Signal timing at 160th

Aurora Avenue at N 160th / College Way
Photo by Steven H. Robinson

When the story was published about N 160th being renamed as College Way, a reader had a question about the timing of the turn signal on Aurora at 160th.

The comment:

Shoreline, please check the signal operation of the left turn from 160th to northbound SR 99. It phases from green arrow, very briefly to yellow arrow, red for a couple seconds, then back to flashing yellow. Similar intersections simply change from green to flashing yellow. A lot of drivers simply drive through the short red phase.

Here's the response from the City traffic engineer whose responsibility is to time signals on Aurora:

The City of Shoreline operates the signals on Aurora from 152nd St to 205th St. As for how the flashing yellow left arrow works, it is supposed to sequence as follows:

• 1. Solid red
• 2. Solid green
• 3. Solid yellow
• 4. Solid red
• 5. Flashing yellow
• 6. Solid yellow
• 7. Solid red

In fact, a solid yellow arrow being displayed after a solid green arrow is a requirement on how flashing yellow arrows operate in the Manual on Uniform Traffic Control Devices, the national standard for traffic devices and operations.

The traffic engineer is in the process of re-timing the signals along Aurora and said he will review the pedestrian activity and the eastbound left turning vehicles.