Most US states cap speed limits around schools at 15mph when children are present. There may also be blinking lights above these signs during times that will be likely.

I'm not sure how much of that Waymo's cars take into account, as the law technically takes into account line of sight things that a person could see but Waymo's sensors might not, such as children present on a sidewalk.

> Most US states cap speed limits around schools at 15mph when children are present.

Are you sure? The ones I've seen have usually been 20 or 25mph.

Looking on Image Search (https://www.google.com/search?q=school+zone+speed+limit+sign) and limiting just to the ones that are photos of real signs by the side of the road, the first 10 are: 25, 30, 25, 20, 35, 15, 20, 55, 20, 20. So only one of these was 15.

I don't think this is accurate, 20mph is more common