drive on right (steering wheel is usually on the left)     drive on left (steering wheel is usually on the right)

Right-hand traffic and left-hand traffic mean regulations requiring all traffic to keep either to the left or the right side of the road.^[1][2] This is so fundamental to transport that it is sometimes referred to as the rule of the road.^[3] The purpose of this basic rule is to facilitate traffic flow and reduce the likelihood of head-on collisions. Though originally most traffic drove on the left worldwide,^[4] today right-hand traffic prevails. About 34% of the world's people live in left-traffic countries and 66% in right-traffic countries; roughly 28% of the world's total road distance carries traffic on the left, and 72% on the right.^[5]

History

Map of the world showing the driving directions for all countries and any changes that have occurred, beginning with Finland's change in 1858
     drives on right      drove on left, now drives on right      drives on left      drove on right, now drives on left      had different rules of the road within borders, now drives on right

The Mishna^[6] records that the Kohanim in the Jewish Temple in Jerusalem would ascend the altar on the east (right) side and descend on the west (left).

In 1998, archaeologists found a well-preserved track leading to a Roman quarry near Swindon, England. The grooves in the road on one side were observed to be much deeper than those on the other side, which would make sense given that carts would be driven without any load on the way to the quarry, but would return laden with stone. These grooves suggest that the Romans drove on the left, at least in this particular location.^[5]

In fact, some (e.g. C. Northcote Parkinson) believe that ancient travellers on horseback generally rode on the left side of the road. As more people are right-handed, horsemen would thus be able to hold the reins with their left hands and keep their right hand free—to offer in friendship to passing riders or to defend themselves with swords, if necessary.^{citation needed}

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 Highway Act 1773 contained a recommendation that horse traffic should remain on the left and this is enshrined in section 78 of the Highway Act 1835.

In the late 1700s, a shift from left to right took place in countries such as the United States, when teamsters started using large freight wagons pulled by several pairs of horses. The wagons had no driver’s seat, so a postilion sat on the left rear horse and held his whip in his right hand. Seated on the left, the driver naturally preferred that other wagons pass him on the left so that he could be sure to keep clear of the wheels of oncoming wagons. He did that by driving on the right side of the road.^{citation needed}

The British, however, kept to the left. They had smaller wagons, and the driver sat on the wagon, usually on the right side of the front seat. From there he could use his long whip in his right hand without entangling it in the cargo behind him. In that position, on the right side of the wagon, the driver could judge the safety margin of overtaking traffic by keeping to the left side of the road. Countries that became part of the British Empire adopted the keep-left rule too, although there were some exceptions. Canada, for example, where the maritime provinces and Vancouver (later to become British Columbia) drove on the left, eventually changed to the right in order to make border crossings to and from the United States easier. Nova Scotia switched to driving on the right on April 15, 1923. During World War II, American truck makers Ford, Chevrolet and Chrysler built 'Canadian Military Pattern' [CMP] trucks for use throughout the British Empire and most were right hand drive to use in left hand traffic countries.

On most early motor vehicles, the driving seat was positioned centrally. Some car manufacturers later chose to place it near the centre of the road to help drivers see oncoming traffic, while others chose to put the driver's seat on the kerb side so that the drivers could avoid damage from walls, hedges, gutters and other obstacles. Eventually the former idea prevailed.

In Europe, the 20th century saw a slow but steady shift from keep-left to keep-right. Portugal switched to the right early in the 20th century. Austria and Czechoslovakia changed to the right when occupied by Nazi Germany at the end of the 1930s, and Hungary followed suit. Sweden changed in 1967 and Iceland in 1968. Today, just four European countries still drive on the left: Cyprus, Ireland, Malta and the United Kingdom. All are island nations, and none shares a border with a country that drives on the right; all were once part of the British Empire.

