Only about 10% of the world’s automobiles drive on the “wrong” side of the road. I had my first experience with the British system in the Cayman Islands this summer, part of the West British Isles. Not only do they drive on the wrong side of the street, but the driver’s seat was on the wrong side of the car. The Caymanian government has wisely put special tourist license plates on all rental vehicles, largely so native drivers know to stay clear of visiting Americans. Fortunately, all the Caymanians I almost ran over were very polite and usually just motioned with their index finger (I had to be clear on which finger) for me to shift to the other lane.
The countries that hold to this backwards system – countries like Grand Cayman, England, Australia, New Zealand, and Japan – have the luxury of being isolated from all their neighbors that drive the “right” way. I guess that’s one more benefit of being an island. The continents are not so lucky. Imagine the chaos if Canada and Mexico used the British system. How would you design a system where drivers had to switch road sides when they hit the US border?
The history of “road direction” is more lore than anything else, but it appears that driving on the wrong side is the older tradition. As far back as the Greeks and Romans, travelers and armies marched on the left side of roads because most men are right-handed. You wanted your sword arm facing travelers coming from the opposite direction. In addition, since most men wore swords on the left, riding your horse on the left side of the road meant that a drawn sword faced the person coming from the right side of the road. So traveling on the left became the norm, mainly for safety, and it eventually made sense to institutionalize that system for efficiency. Historians have found edicts from Roman and Medieval times telling visitors and pilgrims to keep to the left when traveling.
This tradition seemed to change during the renaissance. With the decline of serfdom, farmers and peasants wanting to sell their goods had to get them to market. The wagons pulled by various animals – horses, oxen, mules – frequently lacked a seat for a driver. As a result, the driver would sit on the rear left animal; left so he could hit all the animals with his whip. If he were seated on the right side animal, he’d have to whip across himself to hit the animals on the left.
The problem was that driving on the left, while riding on the rear left animal, placed the driver on the curb side of the road. It became difficult to see what was coming up the center of the road, and it was especially tricky when passing other carts or pedestrians. You could hit them with the wheels on the right side of your cart and not know it! To avoid such collisions, the drivers kept their traditional seats on the left-side animal, but started driving their wagons on the right side of the road, effectively placing the driver in the middle of the street. In this way, the driver could see better and avoid crushing pedestrians or hitting other carts. And so, the traffic patterns slowly evolved in most places to driving on the right side of the road.
So why do some countries still hold to the old way of driving on the left?
Aristotle, Montesquieu, and Tocqueville wrote that geography is just as much an influence on a country as law, religion, or culture. In America, for instance, our gun culture is a function of the frontier geography that shaped our history. The driving preference of that small 10% of nations who drive on the left is a function of their relative isolation. That is, you are only safe driving on the wrong side if you can prevent people who drive on the right side of the road – like most places in the world – from getting at you. Only a place like an island, or a place isolated by jungle or deserts, can get away with driving on the wrong side. Think of it as evolutionary theory on a different level. Like Darwin’s finches, the isolation of automobiles on islands and remote regions of the Earth has protected their unique abilities to drive on the wrong side.
We’ll have to see how long the species can survive.