45 miles an hour seems like a reasonable compromise speed. At 65% the common highway speed limit of 70 mph, it's still fast enough to cross most states in a day, to travel between nearby cities in an hour or so, and to do errands in an afternoon. But a car at that speed has only 41% the kinetic energy as at 70 mph, making colisons less lethal, and has similarly less wind resistance, requiring smaller engines and less fuel.
Maybe I just think trains are romantic...
On the other hand, cars have been getting safer and faster and more efficient, roads have been getting wider and safer.. only speed limits haven't been lifted to match. A part of me wants to live the utopia where I can get where I want to be in less than half the time it takes today. That'd make the difference between going to my parents for a coffee after work vs having to reserve a full day (if not a full weekend) for the trip.
Trains are not really a solution around here.
I was glad I wasn't driving, because not only is that a greater posted-vs-actual speed difference than I've seen before, but I've never actually driven that fast in my life. I'd have been torn between driving 80 in the right lane and being constantly passed at 10-15mph, or being white-knuckled behind some other vehicle and setting a personal landspeed record.
Speed limits themselves only have a passing correlation to safe traffic speed. Almost nobody actually follows them intentionally at scale (traffic just moves at the maximum safe speed which just sometimes happens to be at or below the posted limit) which is why most municipalities are abandoning the "slap a sign with a low number on it" approach for "traffic calming" road features. Traffic moves at what it considered to be the highest safe speed for the conditions (a bunch of factors too long to list). You're seeing high differences because there's many roads that have speed limits that are unrealistically low for light traffic conditions (often below the designed speed of the road) and traffic density (as opposed to visibly or a sharp curve) was the road condition that was the bottleneck on speed on most busy roads. 'Rona has widened that bottleneck so of course you're seeing bigger differences between the posted limits and the traffic speed on those roads (which is probably all roads if you only ever drive during daytime hours in urban areas).
Edit: kind of got off on a tangent there but the point I should have made is that speed limits are fixed whereas traffic speed is variable based on conditions. As conditions change both slowly over time and day to day/hour to hour the max safe traffic speed changes. With 'Rona chopping congestion across the board it's no surprise that you see traffic speeds much farther from the speed limit on roads where traffic volume was a big factor in the traffic speed.
In my case, rural Finland, it's been the same for as long as I remember. Maximum limit is 120 km/h on freeways (and there are practically none of them where I usually drive), elsewhere on bigger inter-city roads it's 100 km/h during summer and 80 km/h during winter. Lesser roads, never more than 80 km/h.
And traffic never flows significantly faster than the limit. A few km/h over the limit at most. There are some weirdos who drive much faster and are constantly overtaking others, but relatively few people drive like that. If anything, it seems to me that speeding has become less common over the years as the police have tightened the limit at which they'll fine you.
People are basically behaving like it's German autobahn everywhere. Even the informal rules have adjusted - in a major city, you not only respect the right hand rule, but also give right of way to all vehicles on the more major road. The conflict is resolved by blinking headlights.
Honda used to be the most popular brand here (90's and first few years of 00's).
What do you mean by that? If you're covering long distances in the Western US, it's not at all uncommon to be driving 70+ for hours at a time.
That is solely determined by the energy required. And there is, where the electric car excels. A Tesla uses less than the equivalent of 2l of fuel for 100km or in other units achieves 120mpg. In situations you describe, it fares even better, as 60% of the kinetic energy built up is gained back when braking using the electric motors. So mass is much less a problem with electric cars than with combustion engines, which can't recuperate the kinetic energy.
And there are currently more fossil fuel cars on the road with regenerative braking than there are EVs ;-)