Impact of Cooperative Adaptive Cruise Control (CACC) on Multilane Freeway Merge Capacity

Cooperative Adaptive Cruise Control (CACC) allows vehicles to exchange real-time operational information wirelessly, enabling vehicles to travel in strings with shorter than normal time gaps between adjacent vehicles and ultimately increases the freeway capacity. This study is intended to investigate the impact of CACC vehicle string operation on the capacity of multilane freeway merge bottlenecks, commonly found at on-ramp merging areas on urban freeways. Simulation experiments were conducted using CACC car-following models derived from field test data, together with models of lane-changing of CACC vehicles and manually driven vehicles, as well as a maximum CACC string length constraint. Simulation results reveal that the freeway capacity increases quadratically as the CACC market penetration increases, with a maximum value of 3060 veh/hr/lane at 100% market penetration. The disturbance from the on-ramp traffic causes the merge bottleneck and can reduce the freeway capacity by up to 13%. Nonetheless, the bottleneck capacity still increases in a quadratic pattern as CACC market penetration becomes larger.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AHB15 Standing Committee on Intelligent Transportation Systems.
• Authors:
  • Liu, Hao
  • 0000-0001-5585-6576
  • Kan, Xingan (David)
  • Shladover, Steven E
  • Lu, Xiao-Yun
  • Ferlis, Robert A
• Conference:
  • Transportation Research Board 97th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2018-1-7 to 2018-1-11
• Date: 2018

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 20p

Subject/Index Terms

• TRT Terms: Autonomous intelligent cruise control; Bottlenecks; Car following; Freeways; Highway capacity; Market penetration; Merging traffic; On ramps; Simulation
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; Vehicles and Equipment;

Filing Info

• Accession Number: 01660502
• Record Type: Publication
• Report/Paper Numbers: 18-03570
• Files: TRIS, TRB, ATRI
• Created Date: Feb 20 2018 9:29AM