I asked a sheriff and even he didn't know. The rule is simple. If you see a child at 10 a.m. on a Saturday near a school zone, the speed limit drops to 25 mph. The reason for this should be obvious.
Most schools have playgrounds, attracting kids at all hours of the day.
Others may be near a Little League field, such as near Rosemary Elementary School on Hamilton Avenue in Campbell, attracting kids all times of day. The McCarthy Boulevard off-ramp from southbound Interstate 880 will be closed through Friday from 9 a.m. to 4 p.m. Use the next exit to reach Ranch Drive. David Barr of San Jose is frustrated. At least once a week when he takes the ramp from Almaden Expressway to Highway 85, he waits and waits. Eventually, the next person back honks and they take off, feeling guilty for running the red.