Determining Length of Red Intervals for Effective Protected-Permissive Left Turn Phase Operation with Flashing Yellow Arrow Signal

Protected-permissive left turn (PPLT) phasing has been popular and widely used in many urban intersections in North America because of its operational benefits. A significant number of intersections have recently been upgraded with four-section signal heads with flashing yellow arrow (FYA) indication for an effective protected-permissive left turn operation. The present study seeks to find appropriate length of two red times whose roles are important, but different during the FYA-PPLT phasing. One is red time for delayed-start of permissive left turn movements; the other is additional red time for delayed-start of opposing through movements. Micro-traffic simulation and conflict analysis are explored to assess the effects of the red time length on intersection efficiency and safety. A useful reference, which describes the balanced length of the two red times under varying traffic levels, is developed as a result.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AHB50 Standing Committee on Traffic Control Devices.
• Corporate Authors:

  Transportation Research Board

  ,    
• Authors:
  • Mahbub, Muqtasid
  • Kang, Min-Wook
  • Lee, Joyoung
• Conference:
  • Transportation Research Board 98th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2019-1-13 to 2019-1-17
• Date: 2019

Language

• English

Media Info

• Media Type: Digital/other
• Features: References; Tables;
• Pagination: 4p

Subject/Index Terms

• TRT Terms: Exclusive permissive phasing; Flashing traffic signals; Left turn phase; Microsimulation; Red interval (Traffic signal cycle); Signalized intersections; Time duration; Traffic safety; Traffic simulation; Yellow interval (Traffic signal cycle)
• Uncontrolled Terms: Conflict analysis; Flashing yellow arrow
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; Safety and Human Factors;

Filing Info

• Accession Number: 01698290
• Record Type: Publication
• Report/Paper Numbers: 19-00205
• Files: TRIS, TRB, ATRI
• Created Date: Mar 1 2019 3:51PM