Significantly reducing the maximum speed of passenger vehicles would cause millions of Americans to suddenly have untenable commute times.

There are a handful of cities here with mass transit systems that aren't an absolute joke. Everyone who lives outside those cities relies on a car. What you're describing would be political suicide.

Capping cars' speed to 80mhp would not affect commutes at all. Can say that I drive over 75 mph very rarely.

I can't see why the insurance industry hasn't done more to "get people to give up their big cars" - SUVs, in particular. They clearly have the actuarial data showing how much damage those do.

If they have the data and you don’t, why do you assume you’re in the right? Insurance isn’t interested in damage, they’re interested in liability, which is much more closely tied to personal injury than property damage. And it’d be impossible to claim SUV’s don’t help protect the individual most at risk of costing the insurance company money.

That's an interesting point, it could be they have a perverse incentive if their insured are well-protected and thus make smaller claims - but I'd think doing more damage to other vehicles would tend to cancel that out?

That might require some sort of collusion to accomplish. If only one company increases rates for SUV drivers, said drivers will just switch to a lower priced competitor.