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Traffic Signal Information

Flashing yellow arrow-a better left turn signal

Flashing yellow left turn arrows are showing up at signalized intersections across the country. The flashing yellow arrows are part of an effort to increase traffic flow and maintain safety. The flashing yellow arrows will move more vehicles through an intersection with less delay by allowing drivers to turn left when there is a gap in the oncoming traffic without having to wait for a green arrow. Drivers making left hand turns during a flashing yellow arrow must yield to oncoming traffic and pedestrians and turn with caution. The flashing yellow left turn arrow is also expected to improve intersection safety by reducing the number of collisions.

More Flexible

The new flashing yellow display provides traffic engineers with more options to handle variable traffic volumes. The flashing yellow display promotes safe traffic flow during heavy traffic volumes while reducing traffic delay when traffic volumes are light.

Less Delay (Wait Time)

Drivers will have more opportunities to make a left turn with the flashing yellow left-turn arrow than with the traditional three-arrow signal display, which keeps drivers moving.

Safer

A national study demonstrated that drivers found flashing yellow left-turn arrows more understandable than the traditional solid green ball displays.

The Meanings of Left Turn Arrows:  

Left Turn Arrow RedSolid red arrow: 
Drivers intending to turn left must stop and wait. Do not enter an intersection to turn when a solid red arrow is being displayed. 

Left Turn Arrow YellowSolid yellow arrow: 
The left-turn signal is about to change to red and drivers should prepare to stop or complete a left turn if they are legally within the intersection and there is no conflicting traffic present.             

Left Turn Arrow Yellow FlashingFlashing yellow arrow:
Drivers are allowed to turn left after yielding to all oncoming traffic and to any pedestrians in the crosswalk. Oncoming traffic has a green light. Drivers must wait for a safe gap in oncoming traffic before turning.  

Left Turn Arrow GreenSolid green arrow: 
Left turns have the right of way. Oncoming traffic has a red light.  

Will the flashing yellow arrow be used all day, on every traffic cycle?

An advantage of the flashing yellow arrow display is that it gives traffic engineers the flexibility to use specific displays during different times of day. This means that the flashing yellow arrow or steady green arrow may not be utilized during every traffic cycle.

How will the City decide where and when to install flashing yellow arrow signals?

The City will evaluate flashing yellow left turn arrow displays with all new traffic signal designs. The City will also be assessing existing traffic signals to prioritize the addition of flashing yellow left turn displays. These future improvements will be based on a number of factors including, traffic volumes, configuration and number of roadway lanes, available sight distance, signal equipment, signal age, and funding availability.

Why not use a solid green light instead of the flashing yellow arrow?

The solid green light is often misunderstood as a left turn indicator. This is because drivers naturally think "green means go." Traffic making a left turn on a solid green light some times does not yield to oncoming traffic, which can result in more crashes. The flashing yellow arrow allows left turns but at the same time communicates the "caution" message to drivers. The flashing yellow arrow is especially effective at intersections with higher volumes of traffic.

Are other cities in Washington using this type of signal?

Yes. Federal Way, Bellevue, and Seattle are some of the Washington state cities that have installed signals with flashing yellow arrows.

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For more information, contact the City of Auburn Transportation Section at 253-931-3010.