I’m afraid I have a hard disagree with conditions.

The road may be safe for higher speeds.

You don’t get to determine that at everyone else’s expense. I regularly drive roads where people average 15-20 over and they are not suitable for those speeds, it’s one fuckup away from a NASCAR-style pileup. People are shit judges of what is safe based on their perceived driving skill (99.999999% of which are horrible) and how important they feel leaving 5 minutes later than they should have for their appointment is.

Anyone significantly outside the average speed is the danger. Faster cars maneuver more abruptly and brake harder, by far creating more danger than those going even modestly over the limit. Too slow cars force those maneuvers and frustrate people making them drive like assholes because cars are an extension of ego for too many people.

Like I said, I’d be fine with Autobahn style limits, but there’s always someone who says fuck the rules because this road can go faster, and that’s why we can’t have nice things.

Edit: And this popped into my head after I wrote this - Even if the road might be capable of safely supporting 70-90mph traffic, cars are not designed to absorb that much energy when something goes wrong. No, "just redesign them" is not an acceptable answer. Changing to a structure that can better absorb higher speed impacts and keep the occupants alive increases weight and thereby reduces economy, and regulations aren't going to let that happen at all.