Where exactly should the children be “present” for the sign to be in effect? Right by the sign? On the sidewalk within 300ft. of the sign? In any of the school’s buildings (because we all have X-ray vision, you know)? The “default” speed limit on the streets near schools is usually 35 anyway, so I don’t think it would be such a traffic obstruction to just put the unconditional 25 on the near-school stretches. Well-designed traffic signs should be obvious – the more attention you pay to solve the riddle of “are children present or not?” the less attention you’d devote to actual driving, with obvious overall safety consequences.
Here’s another gem from right across the street:
This one is even more puzzling. If, say, on a Saturday Mr. Principal tells his wife he needs to do some urgent work at school, but in reality he just uses his office to get intimate with Ms. Science Teacher – is that a “session” or not? May I park while you do your business, Mr. Principal?
If only there was a way to tell the drivers exactly when to slow down or when it is OK to park… Oh, wait, there is one!, which makes it even less excusable to keep the old, pre-electricity design.