I would make sense, on local, primarily residential streets, to set the speed to 30… except…
There is a clear contradiction between signing a road or street at a low speed and designing that same road or street or stroad for a much higher speed. Because we have built car-centric car-dependent communities, most people are driving on straight wide multi-lane roads that are clearly designed for much higher speeds than they are posted. So posting them at a slower speed is simply wrong.
And the fact that almost everyone is exceeding low posted limits, in line with the design speed of roadways is an acknowledgement that posting lower limits on high-speed roads is not a solution. Nor is appalling automated enforcement, which should anger any sensible democratic person who doesn’t think they should have a predator-prey relationship with their government.
If you want slower speeds, inevitably you have to design the road or street or community for the speed you want people to drive at.
In the Netherlands there are hardly any speed-limit signs, or stop signs for that matter. Because they have redesigned the actual road/street space to the speed specifications that people should be driving at.
