Left- and right-hand traffic
[4] While many of the countries using LHT were part of the British Empire, others such as Indonesia, Japan, Nepal, Bhutan, Macao, Thailand, Mozambique and Suriname were not.
Historical switches of traffic handedness have often been motivated by factors such as changes in political administration, a desire for uniformity within a country or with neighboring states, or availability and affordability of vehicles.
In LHT, traffic keeps left and cars usually have the steering wheel on the right (RHD: right-hand drive) and roundabouts circulate clockwise.
RHT is the opposite: traffic keeps right, the driver usually sits on the left side of the car (LHD: left-hand drive), and roundabouts circulate anticlockwise.
Countries in these areas include Mali, Mauritania, Ivory Coast, Burkina Faso, Benin, Niger, Morocco, Algeria, and Tunisia.
In the late 18th century, right-hand traffic started to be introduced in the United States based on teamsters' use of large freight wagons pulled by several pairs of horses and without a driver's seat; the (typically right-handed) postilion held his whip in his right hand and thus sat on the left rear horse, and therefore preferred other wagons passing on the left so that he would have a clear view of other vehicles.
[9][better source needed] The first keep-right law for driving in the United States was passed in 1792 and applied to the Philadelphia and Lancaster Turnpike.
[14] The province of British Columbia changed to RHT in stages from 1920 to 1923,[15][16] New Brunswick, Nova Scotia, and Prince Edward Island in 1922, 1923, and 1924 respectively,[17] and the Dominion of Newfoundland (part of Canada since 1949)[18] in 1947, in order to allow traffic (without side switch) to or from the United States.
[19] In the West Indies, colonies and territories drive on the same side as their parent countries, except for the United States Virgin Islands.
[24] Other Central and South American countries that later switched from LHT to RHT include Argentina,[25] Chile, Panama,[26] Paraguay,[27] and Uruguay.
Although this practice goes back to the Edo period (1603–1868), it was not until 1872 – the year Japan's first railway was introduced, built with technical aid from the British – that this unwritten rule received official acknowledgment.
Post-World War II Okinawa was ruled by the United States Civil Administration of the Ryukyu Islands until 1972, and was RHT until 6 a.m. the morning of 30 July 1978, when it switched back to LHT.
[43] In a study of the ancient traffic system of Pompeii, Eric Poehler was able to show that drivers of carts drove in the middle of the road whenever possible.
[50] An oft-repeated story is that Napoleon changed the custom from LHT to RHT in France and the countries he conquered after the French Revolution.
[update][4] In 1827, long after Napoleon's reign, Edward Planta wrote that, in Paris, "The coachmen have no established rule by which they drive on the right or left of the road, but they cross and jostle one another without ceremony.
In the late 1960s, the British Department for Transport considered switching to RHT, but declared it unsafe and too costly for such a built-up nation.
[69] Today, four countries in Europe continue to use LHT, all island nations: the United Kingdom, Republic of Ireland (formerly part of the UK), Cyprus and Malta (both former British colonies).
[70] Samoa, a former German colony, had been RHT for more than a century, but switched to LHT in 2009,[71] making it the first territory in almost 30 years to change sides.
[72] The move was legislated in 2008 to allow Samoans to use cheaper vehicles imported from Australia, New Zealand, or Japan, and to harmonise with other South Pacific nations.
[74] The motor industry was also opposed, as 14,000 of Samoa's 18,000 vehicles were designed for RHT and the government refused to meet the cost of conversion.
[76] The change included a three-day ban on alcohol sales, while police mounted dozens of checkpoints, warning drivers to drive slowly.
[3] Rwanda and Burundi, former Belgian colonies in Central Africa, are RHT but are considering switching to LHT[77][78] like neighbouring members of the East African Community (EAC).
Reasons cited were the perceived lower costs of RHD vehicles, easier maintenance and the political benefit of harmonising traffic regulations with other EAC countries.
The Takutu River Bridge (which links LHT Guyana and RHT Brazil[86]) is the only border in the Americas where traffic changes sides.
"[89] By 1915 other manufacturers followed Ford's lead, due to the popularity of the Model T.[10] In specialised cases, the driver will sit on the nearside, or curbside.
In some cases, the manufacturer's dashboard design incorporates blanks and modular components, which permits the controls and underlying electronics to be rearranged to suit the right-hand drive model.
[97]: p.13 ¶5.8.1 Some varieties of the projector-type headlamp can be fully adjusted to produce a proper LHT or RHT beam by shifting a lever or other movable element in or on the lamp assembly.
Examples include: Argentina, Belgium, Bolivia, Cambodia, China, Egypt, France, Iraq, Israel, Italy, Laos, Monaco, Morocco, Myanmar, Nigeria, Peru, Portugal, Senegal, Slovenia, Sweden, Switzerland, Taiwan, Tunisia, Uruguay and Venezuela.
Some systems where the metro matches the side of the national rail network but not the roads include those in Bilbao, Buenos Aires, Cairo, Catania, Jakarta, Lisbon, Lyon, Naples, and Rome.
The former Rochester subway, that operated from 1927 to 1956 ran on the left to let unidirectional vehicles with doors on the right use stations with island platforms.
