"If every car sets its cruise control at the same speed" I wish cruise control use was more common on the highway than it appears to me, at least in eastern Massachusetts. I don't want to play passing games; I just want to leave my cruise control set at the speed limit.
Instead, many people seem content to do a bad job modulating their speed with the pedal on hills, and average just under the speed limit instead; or swerve like a maniac across as many lanes as it takes to get ahead a few car lengths. It's really frustrating.
> many people seem content to do a bad job modulating their speed with the pedal on hills,
That's the behavior of my wife's cruise control on her truck; we have to set it to account for 8-10mph slop on either side of the set point, depending on the slope of the hill. It's not even an old truck...
Adaptive cruise makes highway driving so much less stressful. You don't even notice the small changes in speed. It's becoming pretty popular and will soon be standard on even lower end cars.
My wife's car has ACC. I typically set it for about 6-7 over the limit on the freeway (about 85% speed here). Every now and then I will suddenly realize that I'm now going 50. Usually about the time some car flies past my in the left lane and I'm wishing for some traffic enforcement. Then I see that he was really only going the speed I planned to go and I've settled in behind a slow poke.
If every car set its cruise control to the same speed, nobody would ever be able to change lanes; merging and exiting would become an impossibility.
That's why it's so bloody dangerous that clueless folks plod along in the left lane obstructing traffic. It's extremely common to see 1/4mi or more of open roadway ahead of knotted up traffic driving the same speed.
Instead, many people seem content to do a bad job modulating their speed with the pedal on hills, and average just under the speed limit instead; or swerve like a maniac across as many lanes as it takes to get ahead a few car lengths. It's really frustrating.