> I've been in rush hour (where keep-to-the-right-unless-passing is very strictly enforced) in bumper-to-bumper traffic and the left two (out of 6) are completely empty and everyone is doing 'around' the speed limit.
I've been on interstates in every continental US state and I've never seen this, but I think something has been lost in translation because "bumper-to-bumper" and "everybody doing the speed limit" are mutually exclusive as I understand the terms. If everybody on the road can fit into the right lane with enough space in-between to do the speed limit, that is done but I wouldn't call that traffic "bumper-to-bumper". I would call that light traffic. Bumper-to-bumper is when the space between cars really starts to contract, because everybody is going substantially below the limit, or because people aren't maintaining a safe distance.
Once the road has too many cars to fit them all into the right lane at the speed limit, then in every state I've driven, cars start using the left lane for travel, not just passing. If the right lane is so full that it can only sustain 5 below the limit, then people start driving in the left lane and stay there for as long as the right lane won't support speed-limit traffic. In this kind of traffic you'll start to have cars moving fast alongside each other with low relative velocity.
Have you ever driven in Philadelphia during high-traffic, non-rush hour times? 75mph easily, with at most half a car length between every car. I didn't believe a friend's dad when he talked about "bumper-to-bumper 80mph traffic" in the highways around the Philly suburbs but it's absolutely the case.
!!!! 2 meters separation at 70 km/h gives you a tenth of a second to react to anything the car in front of you does, that's flatly insane. Where in the world do people drive like that?
Seriously, that's objectively insane. Try the ruler drop test for reaction times if you don't believe me, a 10th of a second to even initiate your response isn't realistic and obviously gives no time for the response itself to have effect. What I'm saying is that at a tenth of a second, you can't even start to press the brake pedal in time, let alone have enough time to actually slow down.
In America, with only 2 meters between vehicles the traffic would be inching forward at a snails pace, under 20 km/h at least. "Stop and go", as in people would stop their car and then drive forward slowly when a larger gap ahead of them appears.
If the car in front of you instantaneously goes to 0, yes.
Reminds me of driving in western Virginia, people drive insane there. This is going into Amsterdam in the morning. Highly recommend “Not Just Bikes” on YouTube if you want an interesting comparison between roads here vs. Canada/US.
I've been on interstates in every continental US state and I've never seen this, but I think something has been lost in translation because "bumper-to-bumper" and "everybody doing the speed limit" are mutually exclusive as I understand the terms. If everybody on the road can fit into the right lane with enough space in-between to do the speed limit, that is done but I wouldn't call that traffic "bumper-to-bumper". I would call that light traffic. Bumper-to-bumper is when the space between cars really starts to contract, because everybody is going substantially below the limit, or because people aren't maintaining a safe distance.
Once the road has too many cars to fit them all into the right lane at the speed limit, then in every state I've driven, cars start using the left lane for travel, not just passing. If the right lane is so full that it can only sustain 5 below the limit, then people start driving in the left lane and stay there for as long as the right lane won't support speed-limit traffic. In this kind of traffic you'll start to have cars moving fast alongside each other with low relative velocity.