If the design speed of a road does not match the speed limit of the road, people will drive the design speed, cops will learn to sit there all hours of the day waiting for people to mess up, and get ticketed. Instead of just putting up the speed limit sign, city planners should design for the road to be safe without need for the speed limits to be in place. This can mean things like reducing the width of a lane, could mean speed bumps, to purposeful non-straight sections.
> that we can
Highways are designed to be unsafe by design, so without a redesign they require speed limits.
This, of course, applies just as much to the actual topic of the Economist article; new inheritance taxes are just and good, but they should be written to be enforceable, and then they should actually be enforced.
I live on major street where the speed limit is 25 to slow people down. It used to be 35, and people normally go 35-45. The problem is that people go much faster when there is no traffic because the street feels wider. I would love if they redesigned for a slower speed. But there are cars in the middle of the night that drive over 60. It doesn't matter if street is calmed, they will go super fast and only tickets with slow them down.
Those people don't care about speed limits, in part because they are generally set significantly too low. This has the effect of normalizing the scofflaws' attitude even when carried to a genuinely reckless extreme.
Conversely, if you raise the speed limit to the 85th percentile, anyone exceeding it significantly will stand out enough to catch easily.
Speeding is a victimless crime anyway. If you hit something or someone, you were doing something wrong besides speeding.