Roads commonly carry traffic at a different speeds than listed speed based on actual conditions, perception of conditions, condition and nature of vehicles and because speeds are often set inefficienctly.
Its not uncommon to see stretches with traffic constantly packed 4+ lanes going 75+ each way.
Trying to put the same burden of vehicles through at 65 with 300 ft between would be a joke. A given lane would carry less than half actual traffic. Bad traffic would become a city wide disaster.
Then consider that you can only impose this on a portion of drivers per year and drivers have to drive with those without governors indefinitely.
You also discount issues with safety by following at an appropriate distance. Trying to fall back 300 ft can only be achieved by driving too slow leading to both passing and people taking this new huge space whist giving you the finger leaving you with even less space.
If we're concerned with traffic throughput then shouldn't we just increase the allowed speed? Why even have a limit in the first place?
I don't understand your point about having to slow down to follow at a safe distance. If I pull onto a highway and find myself _right_ behind someone I can decrease my speed by one or two mph to fall back to a safe following distance. How is that not safe? The car behind me, who should already be either already at a safe distance or adjusting their own distance should have no issues here.
What I think you mean to say is that because you're assuming that everyone else on the road is behaving in an unsafe manner you believe that you, too, have to behave in an unsafe manner. This simply is not the case.
I'm not sure where you are driving (or if you drive anywhere) but you can't actually drop speed substantially with cars right behind you and if you tried to open a space people would just move into that space. Then you don't have that space AND you have cars maneuvering around you. You will have drastically increased your chance of having an accident without acquiring a buffer.
Areas that are already burdened as far as the amount of traffic they can bear, which is basically every major urban area in America, see traffic moving at a high rate of speed with 20-30 feet between cars.
Picture a simple chute in which you are dumping jelly beans one at a time. Even at the same speed of descent you will be able to drop 1/3 of the beans if you wait 3 seconds between drops instead of 1. Everyone trying to keep 300 feet between to be "safe" would create an expanding parking lot behind that would crash the entire traffic systems ability to function at all.
When everyone started arriving 3 hours late for work businesses would fine themselves dysfunctional including critical businesses. People would die because emergency vehicles couldn't move. The mayor would be on TV discussing what they would do about the collective insanity.
Anyway this is an awfully long way to say people do need the ability to control the speed of their car in order for the current flawed highway system to function normally. People do actually have cause to pass. They sometimes do have a reason to drive slower than the limit. Others need to exceed it briefly or in an emergency.
Its not uncommon to see stretches with traffic constantly packed 4+ lanes going 75+ each way.
Trying to put the same burden of vehicles through at 65 with 300 ft between would be a joke. A given lane would carry less than half actual traffic. Bad traffic would become a city wide disaster.
Then consider that you can only impose this on a portion of drivers per year and drivers have to drive with those without governors indefinitely.
You also discount issues with safety by following at an appropriate distance. Trying to fall back 300 ft can only be achieved by driving too slow leading to both passing and people taking this new huge space whist giving you the finger leaving you with even less space.