From staff reports:

Federal Way’s public works department will install flashing yellow turn signals at the Dash Point Road and SW 312th Street intersection. The turn signals will apply to left turns onto SW 312th Street. The upgrade will cost $12,000 and the intersection accommodates about 21,000 cars a day, according to the city.

When the turn arrow flashes yellow, drivers are permitted to make turns, yielding first to oncoming traffic and pedestrians.

The signals exist at 11 intersections throughout the city, with the first signal installed in 2006. According to the city, collisions at those intersections have decreased by 23 percent, while the severity rates of collisions at the subject intersections have decreased 34 percent.