Flashing yellow left turn arrows are showing up at signalized intersections on county highways. The flashing yellow arrows are part of an effort to increase traffic flow and maintain safety. 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.
The new display provides traffic engineers with more options to handle variable traffic volumes. It can also use the most optimal type of control depending on traffic conditions, keeping traffic flow safe during heavy traffic while reducing delay when traffic is light. This safety ability allows it to be used in places where the more restrictive three-arrow signal would have otherwise been required.
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 red, yellow and green indications, which keeps drivers moving.
A national study demonstrated that drivers found flashing yellow left-turn arrows more understandable than traditional yield-on-green indications (individual traffic signal lights).
The meanings of left turn arrows
Solid 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.
Solid yellow arrow
The left-turn signal is about to change to red and drivers should prepare to stop or prepare to complete a left turn if they are legally within the intersection and there is no conflicting traffic present.
Flashing 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.
Solid green arrow
Drivers have the right of way. Oncoming traffic has a red light.
Flashing yellow arrows not used all the time
An advantage of the flashing yellow arrow display is that it gives traffic engineers the flexibility to use specific indications during different times of day. This means that the flashing yellow arrow or steady green arrow may not be seen every time you approach the intersection. This can reduce your wait times at a signal using this display compared to traditional left turn signals.
Deciding on placement
Transportation staff is evaluating flashing yellow left turn arrow control with new traffic signal designs except in places that do not need separate left turn lanes or in places where yielding left turns cannot be safely accommodated.
For existing traffic signals, the County will be assessing and prioritizing locations. Installation is based on a number of factors, including traffic volume, configuration and number of roadway lanes, available sight distance, signal equipment, and signal age. Converting existing traffic signals to use flashing yellow arrow control costs start at $50,000 per intersection. Therefore, older signal systems may not be converted until a major signal revision or reconstruction project is planned.