driving: the left lane

Much of the current misunderstanding over the left lane stems from the 55 mph national speed limit that was enacted in 1974, according to the National Motorists Association (NMA), a grassroots drivers’ alliance that lobbies for traffic regulations and safety issues. Before this, passing on the left was an unwritten rule of the road, but after the speed limit was enacted, drivers believed that if they were maintaining the posted speed limit then they could chill anywhere. “Because the speed limit was too low, drivers trying to pass weren’t allowed to and it caused a lot of problems, and it still does,” says Shelia Dunn, Communications Director of the NMA.

Reserving the left lane only for passing other cars—known as “lane courtesy”—reaps surprising benefits, however. Here’s why you should reserve your left-lane use for passing only.