Understanding Risks and Opportunities for Ramp Metering Control in a Mixed-autonomy Future

Vehicle automation may change traffic flow dynamics. This will also impact the control of traffic flow via infrastructure-based systems such as ramp metering control. In this work the research team investigated the impact that different levels of automation and connectivity will have on ramp metering control, and proposed modifications to existing ramp metering algorithms to improve their performance under different automation scenarios. The team finds that low-level automation such as adaptive cruise control may decrease mainline throughput by up to 58% on average and increase travel time by 61%. However, full connectivity and automation may decrease travel time by up to 40%. Based on these potential impacts, modifications to the ramp metering algorithm settings were developed for each of the seven automation scenarios. These modifications are shown to improve operations in each scenario.

Language

• English

Project

• Status: Completed
• Funding: $148,495.00
• Contract Numbers:

  69A3552348305

• Sponsor Organizations:

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590

  Minnesota Department of Transportation

  395 John Ireland Boulevard
  St Paul, MN  United States  55155
• Managing Organizations:

  University of Michigan Transportation Research Institute

  2901 Baxter Road
  Ann Arbor, Michigan  United States  48109
• Project Managers:

  Bezzina, Debra

  Stearns, Amy

  Bruner, Britain

• Performing Organizations:

  University of Minnesota, Minneapolis

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

  Stern, Raphael

• Start Date: 20240101
• Expected Completion Date: 20250630
• Actual Completion Date: 20250630
• USDOT Program: University Transportation Centers

Subject/Index Terms

• TRT Terms: Algorithms; Autonomous vehicles; Congestion management systems; Connected vehicles; Ramp metering; Traffic flow; Travel time; Vehicle mix
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; Vehicles and Equipment;

Filing Info

• Accession Number: 01975806
• Record Type: Research project
• Source Agency: Center for Connected and Automated Transportation
• Contract Numbers: 69A3552348305
• Files: UTC, RIP
• Created Date: Jan 8 2026 3:26PM