Terminology

A country's traffic-handedness is most properly designated with reference to the rule of the road, i.e., the side of the road along which traffic flows. Using such a referent, countries are said to have left-hand traffic (LHT) or right-hand traffic (RHT)^{[7] [8][9]}. However, traffic-handedness is sometimes designated with reference to the placement of the steering wheel and driver's seat within vehicles. Using this terminology, countries are said to be left-hand drive (LHD) or right-hand drive (RHD).^[10][11][12] In almost all cases, the placement of the steering wheel is opposite to the rule of the road: LHT countries use RHD vehicles, and RHT countries use LHD vehicles. Confusion can arise from the misuse of LHD and RHD to indicate the side of the road along which vehicles are driven. In addition, there have been markets (such as some Caribbean islands, and Sweden before the change from LHT to RHT in 1967) that use mostly LH-drive vehicles with LH-traffic, or mostly RH-drive vehicles with RH-traffic. In addition, wrong hand-drive vehicles are permitted in many markets.

Right-hand traffic

• Oncoming traffic is seen coming from the left.
• Left-turning traffic must cross oncoming traffic.
• Most traffic signs facing motorists are on the right-hand side of the road.
• Overtaking other vehicles is done by driving on the left.
• Traffic on roundabouts (traffic circles or rotaries) goes anticlockwise (counter-clockwise).
• Pedestrians crossing a two-way road should first look for traffic from their left.
• Most vehicles have a left-hand driver's position, instruments and controls.

Left-hand traffic

A sign on Australia's Great Ocean Road reminding foreign motorists to keep left.

• Oncoming traffic is seen coming on the right.
• Right-turning traffic must cross oncoming traffic.
• Most traffic signs facing motorists are on the left-hand side of the road.
• Overtaking other vehicles is done by driving on the right.
• Traffic on roundabouts (traffic circles or rotaries) goes clockwise.
• Pedestrians crossing a two-way road should first look for traffic from their right.
• Most vehicles have a right-hand driver's position, instruments and controls.

Safety factors

The M1 in Johannesburg, South Africa during rush hour as it passes through the suburb of Sandton. Like most former British colonies in Africa, South Africa drives on the left.

Research in 1969 by J. J. Leeming showed countries driving on the left have a lower collision rate than countries driving on the right. This research is questioned in Peter Kincaid's book on the rule of the road,^{citation needed} but some countries that have switched to driving on the right, such as Sweden), have seen their long-term accident rates increase by more than any increase in traffic volume^{citation needed}. It has been suggested, but not proven, that this is partly because it is more common to be right-eye dominant.^[13][14][15] Traffic flows in a clockwise direction when driving on the left which enables right eyed people to use the right eye to see oncoming traffic. When overtaking (passing) on a right-side-driving road, the right-eyed driver looks in the wing mirror (side mirror) with the left eye and also views the oncoming traffic with the left eye which is not suited to the majority right-eyed people.

Changing sides at borders

The Change of traffic directions at the Laos–Thai border takes place on Lao territory just off the Thai–Lao Friendship Bridge.

Thai-Myanmar friendship bridge.

There are many instances of traffic having to change sides at border crossings, such as at those between Afghanistan and Pakistan, Laos and Thailand, Sudan and Uganda. Thailand is particularly notable in the context of border crossings, as it is the only sizeable country that has nearly all of its borders with countries that drive on the opposite side. It drives on the left, but 90% (4,357 km or 2,707 miles) of its borders are with countries that drive on the right, with only Malaysia driving on the left since Myanmar (Burma) changed from driving on the left to driving on the right in 1970.

Many borders are formed from natural barriers such as mountains or rivers, and this is particularly true of borders where traffic changes sides of the road, especially in Asia. These natural barriers make the number of border crossings much lower than would otherwise be the case. Furthermore, given their remoteness, most mountain border crossings have relatively low traffic volumes and so changing sides of the road is even less of an issue.

