Drivers will see flashing yellow arrow turn signals added at 14 intersections this year in Kent’s north industrial valley as the city continues to upgrade its traffic signal system.
The city installed its first flashing yellow arrow signals in 2016 at nine downtown intersections, including four along Fourth Avenue, because national studies show the signals improve intersection efficiency, increase safety and are more effective at getting drivers to yield to oncoming traffic, according to city transportation documents.
Drivers can turn on a flashing yellow arrow if no vehicles are coming rather than having to wait on red for a green arrow, which can take a whole cycle of green lights for other directions. The yellow arrow also has reduced collision rates involving vehicles turning left during permissive left turn signal phases, according to city documents.
The City Council approved a $802, 869 low bid on Jan. 15 from Woodland-based Northeast Electric to upgrade the traffic signal system. The city received five bids, with a high of $911,509.
A grant of $782,237 from the state Department of Transportation’s Highway Safety Improvement Program will pay for most of the project, with the rest coming from the city’s capital budget. City Public Works staff applied for the state grant. A federal grant covered the $400,000 project in 2016.
“The flashing yellow arrows we are installing require essentially a new brain to be able to add that function to it,” Public Works Director Tim LaPorte said to the council. “This would complete the work that was envisioned a number of years ago to add flashing yellow arrows to the signal system in the Valley.”
LaPorte said city staff at some point would like to add the flashing yellow arrows to certain West Hill and East Hill intersections.
In addition to the yellow arrows, the project includes five new traffic signal cabinets, new controllers at 20 intersections and five traffic cameras. The cameras are used to monitor traffic conditions, said Rob Brown, city transportation engineering manager, in an email. The city has 17 traffic cameras, including two used to monitor the Green River.
Flashing yellow arrows will be added at the following intersections:
• 68th Avenue South and South 228th Street
• 68th Avenue South and South 204th Street
• 68th Avenue South and South 196th Street
• 84th Avenue South and South 208th Street
• 64th Avenue South and South 212th Street
• 84th Avenue South and South 196th Street
• 84th Avenue South and State Route 167 northbound ramp
• 84th Avenue South and SR 167 southbound ramp
• 76th Avenue South and South 228th Street
• 64th Avenue South and South 228th Street
• 58th Place South and South 200th Street
• 72nd Avenue South and South 196th Street
• 80th Avenue South and South 196th Street
• 58th Avenue South and South 228th Street