1. Irvine Traffic Research & Control Center (ITRAC)
User’s Guide for Flashing Yellow Arrow / Protected-Permissive Left Turn Phasing by
Irvine Traffic Research & Control Center (ITRAC)
Jaimee Bourgeois, P.E.
City Traffic Engineer
April 19, 2017

2. Definitions FYA = Flashing Yellow Arrow
PPLT = Protected-Permissive Left Turn
MUTCD = Manual on Uniform Traffic Control Devices
NCHRP = National Cooperative Highway Research Program
FHWA = Federal Highway Administration

3. Overview When to use FYA How to use FYA for PPLT phasing
Why use FYA for PPLT phasing
City of Irvine case study

4. When to Use FYA Permissive left turns PPLT
FHWA issued “Interim Approval for Optional Use of Flashing Yellow Arrow for Permissive Left Turns” in March 2006.
The 2009 edition of the MUTCD includes the Flashing Yellow Arrow as an allowable alternative display for permissive left-turn movements.

5. When to Use FYA (PPLT)
Alternative to the green ball used in traditional PPLT to tell drivers that they can turn left after yielding
Traditional PPLT
FYA PPLT
3-Section FYA PPLT
Interim Approval for Optional Use of Three-Section Flashing Yellow Arrow Signal Faces issued by FHWA in August 2014
Blanket approval provided to the state of California on 4/10/17

6. When to Use FYA Crash history Sight distance # left turn lanes
# opposing lanes
Left turn volume
Opposing traffic speed
Opposing through volume
Left turn delay
Source: Signal Timing Manual (Second Edition), NCHRP Report 812, TRB in cooperation with FHWA.

7. When to Use FYA Negative offsets to be removed
Source: Signalized Intersections Informational Guide, Second Edition, FHWA, July 2013.

8. How to Use FYA Typical Positioning Traditional PPLT FYA PPLT
MUTCD: Figure 4D-12
MUTCD: Figure 4D-11
Signal is placed in the middle of the left-turn lane for FYA PPLT
Must yield to vehicles in intersection and pedestrians

9. How to Use FYA CA MUTCD Key Points
Steady left-turn yellow arrow signal indication shall be displayed following the left-turn green arrow signal indication (Section 4D.20-03C).
It shall be permitted to display a FYA while the adjacent through movement display steady red and the opposing left-turn display green arrow (Section 4D.20-03F).
Lagging left operation: A left-turn green arrow signal indication shall be displayed immediately upon the termination of the FYA (Section 4D.20-03G).

10. How to Use FYA Typical Sequence Steady Red Arrow – Stop
Steady Yellow Arrow – Prepare to stop
Flashing Yellow Arrow – Turn left after yielding to on-coming traffic and pedestrians
Steady Green Arrow – Left-turn drivers have the right-of-way

11. Opposing Through Movement &
How to Use FYA
Sequence With Delay Green & Delay Start of Clearance
Steady Red Arrow
Steady Yellow Arrow
Flashing Yellow Arrow
Steady Green Arrow
Delay Green
Opposing Through
Delay Green
Opposing Through Movement &
FDW Terminates
5S+
2 Secs
Walk indication is displayed while red indications continue to be displayed to oncoming through and/or left turning traffic
DONT
WALK

12. How to Use FYA
Option to program as protected or permissive only modes during certain times of the day
Option to use queue detection to activate the protected only mode (followed by FYA)
Option to use lead/lag left turn operation

13. Why Use FYA Increases capacity of the left turn movement
Safety enhancements (NCHRP Report 493)
The FYA display was shown to offer the highest level of safety
The FYA was found to be the best overall alternative to circular green as permissive signal display for a left-turn movement
FYA was found to have a high level of understanding and correct response by motorists

14. Keep in Mind
Motorist may assume that the FYA left turn is terminating when the FYA indication is illuminated at the same time as the adjacent through movement yellow
No standard MUTCD sign for FYA
Possible design modifications to remove negative offset, size mast arm appropriately, and meet pole wind load standards

15. City of Irvine Case Study
Towngate
Sand Canyon Ave

16. User’s Guide for Flashing Yellow Arrow / Protected-Permissive Left Turn Phasing
Q & A