Balance of Traffic Distribution on Multiple Left-Turn Lanes: A Compositional Analyzing Approach

Underutilization of multiple lanes serving the same traffic movement is commonly seen in highway. It decreases the capacity of subject segment. This study took dual and triple left-turn lanes at signalized intersection as case study, and analyzed unbalanced distribution of left-turn traffic on them. Since unbalanced lane volumes result from drivers’ unequal lane preferences, by subjecting to the sum-constant constraint among left-turn lane volumes, lane volume data can be applied to analyze influences of geometric design and traffic control on drivers’ lane preferences. Left-turn lane volumes collected in field were formatted as compositional data in current study. One-way and two-way compositional analysis of variance model was respectively formulated to estimate main factor effect and joint factor effect on mean of volume composition. A “staying in the simplex” approach was introduced in model estimation. Regression results suggested that the influences of each significant factor on balance of traffic distribution could vary with infrastructure layout and signal phase. The variance of geometric design and traffic control, such as vehicle turning curve, length of upstream segment, location of multiple left-turn sign, signal phase/cycle length, could affect the traffic distribution. The balanced status could be achieved at different levels of each factor. Besides the main factor effect, it’s also found that joint effect of two factors could enhance or weaken the influence of one factor on specific lane volume ratio with respect to total left-turn volume. Based on the regression results, some advices were provided for engineers to improve unbalanced traffic distribution on dual and triple left-turn lanes.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AHB65 Standing Committee on Operational Effects of Geometrics.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Li, Li
  • 0000-0002-7580-3559
  • Zhang, Dong
  • Chang, Yuntao
  • Zheng, Liyong
  • Peng, Zhong-Ren
• Conference:
  • Transportation Research Board 96th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2017-1-8 to 2017-1-12
• Date: 2017

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 22p
• Monograph Title: TRB 96th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Behavior modification; Drivers; Geometric design; Highway capacity; Left turn lanes; Signalized intersections; Traffic control; Traffic distribution
• Uncontrolled Terms: Driver preferences; Dual left turn lanes; Triple left turn lanes
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 01628067
• Record Type: Publication
• Report/Paper Numbers: 17-02485
• Files: TRIS, TRB, ATRI
• Created Date: Mar 2 2017 5:04PM