Advice from the Seattle Times:

Q: There is a light at the intersection of Northeast 37th Way and Sahalee Way Northeast in Sammamish that appears to be tied to a sensor. When you’re on Northeast 37th Way turning left onto Sahalee Way Northeast, the light changes green almost immediately. It’s terrific! That is, if you’re in a car. I ride a motorcycle, and the sensor doesn’t detect my presence and the light never turns green until a car arrives behind me, which depending on time of day can be quite a wait. Is there anything that can be done, or is there something I can do to trigger the signal?

Read the answer here.