Driving on the left

From Wikinfo

In organized traffic, vehicles going in opposite directions are separated to either the left or right side of the road so they will not block each other's way. By all vehicles keeping to either the left or right, vehicles travelling in opposite directions will not run into each other. This is so fundamental that it is sometimes known simply as the rule of the road. About 34% of the world by population drives on the left, and 66% keeps right. By roadway kilometers, about 28% drive on the left, and 72% on the right.

In more complex traffic situations such as cities, this concept is further extended: some streets are marked as being one-way streets, and on those streets all traffic must flow in only one direction. A driver wishing to reach a destination already passed must use other streets in order to return.

General facts

In areas where traffic keeps to the left:

Oncoming traffic is seen on the right side
Right-turning traffic must cross oncoming traffic
Most traffic signs facing motorists are on the left side of the road
Roundabouts have to be taken clockwise
Pedestrians crossing a two-way road should watch out for traffic from the right first
The driver's seat is usually on the right side of the vehicle, hence the designation right hand drive (RHD).

Advantages

With a right-hand-drive car, given that 90% of the people are right-handed, the less coordinated hand is used for changing gear and operating dashboard controls, leaving the more coordinated right hand free to steer. Driving on the left avoids the difficult combination of steering with the left hand, changing gear with the right hand, and at the same time viewing the oncoming traffic with the left eye.
Approximately two-third of the population is right-eye dominant. When driving on the left, right-eyed people can use their dominant eye to see oncoming traffic. When overtaking on a right-hand-driving road the right-eyed driver looks in the outside mirror with the left eye and also views the oncoming traffic with the left eye, which is not suited to the majority of the right-eyed people.
When reversing and looking over one's shoulder, the driver is able to keep the more coordinated right hand on the steering wheel in a right hand drive car. This also enables easier viewing through the rear window.
When driving on the left, right-handed people, who find it easier to put their right leg over the bicycle, mount bicycles from the kerb. This keeps 90% of the bicycle riders out of the stream of traffic while mounting.
Research in 1969 by J.J. Leeming showed that countries that drove on the left had a lower accident rate than countries that drove on the right. Some countries that have switched to driving on the right (for example Sweden) saw their long term accident rates increase by more than any increase in traffic volumes. However, the evidence from the Swedish experience is diluted by the fact that, prior to the changeover from driving on the left to driving on the right, almost all Swedish vehicles had already been left-hand drive!

Supporting arguments

In other fields of every day life there's a significant number of occurences of working from left to right, too.

Most of the world's languages are read and written from left to right.
In most self-service restaurants, the line starts at the left, and the cash desk is at the right end.

History

In most early motor vehicles the driving seat was in the middle. Later some carmakers chose to have it nearest the centre of the road to help drivers look out for oncoming traffic, whilst others chose to put the seat on the other side so that the drivers could avoid damaging their vehicles on walls, hedges, roadside gutters and other obstacles. Eventually the former idea prevailed.

The need to be ready for self-defence on rural roads inclined most right-handed horseriders to keep to their left when encountering oncoming wayfarers, so as to be able to deploy a sword or other handweapon more swiftly and effectively should the need arise. Also, those on foot and in charge of horsedrawn vehicles would more usually hold the animals' heads with their right hand, and thus walk along the left hand side of the road.

The first legal reference in Britain to an order for traffic to remain on the left occurred in 1756 with regard to London Bridge. The General Highways Act of 1773 contained a recommendation that horse traffic should remain on the left and this was enshrined in the Highways Bill in 1835.