I don’t understand why adding things that usually make people crash is more beneficial than letting traffic normalize at a speed that may be above the legal lim

I don’t understand why adding things that usually make people crash is more beneficial than letting traffic normalize at a speed that may be above the legal limit. Around me people speed, but you know what’s more dangerous? People who go 55 on the left lane. And trucks that don’t move to the right lane. They are not breaking the law in regards of speed, but everyone that’s going at the normalized pace has to avoid an obstacle. I say leave the speed limit at 75, put everyone through a more difficult test, enforce lane hierarchy and enforce tickets above 90-95. This equals on a traffic speed of 80-85 that’s safer than adding trees and making narrow lanes Edit: after posting this comment I come to realize what living in the US has done to me. I immediately assumed that a road with a speed trap is a highway. Which is all I see every time I get on the car anyway. The American dream.