The flashing yellow arrow (FYA) is an important tool for improving the efficiency of signalized intersections. The key benefits of FYA are the ability to vary the type of left-turn phasing to suit traffic volume demands throughout the day and to vary the phase to provide optimal corridor two-way progression across multiple timing plans.

Why FYA?

Less Delay: At FYA-equipped intersections, the operator has the ability to change the phasing mode to provide less restrictive phasing during off-peak times, giving drivers more opportunities to make left turns and reducing delays.
Improved Two-Way Progression: With protected/permissive left-turn phasing, phase order can be varied by timing plan to provide optimal turning progression across a range of cycle lengths.
Cost-Effective: A typical FYA retrofit costs between $10,000 and $30,000 or roughly 5% to 15% of the cost of a new signal.

SRF Can Help

FYA Planning

Should an intersection be retrofitted? How much will a retrofit cost?

  • FYA retrofit feasibility evaluation
  • FYA retrofit cost estimates
  • FYA retrofit benefit/cost prioritization

FYA Design

What revision work must be done to retrofit an existing signal with FYA?

  • FYA retrofit traffic signal design
  • Signal construction administration and inspection

FYA Operations

Should I vary the type of left turn phasing by time of day? How can I optimize my corridor timing plans to make best use of FYA?

  • Traffic count data collection
  • Left turn phasing by time-of-day analysis
  • Development of coordinated signal timing plans for FYA corridors
  • Signal controller data entry to enable and optimize FYA operations
  • Coordinated timing plan field implementation and fine-tuning

FYA Problems & Solutions

Problem Solution
Signal is built with protected only phasing on one or more approaches but is only needed for an hour or two a day. Retrofit protected only approach(es) with FYA. Collect seven-day traffic counts. Develop TOD schedule for phasing to use on each approach.
Corridor is built with five-section protected/permissive signal indications on mainline. Leading left turn phases result in sub-optimal two-way progression on mainline. Retrofit signal indications with FYA. Collect times and seven-day tube counts. Develop updated coordinated timing plans.
Corridor is built with protected only, protected/permissive, or split phase signals and requires long minimum cycle lengths. Coordinated timing plans would be beneficial outside of peak hours but are not practical given cycle length requirements. Retrofit signal indications with FYA. Collect times and 7-day tube counts. Develop updated coordination timing plans.
Signal has FYA indications but runs protected/permissive all day. Operations are unsafe during peak periods and inefficient during off peak. Collect seven-day traffic counts. Develop TOD schedule for phasing to use on each approach.
Corridor has FYA indications but is not optimized. Collect times and seven-day tube counts. Develop updated coordinated timing plans.