Development of Guidelines for Implementation of Contraflow Left-Turn Lanes at Signalized Intersections

Recently, an innovative intersection design, contraflow left-turn lane (CLL) design has been increasingly implemented at the signalized intersections in China. It was designed for solving the problem that the capacity of the existing regular left-turn (LT) lanes is insufficient for the increasing left-turn demand at a signalized intersection. The basic idea of this design is to provide additional capacity to left-turning vehicles by making use of the opposing lanes dynamically. With the CLL design, more existing lanes (i.e. opposing through lanes) can be used for moving left-turn vehicles, thereby increasing the efficiency and capacity of the intersections and reducing the left-turn queue lengths at the intersections. In addition, this new design can be easily implemented without modifying the intersection in a way that requires major constructions. To introduce this cost-effective new design to the transportation practitioners in USA, the proposed study will systematically analyze the impacts of CLL on the intersection operational performance and will develop a model for estimating the length of the CLL that will maximize the operational benefits of this new design. In addition, traffic simulation based study will be conducted to valid the modeling results. After that, a step by step design procedure for converting an existing conventional LT intersection to a CLL will be developed. The outcome of the project will provide tools and design guidelines to the traffic engineers for appropriately implementing of this innovative intersection design in USA in the future.

Language

• English

Project

• Status: Completed
• Funding: $80951
• Contract Numbers:

  69A3551747133

• Sponsor Organizations:

  Center for Advanced Multimodal Mobility Solutions and Education

  University of North Carolina, Charlotte
  Charlotte, NC  United States  28223

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590
• Managing Organizations:

  University of North Carolina, Charlotte

  Department of Civil and Environmental Engineering
  9201 University City Boulevard
  Charlotte, NC  United States  28223-0001
• Project Managers:

  Fan, Wei

• Performing Organizations:

  Texas Southern University, Houston

  3100 Cleburne Street
  Houston, TX  United States  77004
• Principal Investigators:

  Qi, Yi

• Start Date: 20181001
• Expected Completion Date: 20200930
• Actual Completion Date: 20200930

Subject/Index Terms

• TRT Terms: Contraflow lanes; Geometric design; Guidelines; Highway capacity; Highway design; Highway operations; Innovation; Left turn lanes; Length; Mathematical models; Signalized intersections; Traffic congestion; Traffic engineering; Traffic safety; Traffic simulation
• Geographic Terms: China
• Subject Areas: Design; Highways; Operations and Traffic Management; Safety and Human Factors;

Filing Info

• Accession Number: 01699626
• Record Type: Research project
• Source Agency: Center for Advanced Multimodal Mobility Solutions and Education
• Contract Numbers: 69A3551747133
• Files: UTC, RIP
• Created Date: Mar 24 2019 5:05PM