Washington Administrative Code
Title 392 - Public Instruction, Superintendent of
Chapter 392-151 - Traffic safety-School safety patrol
Section 392-151-035 - School crossing warning and speed limit signs

Note:

The Washington state department of transportation defines when children are present as:

1. School children are occupying or walking within the marked crosswalk.

2. School children are occupying or waiting at the curb or on the shoulder of the roadway and are about to cross the roadway by way of the marked crosswalk.

3. School children are present or walking along the roadway, either on the adjacent sidewalk or, in the absence of sidewalks, on the shoulder within the posted school speed limit zone which extends three hundred feet in either direction from the marked crosswalk.