An interesting look at why we drive on 'our' side of the road, courtesy of the worldstandards website...
"About a 35% of the world population drives on the left, and the countries that do are mostly old British colonies. This strange quirk perplexes the rest of the world, but there is a perfectly good reason.
In the past, almost everybody travelled on the left side of the road because that was the most sensible option for feudal, violent societies. Since most people are right-handed, swordsmen preferred to keep to the left in order to have their right arm nearer to an opponent and their scabbard further from him. Moreover, it reduced the chance of the scabbard (worn on the left) hitting other people.
Furthermore, a right-handed person finds it easier to mount a horse from the left side of the horse, and it would be very difficult to do otherwise if wearing a sword (which would be worn on the left). It is safer to mount and dismount towards the side of the road, rather than in the middle of traffic, so if one mounts on the left, then the horse should be ridden on the left side of the road.
In the late 1700s, however, teamsters in France and the United States began hauling farm products in big wagons pulled by several pairs of horses. These wagons had no driver’s seat; instead the driver sat on the left rear horse, so he could keep his right arm free to lash the team. Since he was sitting on the left, he naturally wanted everybody to pass on the left so he could look down and make sure he kept clear of the oncoming wagon’s wheels. Therefore he kept to the right side of the road.
The French Revolution of 1789 gave a huge impetus to right-hand travel in Europe. Before the Revolution, the aristocracy travelled on the left of the road, forcing the peasantry over to the right, but after the storming of the Bastille and the subsequent events, aristocrats preferred to keep a low profile and joined the peasants on the right. An official keep-right rule was introduced in Paris in 1794, more or less parallel to Denmark, where driving on the right had been made compulsory in 1793.
Later, Napoleon’s conquests spread the new rightism to the Low Countries (Belgium, the Netherlands and Luxembourg), Switzerland, Germany, Poland and many parts of Spain and Italy. The states that had resisted Napoleon kept left – Britain, the Austro-Hungarian Empire and Portugal. This European division, between the left- and right-hand nations would remain fixed for more than 100 years, until after the First World War.The trend among nations over the years has been toward driving on the right, but Britain has done its best to stave off global homogenisation. With the expansion of travel and road building in the 1800s, traffic regulations were made in every country. Left-hand driving was made mandatory in Britain in 1835. Countries which were part of the British Empire followed suit. This is why to this very day, India, Australasia and the former British colonies in Africa go left. An exception to the rule, however, is Egypt, which had been conquered by Napoleon before becoming a British dependency.
Japan was never part of the British Empire, but its traffic also goes to the left. Although the origin of this habit goes back to the Edo period (1603-1868), it wasn’t until 1872 that this unwritten rule became more or less official. That was the year when Japan’s first railway was introduced, built with technical aid from the British. Gradually, a massive network of railways and tram tracks was built, and of course all trains and trams drove on the left-hand side.
In the early years of English colonisation of North America, English driving customs were followed and the colonies drove on the left. After gaining independence from England, however, they were anxious to cast off all remaining links with their British colonial past and gradually changed to right-hand driving. Incidentally, the influence of other European immigrants, especially the French, should not be underestimated. The first law requiring drivers to keep right was passed in Pennsylvania in 1792, and similar laws were passed in New York in 1804 and New Jersey in 1813.
Despite the developments in the US, some parts of Canada continued to drive on the left until shortly after the Second World War. The territory controlled by the French (from Quebec to Louisiana) drove on the right, but the territory occupied by the English (British Columbia, New Brunswick, Nova Scotia, Prince Edward Island and Newfoundland) kept left. British Columbia and the Atlantic provinces switched to the right in the 1920s in order to conform with the rest of Canada and the USA. Newfoundland drove on the left until 1947, and joined Canada in 1949.
When the Nazis marched into Austria on 12 March 1938, Hitler ordered all of Austria to switch to driving on the right.The break-up of the Austro-Hungarian Empire caused no change: Czechoslovakia, Yugoslavia and Hungary continued to drive on the left. Austria itself was something of a curiosity. Half the country drove on the left and half on the right. Not surprisingly, the dividing line was precisely the area affected by Napoleon’s conquests in 1805.
Meanwhile, the power of the right kept growing steadily. American cars were designed to be driven on the right by locating the drivers’ controls on the vehicle’s left side. With the mass production of reliable and economical cars in the United States, initial exports used the same design, and out of necessity many countries changed their rule of the road.
In the 1960s, Great Britain also considered changing, but the country’s conservative powers did everything they could to nip the proposal in the bud. Furthermore, the fact that it would cost billions of pounds to change everything round was not much of an incentive. Eventually, Britain dropped the idea. Today, only four European countries still drive on the left: the United Kingdom, Ireland, Cyprus and Malta."