It is possible that the custom of driving on the left dates back to pre-history and may later have been used as an early road safety measure. At a time when the main danger on the roads was mugging, careful travellers would pass on-coming strangers on the left with their sword arm towards the passer-by.
The keep left rule did not become law in Britain until the increase in horse traffic made some sort of enforcement essential. Before this, the drivers of coaches leaving London for the country simply chose the firmest part of the road. The main dates for the introduction of the legal requirement to keep left are:
- 1756 – London Bridge
- 1772 – Towns in Scotland
- 1835 – All roads in Great Britain and Ireland
In Europe, Pope Boniface VIII instructed pilgrims to keep to the left in the year 1300. Later, class distinction in France meant that aristocrats drove their carriages on the left side of the road forcing everybody else over to the centre or to the right-hand side. Keeping left had really only ever applied to riding or driving. With the onset of the French Revolution in 1789 and the subsequent declaration of the rights of man in 1791 many aristocrats decided to keep to the ‘poor side’ of the road so as not to draw attention to themselves. Keeping to the right of the road was also seen as a way of defying the earlier Papal decree.
The subsequent Revolutionary wars and Napoleon’s European conquests led to the spread of driving on the right to Switzerland, Germany, Italy, Poland, Spain, Belgium and the Netherlands. Napoleon ordered his armies to use the right-hand side of the road in order to avoid congestion during military manoeuvres. The nations that resisted invasion – Britain, the Austro-Hungarian Empire, Russia and Portugal – generally kept to the left.
The Netherlands changed to driving on the right in 1795, but Dutch colonies in the Far East continued the old practices. Denmark had not been invaded by the French but changed in 1793. Russia did not switch until 1916. Czechoslovakia and Hungary were the last countries in mainland Europe to keep left, only changing to the right following invasion by Germany in the late 1930s.
Portugal made the change from left to right in the 1920s; countries with border crossings found there was great confusion if drivers were required to change sides of the road when passing from country to country. Sweden remained on the left until 1967 and changed to the right following a lengthy road safety campaign.
In Austria from 1805 to 1939 half the country drove on the left whilst the other half, the area that had been invaded by Napoleon, drove on the right!
Most of the British Empire adopted the British custom of driving on the left although Egypt, which had been conquered by Napoleon, kept using the right after it became a British dependency.
Pakistan considered changing from left to right in the 1960s. The main argument against was that camel trains often drove through the night while their drivers dozed. The difficulty in teaching old camels new tricks was a decisive factor in Pakistan rejecting the change.
Canada stayed on the left until the 1920s. During the American War of Independence, French liberal reformer General Lafayette gave advice to the revolutionary forces and spread the idea of driving on the right. The keep right rule was applied to the Pennsylvania turnpike in 1792, New York in 1804 and New Jersey in 1813.
Bucking the normal trend, the Pacific island of Samoa made the switch from driving on the right to driving on the left side of the road on 7 September 2009. The official reason given was so as to fall in line with near neighbours Australia and New Zealand which, like Britain, still drive on the left.
