Guidance for Left-Turn Flashing Yellow Arrow (FYA) Implementation in Nebraska

In recent years, various municipalities in Nebraska have transitioned to the use of the flashing yellow arrow (FYA) for permissive left-turns in accordance with MUTCD guidelines. A preliminary study conducted by the University of Nebraska Lincoln and City of Lincoln (S 27th & J-St, S 33rd & Pioneer, S 84th & Firethorn, Wedgewood & O-St) during 2019-2020 provided some evidence that the new protocols are working well. The FYA provides safety benefits while providing more flexibility and versatility in field operation (e.g., phasing sequences, modes, and displays). However, the best practice of FYA arrangement (e.g., phasing, signing) remain unclear. Inappropriate combinations of the FYA display mode may lessen the effectiveness of the FYA application. This study will examine before-after safety of a sample of signalized intersections where changes from solid green ball to FYA installations were made for left turns. Cross-sectional field study on FYA operations will be conducted to evaluate the effectiveness of the left-turn FYA indication at signalized intersections. Specially focus on the investigation if signal display arrangement (e.g., lead/lag phasing, supplemental signing, varying time-of-day operations) had a significant effect. Guidelines on optimal implementation of the FYA considering different traffic conditions (e.g., turning movement, intersection geometry, driver comprehension, etc.) will be developed for transportation agencies.

Language

• English

Project

• Status: Active
• Funding: $177,066.00
• Sponsor Organizations:

  Nebraska Department of Transportation

  1500 Nebraska 2
  Lincoln, NE  United States  68502
• Project Managers:

  Halsey, Lieska

• Principal Investigators:

  Khattak, Aemal

  Zhao, Li

• Start Date: 20230701
• Expected Completion Date: 20250531
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Crash analysis; Flashing traffic signals; Left turns; Signalized intersections
• Identifier Terms: Nebraska Department of Transportation
• Subject Areas: Design; Operations and Traffic Management; Planning and Forecasting; Safety and Human Factors;

Filing Info

• Accession Number: 01881521
• Record Type: Research project
• Source Agency: Nebraska Department of Transportation
• Files: RIP, STATEDOT
• Created Date: Apr 27 2023 5:45PM