The four most common ways of switching traffic from one side to the other at borders are:

• Traffic lights. Examples are:
  • Friendship Bridge between Thailand and Laos, change takes place on Lao side - photo, photo
  • Second Thai–Lao Friendship Bridge, between Thailand and Laos, change takes place on Thai side
  • Friendship Bridge between Thailand and Myanmar - photo
  • New bridge between Thailand and Myanmar (opened in 2006) - photo

• Crossover bridges. Examples are:
  • Lok Ma Chau between Hong Kong and mainland China - Google Maps
  • Lotus Bridge between Macau and mainland China - Google Maps

• Border roads intersect with roundabouts or other one-way traffic systems. Examples are:
  • Man Kam To between Hong Kong and mainland China - Google Maps
  • Land border between Macau and mainland China - Google Maps
  • The Eurotunnel Shuttle service of the Channel Tunnel between the United Kingdom and France - Google Maps and Google Maps

• No automatic infrastructure (signposts and directions only), most commonly found at borders with low traffic volumes. Examples are:
  • Poipet between Thailand and Cambodia - photo, photo
  • Old bridge between Thailand and Myanmar - photo, photo
  • Khunjerab Pass between Pakistan and China - photo

Changing the rule

Prior to World War I, left-hand traffic was found in Hungary, parts of Canada, Czechoslovakia, parts of Austria, Sweden, Iceland, Argentina, Uruguay, Paraguay, parts of Brazil, parts of Chile, parts of Italy, China, the Philippines, and Burma. Italy changed when Benito Mussolini came to power, Austria and Czechoslovakia when Adolf Hitler annexed or occupied them, the Latin American countries by 1945, the Philippines and China in 1946 (leaving Hong Kong and Macau isolated), and Burma/Myanmar in 1970 on the advice of a soothsayer.^[16]

Some Commonwealth countries and other former British colonies, such as Australia, India and South Africa continue to drive on the left, but others such as Canada, Gambia, Ghana, Nigeria, Sierra Leone, and the United States have switched to the right. Other countries where driving is on the left are Thailand, Indonesia and East Timor in Southeast Asia, Suriname, Japan, the U.S. Virgin Islands and Mozambique. Like Hong Kong, Macau's traffic also moves on the left, in contrast with mainland China.

There is a popular story that Napoleon changed the rule of the road in the countries he conquered from keep-left to keep-right. The justifications mentioned are usually symbolic, such as that Napoleon himself was left- (or right-) handed, or that Britain, Napoleon's enemy, kept left. This story has never been shown to have a factual basis and it appears to be a legend.^[17]

The most common reason for countries to switch is for conformity with neighbours, as it increases the safety of cross-border traffic. For example, former British colonies in Africa, such as the Gambia, Sierra Leone, Nigeria, and Ghana, have all changed from left- to right-hand traffic, as they all share borders with former French colonies, which drive on the right. The former Portuguese colony of Mozambique has always driven on the left, since Portugal used to drive on the left until the 1920s. Mozambique didn't change (although Portugal did) as all its neighbours drive on the left, being former British colonies. Decisions by countries to drive on the right typically concern conformity and uniformity rather than practical reasons. There are historical exceptions, such as postilion riders in France, but such historical advantages do not apply to modern road vehicles.

In the former British Crown colony of Hong Kong and the former Portuguese enclave of Macau, traffic continues to drive on the left, unlike in mainland China, despite the fact that they are now its Special Administrative Regions. On the other hand, Taiwan, formerly under Japanese rule, changed to driving on the right in 1946 after the government of the Republic of China assumed administration; the same happened in Korea (both North and South), a former Japanese colony. However, some trains in Seoul, as well as pedestrian traffic in the subway system, still keep to the left.

Foreign occupation and military transit

Many countries have temporarily or permanently changed their rule of the road as a result of foreign occupation. Recent examples include Austria, Czechoslovakia (details) and Hungary under German rule or military transit in the 1930s and 1940s. The Channel Islands also changed to driving on the right under German occupation, but changed back after liberation in 1945. The Falkland Islands did the same under Argentine control during the 1982 Falklands War. East Timor changed to driving on the left under Indonesian rule in 1976, and continues the practice as an independent state. The Japanese region of Okinawa changed from left to right under US control; in 1972 Okinawa was returned to Japanese sovereignty, and six years later, in 1978, the driving rules reverted to left hand traffic as in mainland Japan.

Uniformity

One of many road signs in the English county of Kent placed on the right hand side of the road

Article 9(1) of the United Nations' Geneva Convention on Road Traffic (1949)^[18] requires each country to have a uniform direction of traffic, i.e. each country may have either left-hand traffic or right-hand traffic, but not both:

Before that, a country could have different rules in different parts, for example Canada until the 1920s. Currently China forms an exception to this rule since the incorporation of Hong Kong.

