Stupid Question ™
May 20, 1999
By John Ruch
Q: Why do Americans drive on the right side of the street, while the British drive on the left?
A: Here’s the current pat answer: The British left-hand practice dates to medieval times, when staying to the left would keep the average right-handed traveler’s sword arm between himself and passing strangers.
The right-hand practice was invented during the French Revolution for no clearly stated reason and was spread across Europe by Napoleon.
The enemy British stayed lefty to spite France, and the U.S. went righty to spite Britain.
Like most theories on this subject, it’s very tidy—and wholly unsupported by evidence.
The key fact is that driving on the right and driving on the left work equally well. It doesn’t matter which one a society chooses; the important thing for traffic safety is simply that it does choose one.
History suggests that lefty/righty is not so much a clear, linear progression of ancient tradition as an arbitrary choice repeatedly reinvented to suit local circumstances. The current practices centering around the automobile are just the most recent—and widespread—choice.
Some sources note that all large carriages were steered from the right edge of the seat (supposedly so the whip in the right hand wouldn’t hit passengers), and presume this means that the vehicles drove on the left just like modern British right-hand-steered cars.
The one exception was the American Conestoga wagon, which was inexplicably steered from the left of the wagon and driven on the right side of the road.
This may reflect pre-existing custom. But right-steered carriages didn’t result in universal left-hand driving. The Germans and Norwegians drove on the right; Austria and Italy actually switched back and forth depending on the region.
Early cars were modeled on the carriage and were almost all steered from the right. For many years they were driven without trouble in countries with both the right- and left-hand practice.
The first major car with the steering wheel on the left was the 1908 Ford Model T, which revolutionized car sales. Left-hand steering wheels were nearly universal by the end of World War I. And driving on the right side of the road was standard across most of Europe by the late ’20s.
Britain may have stayed lefty because it was slower to adopt cars and didn’t have major highway links to Europe that would force standardization.
Once chosen, the systems went way beyond mere custom—they were set in stone by the car’s unprecedented amount of traffic law and specially created roadways.
Britain actually considered switching to the right in the 1960s, but decided it would be too expensive.
The British system spread to its former colonies, while the American system gained further favor among industrial superpowers. All of Europe (except a couple islands) now drives on the right.