written by Todd DePastino 

Road accidents were a problem in World War II Britain, despite the effective ban on all private cars after March 1942.

The source of the problem was largely the Yanks—over 2 million of them—and their fleet of trucks and jeeps.

The Americans knew how to drive, even on narrow English lanes, but the steering columns on their military vehicles were all on the left.

Left-sided steering wheels make sense in the United States, where custom and law dictate that drivers stick to the right-side of the road. A driver, then, has a better view of oncoming traffic which flows to the driver’s left in the other direction.

The problem in Britain, of course, is that drivers must travel on the left side of the road. That means British vehicles have steering columns on the right.

American trucks in Britain were a hazard, in part, because drivers couldn’t see oncoming traffic as well. US military vehicles shipped to Britain had “CAUTION LEFT HAND DRIVE” stenciled on the back as warning. Several scenes in Masters of the Air include this detail as the airmen load up in deuce-and-a-halves to travel their hardstands.

But why did Americans, who were once subjects of the Crown, drive on the opposite side of the road as their British cousins?

The answer, it seems, has to do with the long distances and heavy loads that American travel entailed. Driving large teams of oxen and horses was best done on the left for most right-handed people. Draft animals to the right, drivers on the left, near the center of the road.

Keeping on an animal’s left also helped separate horses and oxen on the road. People driving their animals would pass each other in the middle of the road as the traveled in opposite directions, while the animals would keep toward the edges.

Until this American innovation, pedestrians and riders stuck to the left side of the road, the way Ancient Rome had mandated it.

But why was Left-Hand Traffic the default mode until the American 18th century?

No one really knows, though much legend and guesswork gets passed around the internet. Did Pope Boniface VIII decree that pilgrims traveling to Rome in the Jubilee Year of 1300 must keep to the left? Probably not.

Did the Roman Legions walk and ride on the left to keep their sword hands—their right—at the ready in case opposition came from the other direction? Sounds reasonable.

Did the British prefer the left to keep right hands free for greetings? Maybe.

The American Conestoga Wagon, invented around 1750 by Pennsylvania Dutch (German Mennonites), changed the rules of the road in early America. These enormous inland freight haulers were pulled by up to eight horses or a dozen oxen and could carry 12,000 pounds—over twice the tonnage of those WWII deuce-and-a-halves.

With such large teams, the driver had to work dismounted or, perhaps, with a partner riding the left-side horse closest to the wagon. Most drivers walked to the left of the team to work the whip in the right hand and reins in the left.

The Conestoga’s big brake handle was on the left, as was the rude “lazy board” where the driver could ride for short periods.

American Conestoga Wagon from 1840-1850

Conestoga Wagon, ca., 1840-1850 (National Museum of American History)

The enterprising Pennsylvania Protestants did great business selling wheat, corn, and some finished goods back east on the Philadelphia and Lancaster Turnpike and also out West on Forbes Road to Pittsburgh and Ohio Country. In 1792, the Turnpike passed the first Right-Hand Traffic rule based on the Conestoga design. The Massachusetts Turnpike followed up the same in 1821.

Why the National Road, which followed the route of Braddock’s March in 1755, stubbornly clung to a Left-Hand Traffic rule is anyone’s guess.

By 1850, however, the right-hand convention was universal in the United States. And American travelers visiting their British cousins famously struggled with the roundabouts and street-crossings.

With so many Americans driving so many vehicles in Britain between 1942-1945, the traffic confusion must have been enormous.

I’d be interested to know just many people were killed or injured on British roads during the war, and how many of those accidents involved Americans.

After all, the “CAUTION LEFT HAND DRIVE” alerts might have helped the locals, but they did little for the young car-happy men behind the wheels in the Old World.