information from SDOT

To improve pedestrian safety, contractors working for the City of Seattle will be installing photo enforcement cameras at five locations during May and June. They will be located near the following schools:  Roxhill Elementary and Holy Family School in West Seattle, Dearborn Park Elementary in Southeast Seattle, Bailey Gatzert Elementary in Central Seattle, and Eckstein Middle School in Northeast Seattle.
 
The cameras will issue citations to drivers that exceed the school zone speed limit of 20 mph. The school zone speed limit is in effect for typically one hour in the morning as students arrive at school, and one hour in the afternoon when the school day ends. Flashing beacons have been installed to emphasize the times when the school zone speed limit is in effect.  The cameras will issue warnings for 30 days beginning September 2 and will start issuing citations in early October.