transportation

    James K. Polk Building
    Fifth and Deaderick Street
    Nashville, TN  United States  37243-0349
  • Project Managers:

    Oldham, Jason

    Chen, Yu-Jen

  • Performing Organizations:

    Lipscomb University

    One University Park Drive
    Nashville, TN  United States  37204
  • Principal Investigators:

    McDonald, Mark

  • Start Date: 20171101
  • Expected Completion Date: 20190430
  • Actual Completion Date: 20191010
  • USDOT Program: Transportation, Planning, Research, and Development

Subject/Index Terms

Filing Info

  • Accession Number: 01682705
  • Record Type: Research project
  • Source Agency: Tennessee Department of Transportation
  • Contract Numbers: RES2017-01
  • Files: RIP, STATEDOT
  • Created Date: Oct 4 2018 3:12PM