The origins of driving on the right or left hand side of the road are believed to date back to the middle ages.
What it means is that as a result today more than 60% of countries now have right hand traffic and around 40% drive on the left.
In some of these countries the rules decrees right or left hand drive and no exceptions are allowed. Because there are so many countries which have leftdrive, the demand for left hand drive is so much greater.
There are some seventy six countries where vehicles drive on the left hand side of the road. The most important is the United Kingdom which in the late 19th century was at the forefront of car development , the UK pioneered right drive cars designed to drive on the left of the road.
Because of the lasting influence of the British Empire many commonwealth countries still drive on the left hand side of the road today. These include Australia, New Zealand, India, Bangladesh, Sri Lanka, Malaysia and South Africa. Interestingly this has meant that while in mainland China people drive on the right hand side of the road in the former British colonies of Hong Kong and Macau people still drive on the left.
Almost all Pacific nations drive on the left hand side of the road, and in 2009 Samoa joined these left hand side driving countries. This is quite the rarity as before that it had been almost three decades since anyway else had decided to switch sides. Asian countries including Thailand, Indonesia and Japan also drive on the left hand side of the road. Thanks to Japans adoption of left hand side traffic many of its second hand cars end up in left hand driving countries such as the UK, Australia and New Zealand. This helps to account for the seeming overabundance of Japanese cars you see in those countries.
Probably the most problematic situations occur when the left hand driving country borders a right hand driving country. In parts of Africa, Asia and South America there are land borders where the uniform traffic side switches. Traffic lights and crossover bridges are employed in order to switch over the flow of traffic between the neighbouring countries.
One of the most interesting situations occurred in Japan where the island of Okinawa was occupied by the US Military. Because of this the people were forced to adopt right hand driving even though the rest of the country drove on the left. This lasted until 1978 when Okinawa switched to driving on the left like the rest of the population.
In Europe, Sweden, surrounded by countries with vehicles which drove on the rhs of the road likewise elected to drive on the right side in 1967, the last country on the European continent to do so. The timing of the changeover was early morning when there would have been little traffic, but would still have been exciting as cars switched from one side of the road to the other.
Driving on the left hand side is common practice in many of the world’s nations. Whilst right hand traffic is in the majority, it is good to be aware of which countries drive on the left. Being aware of a change in uniform traffic flow can help prevent a nasty accident when abroad.
All countries, whether they adopt right hand or left hand traffic, require by law that vehicles follow a uniform traffic flow. The obvious advantage of this is that it prevents head on collisions. The less obvious advantage is that it promotes the free and steady flow of traffic.
In countries that require people to drive on the left hand side of the road, the configuration of the cars are built to match. The important differences between right and left side cars include where the steering wheel is placed and where the controls in the car are to be found. The reason that is important to change the configuration of the steering wheel is so that the driver is positioned to have the longest line of sight when overtaking.