School Zone at 7:40 a.m. With No Children Visible
It is 7:40 a.m. on a Tuesday in September. You approach a school on a two-lane street. A fluorescent yellow-green pentagon-shaped sign shows two figures walking. Below it, a yellow rectangular sign reads "SCHOOL ZONE 20 MPH 7:00–8:30 AM AND 2:30–4:00 PM." There is also a crossing guard standing on the corner but facing away, talking to a parent. No children are currently in the crosswalk, and the light ahead is green. You are running late and traveling 30 mph.
1. Is the 20 mph limit in force right now, and does the absence of children in the crosswalk change that?
Read the worked answer
Yes - it is 7:40 a.m., inside the posted 7:00–8:30 window, so the 20 mph school-zone limit is in force regardless of whether children are visible at this instant. The time window defines when the limit applies; visibility of children does not.
The pentagon shape and fluorescent yellow-green color mark this as a school/pedestrian warning, and the yellow plaque with times makes the 20 a conditional regulatory limit. You are at 30, so you are 10 over inside an active zone. Slow to 20 now. The reasoning the exam tests: school-zone limits are time-based because children arrive in unpredictable bursts - the whole point is to be slow before they appear, not after.
2. The crossing guard is facing away and the light is green. What should you do as you enter the zone, and why does the green light not settle the question?
Read the worked answer
Slow to 20 and cover the brake, scanning the crosswalk, the sidewalk gaps between parked cars, and the guard. A green light gives you the right to proceed through the intersection, but it does not override the school-zone speed limit or a crossing guard's signal.
A guard facing away may turn and step into the roadway at any moment; their raised hand or whistle controls traffic over the light. So the green light answers "may I go through the intersection eventually," while the zone and the guard answer "at what speed and when." Proceed at 20, prepared to stop, and do not accelerate to beat the light - the guard's potential signal is the higher-priority instruction.