Directional Rumble Strips for Reducing Wrong-Way-Driving Freeway Entries

Wrong-way driving on freeways has been identified as a serious traffic safety problem. Drivers who make wrong-way entries onto freeways pose a serious risk to the safety of other motorists and themselves. This study investigated the feasibility of a novel design of directional rumble strips (DRS) to discourage wrong-way entries onto freeway exit-ramps. And the proper implementation locations for different DRS patterns were identified. In phase I of the project, the field tests completed in fall 2015 evaluated the effectiveness of five types of DRS concept designs. The field tests concluded both sound and vibration analysis of five patterns with different configurations. Three patterns (Pattern C, Pattern D Configuration 3, and Pattern E) were recommended for future verification and final implementation. Over the last 6 months, according to the Phase I results and recommendations, the verification field tests were conducted by the Auburn University (AU) team to evaluate the effectiveness of those three recommended DRS patterns. In November 2016, the further field tests were conducted to collect sound and vibration data generated by three DRS patterns at the National Center for Asphalt Technology (NCAT) at AU. Statistical analysis was conducted to examine the difference between right-way and wrong-way direction for both sound and vibration. The results were consistent with the prior results. Pattern C generated significant different sound and vibration in right-way and wrong-way direction at the speed from 10 to 25 mph. While Pattern E showed significant statistical vibration difference at the speed of 45 mph. For sound and vibration data, waveforms in time domain were used to identify the relative loudness of sounds in air and the severity of the vibration as perceived by the driver. In addition, Fast Fourier Transform (FFT) was used to evaluate the vibration amplitude as a function of frequency. This analysis was performed in the frequency domain to gain a deeper understanding of the vibration data. The results implied that the difference in sound and vibration between right-way and wrong-way directions was not significant when driving at the same speed in both directions. However, because average speed of right-way and wrong-way driving will be different at the specific locations of off-ramps where DRS is installed, DRS Pattern C, Pattern D Configuration 3, and Pattern E can achieve the goal to generate larger sound and vibrations for wrong-way drivers than the right-way drivers. An implementation guide is needed to be developed for transportation agencies to identify proper locations for installing these patterns to achieve the best performance based on length and type of off-ramps. Three off-ramps were selected for the experimental implementation. Each location has a specific ramp design feature that works well with each of the design patterns. For instance, at Exit 50 on I-85, Pattern C can be installed on the long straight off-ramp for reducing right-way driving speed when providing an alert to wrong-way drivers. At Exit 58 of I-85, the entrance of the on-ramp is located right next to the entrance of off-ramp terminal. Additionally, the illumination at this location is inadequate at night. Thus, Pattern D Configuration 3, with high visibility reflective painting, can be installed to increase the nighttime visibility and alert wrong-way drivers. The off-ramp at Exit 60 of I-85 has a sharp curve (180 degrees) and a short deceleration lane (around 130 feet). Pattern E can alert wrong-way drivers to slow down and visually informed them about the sharp curve. Wrong-way drivers would receive greater sound and vibration warnings. For the next steps, a research proposal has been developed and submitted to ALDOT for the implementation of DRS patterns at the selected three off-ramps. Field studies and before-and-after comparisons will be conducted to evaluate the operational effectiveness of DRS and help finalize the guidelines for implementation of DRS.


  • English


  • Status: Active
  • Contract Numbers:



  • Sponsor Organizations:

    Research and Innovative Technology Administration

    University Transportation Centers Program
    1200 New Jersey Avenue
    Washington, DC  United States  20590

    Roadway Safety Institute

    University of Minnesota
    Minneapolis, MN  United States  55455
  • Project Managers:

    Stearns, Amy

  • Performing Organizations:

    University of Minnesota, Minneapolis

    Center for Transportation Studies
    Minneapolis, MN  United States 
  • Principal Investigators:

    Luo, Albert

  • Start Date: 20140801
  • Expected Completion Date: 20171231
  • Actual Completion Date: 0
  • Source Data: RiP Project 37481

Subject/Index Terms

Filing Info

  • Accession Number: 01567226
  • Record Type: Research project
  • Source Agency: Roadway Safety Institute
  • Contract Numbers: DTRT13-G-UTC35, CTS-2015039
  • Files: UTC, RiP
  • Created Date: Jun 26 2015 1:00AM