Reader asks why flashing yellow arrows rather than solid green ball
- Blog Post by: Tim Harlow
- December 6, 2012 - 11:51 AM
My column the other day on the new flashing yellow left turn arrows promted several questions from readers, including this one: "Flashing yellow arrow makes sense, but why not use standard, circular green? Same thing: left allowed after yield."
While true, the flashing yellow arrows are more intuitive to drivers than the circular yield-on-green indicators, said Jerry Kotzenmacher, a traffic systems specialist for MnDOT. That's because green means go whereas yellow means caution.
"A green ball might lead you to turn when a car is coming without making that last check before going," Kotzenmacher said. "It's an extra message to make sure the way is clear" before proceeding.
Kotzenmacher said studies have shown the flashing yellow arrows have reduced driver confusion and kept traffic moving.
The arrows will make signals "more efficient" and take away one of the biggest complaint of drivers: sitting at a left turn arrow when nobody from the opposite direction is coming.
Traffic signals can be programmed to show a solid yellow arrow during times of heavy traffic such as in rush hours. They can be set to flash yellow during off-peak hours.
With the flashing arrows installed at an intersection in Ham Lake earlier this week, there are now more than 133 of the arrows operating in Minnesota, and more are on the way.
In fact, the old system with the solid green ball is going the way of the dodo bird. They can no longer be made according to the Manual of Uniform Traffic Control Devices, a publication of the Federal Highway Administration which lists the standards used by road managers nationwide to install and maintain traffic control devices on all public streets, highways, bikeways, and private roads open to public traffic.
© 2015 Star Tribune