I guess neither humans or bots are trained well on that. It's pretty stupid anyway. The kids should cross the street at normal crossings like everyone else, not just anywhere a huge yellow beast stops and flips out a sign.
In rural areas, like where I live, there aren't any marked crossings, and there really isn't any reasonable place to put them. If you mark a crossing it would only ever be used by the one or two houses near it, and only by school children, because there's really no need for anyone to walk across the street otherwise. The school buses stop directly in front of each child's house. There aren't any locations where a bus could pick up multiple children without making them have to walk an unreasonable distance, so each kid's house is a stop.
Also, the speed limit on my road is 45 mph, and cars routinely drive 55 mph... so having the "huge yellow beast" with flashing red lights and a flipped-out, flashing red stop sign is definitely necessary.