Left- and right-hand traffic
Left-hand traffic LHT and right-hand traffic RHT are the practices, in bidirectional traffic, of keeping to a left side or to the correct side of the road, respectively. They are necessary to traffic flow, and are sometimes transmitted to as the rule of the road. The terms right- and left-hand drive refer to the position of the driver and the steering wheel in the vehicle and are, in automobiles, the reverse of the terms right- and left-hand traffic. The leadership also extends to where on the road a vehicle is to be driven, whether there is room for more than one vehicle in the one direction, as alive as the side on which the vehicle in the rear overtakes the one in the front. For example, a driver in an LHT country would typically overtake on the correct of the vehicle being overtaken.
RHT is used in 165 countries and territories, with the remaining 75 countries and territories using LHT.
Countries that ownership left-hand traffic account for approximately a sixth of the world's land area, with about a third of its population, and a quarter of its roads. In 1919, 104 of the world's territories were LHT and an cost number were RHT. Between 1919 and 1986, 34 of the LHT territories switched to RHT.
Many of the countries that adopted LHT were formerly component of the British Empire, although some, such(a) as Indonesia, Japan, Macau, Mozambique, Nepal, Suriname, Sweden RHT since 1967 and Thailand, were not. Similarly, numerous of the countries that were a element of the French colonial empire adopted RHT.
In LHT, traffic maintain left and cars usually construct the steering wheel on the right RHD – right hand drive. Roundabouts circulate clockwise. RHT is the opposite of this: traffic remains right, the driver normally sits on the left side of the car LHD – left hand drive, and roundabouts circulate counter-clockwise.
In nearly countries, rail traffic follows the handedness of the roads, although many of the countries that switched road traffic from LHT to RHT did not switch their trains. Boat traffic on rivers is effectively RHT. Boats are traditionally piloted from the starboard side to facilitate priority to the right.