Flashing yellow arrow a factor in 1/2 of crashes at Plymouth intersection

Flashing yellow arrows have become more common throughout Minnesota over the past few years, but they can also create dangerous intersections when drivers don’t use them appropriately. In the northwest suburb of Plymouth, police received a flurry of recent complaints about some drivers taking risks at flashing yellow arrows, and the city’s analysis of crashes at one yellow light intersection revealed some troubling data.

The Plymouth Police Department examined data from March 10, 2016 through Feb. 22, 2017 for the intersection of Rockford Road and Fernbrook Lane. The intersection was the site of 34 crashes, with 16 of those crashes (47 percent) directly related to a vehicle failing to yield at a flashing yellow arrow.

In addition to drivers taking risks at yellow arrows, Plymouth police have received complaints of drivers honking at those in front of them who choose to wait for a larger, safer gap in oncoming traffic. Plymouth Police Chief Mike Goldstein said some of these crashes could have been avoided if drivers were more cautious and courteous.

What's being done?

The Plymouth Traffic Unit has been working with Hennepin County to reprogram and restrict the timing of the flashing yellow arrows to address safety issues. The police department has also requested that traffic lights be changed to disable the flashing yellow arrows when pedestrians push the walk button to increase pedestrian safety in crosswalks. 

Yellow arrow confusion

The Fox 9 Investigators examined crashes at yellow arrow intersections last May, when there were at least 160 flashing yellow arrows in place around the state. MnDOT promotes the flashing arrows as being a "safer, more efficient left turn signal," but had yet to do an analysis of what impact they're having on safety in Minnesota.

Using the state’s open records law, the Fox 9 Investigators obtained crash data for 73 intersections with the new arrows. Since 2014, there have been nearly 780 crashes, more than 340 injuries and at least one death. Rear-end collisions and t-bones were most common type of crashes. Young drivers 21 and under accounted for more accidents than any other age group. Eight of the ten intersections with the most crashes had an increase in collisions after the yellow arrows went in. However, this data only indicates a crash happened at or near an intersection and not if the arrow was a contributing factor. It would appear there might be a connection.

How flashing yellow turn arrows work

The traffic signals feature the standard red, yellow and green arrows, but also include a flashing yellow arrow, which allows a driver waiting to make a left turn after yielding to oncoming traffic. 

What the signals mean:

Red arrow: Drivers must stop and wait – do not enter an intersection to turn.

Solid yellow arrow: The left turn signal is about to change to red – drivers should prepare to stop or complete a left turn with caution.

Flashing yellow arrow: Drivers are allowed to turn left after yielding to all oncoming traffic and pedestrians. Oncoming traffic has a green light, so drivers must wait for a safe gap to turn.

Green arrow: Left turns have the right of way. Oncoming traffic has a red light.

Flashing yellow arrows are covered in driver's education and there are questions on the permit test, but none of Minnesota's driver exam stations have those signals installed on their test courses.