Minnesota Department of Transportation

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Traffic Engineering

traffic engineering workers

Trunk Highway 55 Connected Corridor

Project description

The advancement of Automated Vehicles (AV) and Connected Vehicles (CV) will change many aspects of transportation, including how we drive and how agencies plan and build roads. AV technology includes features ranging from adaptive cruise control, to lane keeping, to fully autonomous vehicles. CV technology, uses forms of wireless communication, such as Dedicated Short-Range Communication (DSRC), to share information with other vehicles and roadside infrastructure, such as location, speed, roadway surface and weather conditions, and signal timing. The National Highway Traffic Safety Administration (NHTSA) has issued proposed rulemaking that would require DSRC in all new light duty vehicles in order to create a common communication network among vehicles. This sharing of information, combined with automated driving features, will facilitate safer, more efficient travel.
AASHTO recently challenged each state to install DSRC infrastructure on at least one corridor (approximately 20 signals) by January 2020. This technology will broadcast Signal, Phase, and Timing (SPaT), and allow for the advancement of Vehicle to Infrastructure (V2I) technology through the broadcasting of SPaT messages over DSRC.

Snow Plow Signal Priority System

Project description

Signal, Phase, and Timing deviceSignal, Phase, and Timing device
Signal, Phase, and Timing (SPaT)

In response to the Connected Vehicle SPaT Deployment Challenge, MnDOT has been working with public and private stakeholders to explore key areas of interest for CV. The highest priority was identified as snow plow and maintenance operations. The Snow Plow Signal Priority (SPSP) system would provide plows the ability to request extended green or early green phases at traffic signals along snow plow routes via DSRC.

MnDOT plans to deploy SPaT at approximately 22 traffic signals along corridors between I-494 and I-94. Two deployment locations have been elected, TH-55 and I-394, each offering a different scenario for application of the SPSP. Along TH-55, signal priority would be given to plows as they approach mainline signals. Deployment on I-394 would occur at interchange signals and ramp meters along the corridor, allowing plows clearing exit and entrance ramps to operate more efficiently.

Project benefits

  • Increase safety and mobility of roadways
  • Improve plowing times and fuel efficiency by reducing time spent waiting at signals
  • Improve productivity/efficiency of gang plowing operations (where the rightmost plow is responsible for clearing ramps and thus, typically falls far behind mainline plows)
  • Establish MN as an active participant in CV technology
  • Develop the Twin Cities Metro Area as a CV testbed to attract private sector technology testing and deployment
  • Gain valuable procurement, licensing, installation, and operational experience with CV technology
  • Learn where the limits of these technologies are and how to design roadways to leverage the benefits and compensate their shortcomings
  • Identify priority considerations for AV/CV legislation and rulemaking¬†
  • Increase MnDOT’s ability to support legislators on new regulations governing the testing and operation of AV

Project documents