You could also build the roads in such a way to discourage speeding, e.g. don't make roads with a 20mph speed limit look the exact same as those you can go 50mp

You could also build the roads in such a way to discourage speeding, e.g. don't make roads with a 20mph speed limit look the exact same as those you can go 50mph on. If you are physically able to go more than twice the speed limit at a road, something's wrong with the road. I can't recall the number of times driving in Texas I asked myself what the speeding limit was, as it could literally be any number. The road itself sure didn't give me any hints regarding what it was. Ways to do this is by making them a bit more narrow, or in residential areas make them a bit more swerving for example. No need for enforcement, just gently encouraging drivers to drive the proper speed.