People who can't keep their car at a constant speed on the highway; cruise control is the best way to do this if you don't want to keep checking your speedometer. To elaborate: If everybody picks a slightly different speed and maintains it , any encounter between two vehicles will never last very long. There's more distance between any two vehicles, so it's safer, and large, impassable clumps of vehicles are less lik…
Imagine a pedal with a dead spot in the middle that represents 0 acceleration. Pushing down on the pedal increases the rate of acceleration. When you get to speed, ease back to the dead spot to maintain. Lift past the dead spot to decel.
Think of it as a hybrid cruise control. I'm convinced it would solve many traffic congestion problems associated with people not maintaining speed on, say, slight inclines.