Have you seen the video on the 85th percentile speed by traffic engineer and Strong Towns founder Charles Marohn?
In it he claims that much of the non-compliance isn’t down to wilful disregard for the law, it’s more down to how our brains work and you have to engineer roads correctly if you really want to bring down speeds.

https://youtu.be/NDYQaa3K_BA

This is based on people driving in a way that almost no one does in reality.