Hit any area highway when traffic is really moving and try sticking to the posted speed. More often that not, you'll be passed.
"If you have to concentrate on the speed limit," says F/Lt. Thad Peterson, traffic services commander for the Michigan State Police, "That's attentiveness that you are taking away from driving safety."
"We've got this big difference between what people know to be right...and the speed limit." Peterson says it's that variety on the roads--some fast drivers, and some slow--that's more likely to cause a crash.
He says speeds were set artificially low in the 1970s to save gas, and they simply never got fixed. "That led to this assumption...'Drive 55, Stay Alive', 'Speed Kills,'...all those things," he says. "It just held on."