h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I have been doing a fair bit of research on this! I have included a summarised view here and will add to it in time...


The most commonly accepted explanation of driving on the left is that when travellers on horseback met they preferred to keep to the left so that their sword-hand was free in case of a confrontation as most people are right handed.

However the practice of driving on the left can be traced back even further. Archaeological work on a track into the old Roman quarry at Blunsdon Ridge has shown that this was the Roman practice. The deeper wheel ruts on one side of the track indicate which side of the road the heavily loaded carts that were coming out of the quarry were on, i.e. the left.

The practice of driving on the left was formalised in a Papal Edict by Pope Benefice around 1300AD who told all his pilgrims to keep to the left.

Nothing much changed until 1773 when an increase in horse traffic forced the UK Government to introduce the General Highways Act of 1773 which contained a keep left recommendation. This recommendation became a law as part of the Highways Bill in 1835.

The French, being Catholics, followed Pope Boneface's edict but in the build up to the French Revolution in 1790 the French Aristocracy drove their carriages at great speed on the left hand side of the road, forcing the peasantry over to the right side for their own safety.

Come the Revolution, instincts of self preservation resulted in the remains of the Aristocracy joining the peasants on the right hand side of the road. The first official record of this was a keep right rule introduced in Paris in 1794.

Napoleon (left handed by the way) imposed the rule of driving on the right wherever his armies went. As his armies went everywhere from Spain to Russia this is why Europe drives on the right.

Colonisation by European countries largely determined which side of the road the rest of the world drove on.

France also had quite an empire after the revolutionary wars and the keep right rule spread through much of modern day Europe and to colonies such as Egypt.

The connection with the USA is thought to be General Lafayette who recommended a keep right rule as part of the help that he gave the Americans in the build up to the War of Independence. The first reference to keep right in USA law is in a rule covering the Lancaster to Philadelphia turnpike in 1792.

Britain's imperial expansion spread the keep left rule far and wide. This included India, Australasia and much of Africa (Although many African countries changed to the right later when they became independent).

In Japan in the 1850's gunboat diplomacy forced the Japanese to open their ports to the British and Sir Rutherford Alcock, who was Queen Victoria's man in the Japanese court persuaded them to adopt the keep left rule.

Very early motorcars followed the principle of a horse driven carriage and the chauffeur was seated in the middle. The side steering wheel which subsequently arrived followed the tradition in the country so that the first cars (Benz in Germany) were left hand drive as they drive on the right.
The major exception to this was that racing cars were almost always right hand drive because it was better suited to circuit racing. In the USA Pierce-Arrow were an example of this and in Europe, most pre 1950 Italian Sports cars are Right Hand Drive, including all pre 1956 Lancia's. Remember also that every Bugatti is Right Hand Drive.

Two rather strange theories concern Henry Ford. In the early days of motoring, the buyer would nominate on which side of the car he wanted the wheel to be. But Henry Ford's move to mass production meant there had to be standardisation. He arbitrarily chose the left side. Fords quickly became the most popular vehicles in the US, so Henry's choice was the norm.

American motorists tended to drive on the right to distance themselves, if not their offside fenders, from poles and posts on that side of the road. Once traffic built up, this practice was enshrined in US legislation. There's also conjecture that Henry deliberately broke from the normal practice of putting the wheel on the right to skirt a patent filed by one George Seldon, an attorney with an eye on the cash register. Locating the wheel on the left was one of Ford's many ruses to make his car as different as possible from the Seldon patent, meaning he could avoid paying royalties.

Incidentally although more people do drive on the right than the left it is closer than is commonly thought about 3.5 billion as opposed to 2.5 billion on the left.

This question was addressed by "Questions, Questions" in its first series.

The Romans appear to have started it. Most people are right-handed and would hold a weapon in their right hands. Therefore, Roman soldiers marched on the left, ready to fight on their right-hand side.

Most countries followed this practice until Napoleon decided that, as the British travelled on the left, it would be better to travel on the right.

Gradually, more countries changed from left to right. I think the Swedes may have been the last (in 1967) in Europe, although (bizarrely) they had left-hand-drive cars, even when they drove on the left.

What's the current position in Australia? There was some talk of them changing to the right, in an effort to stem the tide of Japanese imports.

And another thing: why do ships keep to the right of a channel?

the question should be why do people drive on the right, keeping to the left was the common way of avoiding on-coming traffic until the 18th C then for some reason large chunks of civilisation switched to the right

The way I heard it, Napoleon opted for driving on the right because he was convinced that was the way the Romans drove. The Americans adopted driving on the right because they wanted to emulate the French after France's successful revolution against the monarchy.

That's the way I heard it too, but that does not explain what happened in Sweden back in 1967