Chandler has implemented flashing yellow left‐turn signals at intersections throughout the city to enhance traffic flow and improve safety. This type of signal was approved by the Federal Highway Administration (FHWA) after research conducted by the National Cooperative Highway Research Program (NCHRP) demonstrated that the flashing yellow arrow heightens driver awareness when making left turns in front of oncoming traffic.
Understanding the Flashing Yellow Arrow Signal
The flashing yellow arrow traffic signal consists of four arrow lights that are used exclusively for left‐turning traffic.
How Flashing Yellow Arrows Work
For a visual explanation of how flashing yellow arrows improve traffic flow, watch this informative video from the city of Wellington, Florida.
Safety Impact of Flashing Yellow Left Turn Arrows
Chandler collected and studied crash statistics for the three years before and three years after the installation of the flashing yellow arrow signals. The study results indicated that, on average:
- Left‐turn crashes dropped by 22% from 2.6 crashes per year to 2.0 crashes per year.
- Total intersection crashes also decreased by 22%, from 11.1 crashes per year to 8.7 crashes per year.
Benefits of Flashing Yellow Left Turn Arrows
- Reduces Confusion: Eliminates motorist confusion as to the meaning of the circular green light, which can be mistaken for a protected left turn.
- Increases Opportunities to Turn Left: Provides more opportunities for drivers to turn left safely.
- Versatile Application: This can be used in all intersection and signal configurations.
- Adaptive Control: Enables the left‐turn control to be varied during different times of the day.
Resources and Research
For more information on the research supporting the safety benefits of flashing yellow arrows, you can explore the following resources:
- Overview of Flashing Yellow Arrows for Safer Left Turns: This overview from the National Cooperative Highway Research Program (NCHRP) provides a summary of the impacts and benefits of implementing flashing yellow arrows.
- NCHRP Report 493: Evaluation of Traffic Signal Displays for Protected/Permissive Left‐Turn Control: Access the full report that provides detailed research
and findings on the safety and operational improvements associated with flashing yellow arrows.