> the latter contributes to the “prison state”.

That's not why (though that's a good point). The reason is because we believe in solving the problem at it's root, not just punishing ppl who normally are just reacting to the design of the street.

You can't have a wide, straight street and then not expect speeders.

> But suspended drivers who cause a fatal accident should do time in prison. People who leave the scene of an accident should do time.

I've never met anyone who has said that those ppl shouldn't do time. At that point, we're out of the street design convo. It is obviously criminal.

> Licensed individuals who stay at the scene, i think that should be handled civilly.

And there lies the problem. Most crashes are NOT criminally intended. They are just a random person who was a bit too sleepy or wasn't paying attention. That's where street design comes in: it force that person, who's not paying attention, to slow down. Additionally, reduce demand for that person to even be driving by providing alternatives (bus lanes, bike lanes, etc).