Connected Vehicle Infrastructure University Transportation Center

Safety and Human Factors of Adaptive Stop/Yield Signs Using Connected Vehicle Infrastructure

Final Report

Abstract

Adaptable stop/yield signs have been proposed by some traffic professionals to improve travel time, reduce air pollution, increase fuel economy, and adjust to different traffic conditions such as peak hours, weather, or emergency vehicles. With the advent of Connected Vehicle (CV) technology, we now have the ability to have these signs change based on vehicle-to-infrastructure and vehicle-to-vehicle communications. The placement of a sign type has been traditionally based upon traffic conditions. However, more and more stop signs are being placed instead of yield signs due to liability risk, resident concerns, and potential worst-case crash scenarios.
While adaptable signs have great potential, they must be properly designed and tested to ensure that:

  • The net safety benefits are positive,
  • Drivers interpret and respond correctly to the signs,
  • Drivers pay appropriate attention to the signs without adaptation in the form of relying on past history (e.g., the sign may be different than the prior 10 times the intersection was crossed),
  • There are no other unintended consequences when signs are deployed, and
  • Driver acceptance of the technology is high.

Highlights

  • The performance of participants using the adaptive stop display indicates no difference in stopping behavior in terms of driver input when compared to a traditional stop sign. However, the increased level of compliance to the stop display is something that should be noted; participants were not missing valuable information and were more willing to stop when using the adaptive stop display.
  • A stop made in compliance with the adaptive stop display had a compliance level of 62.11% compared to a stop made at a traditional stop sign (12.44% compliance).
  • When participants were presented with the “proceed with caution” display, they exhibited more risk-averse behaviors that were appropriate when responding to situational changes that required higher levels of attention, such as an increase in traffic.
  • Mean glance duration and frequency decreased rapidly with increased driver experience with the in-vehicle system.
  • The mean eyes-off-road time and number of glances to the in-vehicle device when functioning normally are comparable to that of checking the speedometer (Dingus et al.[1]).
  • Participants were generally able to learn how to use the display quickly.
  • Additionally, the number of glances to the display decreased to about one glance per intersection approach after the first six to eight exposures to the system.
  • Scanning behaviors increased during situations of higher traffic levels, which was a sign that they were not relying totally on the system and still sought information from their surroundings before committing to proceeding through the intersection.
  • For one intersection with an ADT of 1,950 vehicles per day controlled by adaptive stop display compared to traditional stop signs the savings to society in terms of CO2 emissions is $24,349.14 over 45 years.[1] Dingus, Thomas A., Klauer, Sheila G. (2008). The Relative Risks of Secondary Task Induced Driver Distraction SAE Technical Paper Series. Detroit, Michigan.

Publications

Noble, A. M., Dingus, T. A., & Doerzaph, Z. R. (2016). Influence of In-Vehicle Adaptive Stop Display on Driving Behavior and Safety. IEEE Transactions on Intelligent Transportation Systems, PP(99), 1-10. doi: 10.1109/TITS.2016.2523438. http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7426822.

Noble, A. M. (2014, December). Safety, Operational, and Energy Impacts of In-vehicle Adaptive Stop Displays Using Connected Vehicle Technology. (M.S. Thesis in Civil Engineering), Virginia Tech, Blacksburg, VA.

Presentations

Sykes, K., Noble, A. M., Doerzaph, Z. “Using Driver Eye Glance Behavior to Determine Safety Implications of Adaptive In-vehicle Stop Displays.” Summer VT Undergraduate Research Conference, July 2014, Blacksburg, VA.

Noble, Alexandria M. (2014, May). Safety and Human Factors of Adaptable Stop Displays Using Connected Vehicle Infrastructure. Podium and poster presentation for the VCTIR pooled fund sponsors at VTTI.

Noble, A. M. (2014, April). Safety and Human Factors of Adaptable Stop Displays Using Connected Vehicle Infrastructure. Poster session at the Lifesavers National Conference on Highway Safety Priorities, Nashville, TN.

Noble, A. M. (2014, March 29). Safety and Human Factors of Adaptable Stop Displays Using Connected Vehicle Infrastructure. Podium presentation at the Society of Women Engineers Region E Meeting, Blacksburg, VA.

Noble, A. M. (2015, April 24). Safety and Human Factors of Adaptable Stop Displays Using Connected Vehicle Infrastructure. Poster session at the Civil Engineering Research Day, Blacksburg, VA.

Awards

Alex Noble – Featured Graduate Student – The Graduate School at Virginia Tech (February 2014)
Alex Noble – CVI-UTC Student of the Year 2013 (recognized at the 2014 Annual Council of University Transportation Centers (CUTC) Annual Meeting Awards Banquet)
Alex Noble – Dwight David Eisenhower Transportation Fellowship (2015-2016)
Alex Noble – Virginia Tech Diversity Scholar (2016-2017)

Sponsor Organization

Research and Innovative Technology Administration
University Transportation Centers Program
Department of Transportation
1200 New Jersey Avenue, SE
Washington, DC 20590
USA

UTC Grant Manager

Harwood, Leslie
Phone: 540-231-9530
Email: lharwood@vtti.vt.edu

Performing Organization

Virginia Polytechnic Institute and State University, Blacksburg
Virginia Tech Transportation Institute
3500 Transportation Research Plaza
Blacksburg, Virginia 24061
USA

Research Investigators

Noble, Alexandria
Dingus, Tom

Subjects

Highways
Design
Operations and Traffic Management
Safety and Human Factors
Vehicles and Equipment

More Information

RiP URL
Project Poster
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