Lol, I think they should be low and stay low and there should be more enforcement
For me, I live in a quiet neighborhood. The residential street outside my apartment has speed limit signs of 20mph. People are trying to walk their dogs and kids. 9 out of 10 cars go 40-50mph. Part of that is road design. The road is new, straight, barrier and speed bump free. Worse, if you try to obey the law and go 20 the person behind you will get road rage and then illegally pass on the left (going into the opposite lane) or pass on the right and swerve around to get to the left turn lane.
That said, a street a block over is 25mph with speed bump and at least 1 of 3 cars races to each bump. And 1 of 20 just flies over the bumps.
This is a street with apartments and condos one one side and a park and elementary school on the other.
There might be some roads that don't need enforcement (somewhere in Nevada) but even in outside of the city, say LA to Vegas or SF to LA there's enough traffic that speeders cause accidents.
There's also a great video I stumbled across yesterday
So if have a car going 70mph and they slam on their breaks to avoid an accident. When they stop they'll have expended 4900 units of kinetic energy. Another car, same weight, going 100mph slams on the breaks. When their car has expended 4900 units of kinetic energy they still have another 5100 units to get rid before their car will stop because 70^2 = 4900, and 100^2 = 10000. In other words, after they've applied as much stopping force as the 70mph car required to come to stop they're still going over 70mph
The point being, speeding issues scale exponentially, not linearly.
American drivers are extremely poor by international standards though - perhaps because of the relative ease of getting a licence, perhaps because of poor enforcement of road traffic laws.
Look at the level of road fatalities [1] in the US - comparable with developing world countries. I vividly remember travelling on the interstate in the US in the 2000s, and seeing a couple of burnt out recent wrecks (most likely fatal) by the highway side every hour or so. That's incredibly shocking to someone from the EU. For contrast, I've driven by the site of a serious accident perhaps twice in my life here in Ireland - which has a road fatality rate 1/4 that of the US.
I think this has more to do with the prevalance of driving among the population. At least compared with India I remember looking into this, and it did.
Being a driver or passenger on a roadway in India is much more risky, but people in India are far less likely to die in this scenario because they spend so much less time in those situations than Americans.
So you're saying that in your neck of the woods 60+% of drivers aren't texting, the average following distance is >0.5 seconds (ideally always, but at a bare minimum when it's icy out), the average speed through a stop sign is under 20mph, people choose to stop when the sun is blinding them instead of hoping for the best, ...?
Suppose drivers are perfect though. Things happen. You can't account for every kid, dog, ... running out in front of you. You don't know when there will be gravel on the road greatly increasing your braking distance. Top speeds of 15-25 are reasonable in a residential area in the sense that anything more greatly increases the chance and severity of pedestrian injury.
For me, I live in a quiet neighborhood. The residential street outside my apartment has speed limit signs of 20mph. People are trying to walk their dogs and kids. 9 out of 10 cars go 40-50mph. Part of that is road design. The road is new, straight, barrier and speed bump free. Worse, if you try to obey the law and go 20 the person behind you will get road rage and then illegally pass on the left (going into the opposite lane) or pass on the right and swerve around to get to the left turn lane.
That said, a street a block over is 25mph with speed bump and at least 1 of 3 cars races to each bump. And 1 of 20 just flies over the bumps.
This is a street with apartments and condos one one side and a park and elementary school on the other.
There might be some roads that don't need enforcement (somewhere in Nevada) but even in outside of the city, say LA to Vegas or SF to LA there's enough traffic that speeders cause accidents.
There's also a great video I stumbled across yesterday
https://www.youtube.com/watch?v=i3D7XYQExt0
Summary: Kinetic energy = 1/2 * mv^2
So if have a car going 70mph and they slam on their breaks to avoid an accident. When they stop they'll have expended 4900 units of kinetic energy. Another car, same weight, going 100mph slams on the breaks. When their car has expended 4900 units of kinetic energy they still have another 5100 units to get rid before their car will stop because 70^2 = 4900, and 100^2 = 10000. In other words, after they've applied as much stopping force as the 70mph car required to come to stop they're still going over 70mph
The point being, speeding issues scale exponentially, not linearly.