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.
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
Should an intersection be retrofitted? How much will a retrofit cost?
- FYA retrofit feasibility evaluation
- FYA retrofit cost estimates
- FYA retrofit benefit/cost prioritization
What revision work must be done to retrofit an existing signal with FYA?
- FYA retrofit traffic signal design
- Signal construction administration and inspection
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
|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.|