Have you ever seen how stressed out drivers behave?

We've all seen that person in a Honda fit who's so terrified of being on the freeway during rush hour they're driving like an overloaded scrap hauler and generally causing a problem in whatever lane they're in.

That doesn't make the roads safer.

Exactly this. I cannot sum this up better. In NZ the police fine such people occasionally, I think there was a case when one such driver caused massive traffic jam during national holiday.