I have friends working in traffic departments for various cities. They tell stories of sending out speed recommendations based on the design of the road, house

I have friends working in traffic departments for various cities. They tell stories of sending out speed recommendations based on the design of the road, houses, intersections, etc. The speed limits come back from the politicians much reduced. Roads are designed to be driven at a particular speed. This is the speed most drivers use. Having a lower speed limit gives a false sense of safety. It's basically the "think of the children!" argument.