What it takes to get a left-turn arrow

Published 6:27 am Wednesday, December 3, 2014

Jo Clark of Everett writes: “I have a question about an intersection. On 75th Street, heading west at Evergreen Way, traffic backs up for left turns almost every light cycle during the day. There is no left-turn arrow. If someone from the opposite direction is waiting to turn left, it’s very difficult to see if other cars are coming up to the intersection since the waiting car blocks the view. There are also usually pedestrians crossing Evergreen and so you have to watch for traffic coming from across and then it has to coincide with a time there aren’t pedestrians. Have they considered putting left-turn arrows at that intersection?”

Marla Carter of Everett’s Public Works Department responds: “Consideration of adding left-turn phasing for signals involves reviewing the traffic movement volumes (left turns vs. opposing through traffic), crash history and sight distance issues. In the case of Evergreen and 75th, the east/west left turn and opposing through-traffic volumes are not sufficient to meet the guidelines for considering left-turn phasing.

“We checked the crash history and found in the last three years there were only two accidents involving left-turning cars from 75th Street. A review of the sight distance shows although the westbound left turn lane is offset around 2 feet from the opposite side, there is still adequate room to observe opposing eastbound through traffic. We also monitored the traffic flow and observed only moderate queuing for westbound left-turning traffic. Nearly all such traffic was able to be served in one traffic cycle.

“We will continue to monitor the operations of this signal to ensure it continues to adequately serve the traffic demands.”

Have a question? Email us at streetsmarts@heraldnet.com. Please include your name and city of residence. Look for updates on our Street Smarts blog.