When islands are excluded, the only continents in which the same rule of the road applies over the entire continent are the following:

1. Australia with left-hand traffic.
2. Mainland Europe since Sweden changed to right-hand traffic in 1967.
3. North America, including Central America since Belize changed to right-hand traffic in 1961.

In addition, South Asian countries, which constitutes most of the Indian subcontinent, like India, Pakistan, Bangladesh, Nepal, Sri Lanka and Bhutan have left-hand traffic.

Certain countries in Africa, Asia, and South America have land borders where drivers must change to the other side of the road.

Vehicles

Legal restrictions on wrong-hand drive vehicles

For safety reasons (and in some cases political or economic reasons), some countries have banned the sale or import of vehicles with the steering wheel on the wrong side.

In Australia this is the case with non-vintage (i.e. less than 30 years old) LHD vehicles, with the result that Australians who import such vehicles usually must pay sometimes thousands of dollars to convert them to RHD. The exceptions are for vehicles registered in Western Australia and the Northern Territory - both which have at various times hosted U.S. military facilities and had vehicles imported, used and sold by U.S. service personnel in circulation. The Australian Capital Territory (ACT) previously allowed non-vintage LHD vehicles to be registered, but changed its legislation some years ago.

In India, LHD cars cannot be sold commercially to customers, but they can be imported for research and testing purposes under government approval.^[19]

In New Zealand, LHD vehicles may be privately imported, and driven locally under a LHD permit. Since 1999, only LHD vehicles older than 20 years or cars owned and operated for at least 90 days may be privately imported. Diplomats and Operation Deep Freeze personnel are exempted from these restrictions.

In the Philippines, RHD vehicles especially cars, are banned. Public buses and vans imported from Japan are converted to LHD, and passenger doors are created on the right side. This ban was thought to be the result of the increase of accidents involving RHD vehicles, most of which were trucks. However, some vans keep their doors on the left side, leading to the odd (and dangerous) situation in which passengers have to exit toward oncoming traffic. Some RHD vehicles, like certain industrial cranes, remain.

Cambodia banned the use of RHD cars, many of which were smuggled from Thailand, from 2001, even though RHD vehicles accounted for 80 percent of vehicles in the country. The government threatened to confiscate all such vehicles unless they were converted to LHD, in spite of the considerable expense involved. According to a BBC report,^[20] changing the steering column from right to left would cost between US$600 and US$2,000, in a country where average annual income was less than US$1,000.

A RHD Toyota Landcruiser in front of a Pyongyang hotel

Although it drives on the right, North Korea has imported various used RHD vehicles from Japan, from tourist buses to Toyota Land Cruisers.

However, many used vehicles exported from Japan to countries like Russia and Peru are already converted to LHD. But even if the driver's position is left unchanged, some jurisdictions require at least replacement of the headlamps.

Singapore bans LHD vehicles from being imported for personal local registration, but temporary usage by tourists of LHD vehicles is allowed. However, diplomatic vehicles in Singapore are exempt from the RHD-only ruling, and there are a few hydrogen and fuel cell powered LHD vehicles currently undergoing trials in Singapore.

In Taiwan, Article 39 of the Road Traffic Security Rules (zh:道路交通安全規則) require a steering wheel to be on the left side of a vehicle to pass an inspection when registering the vehicle, so RHD vehicles may not be registered in Taiwan. This rule does not apply retroactively, so a RHD vehicle that was registered before this rule does not lose its registered status and may continue to be legally driven.

In Trinidad and Tobago, LHD vehicles are banned except for returning nationals who were resident in a foreign country and are importing a vehicle for personal use. LHD vehicles are also allowed to be imported for use as funeral hearses.

In West Africa, once-British Ghana and Gambia have also banned RHD vehicles. Their traffic has been changed from on the left to on the right. Ghana prohibited new registrations of RHD vehicles after 1 August 1974, three days before the traffic change on 4 August 1974. RHD vehicles may be imported only temporarily into Sierra Leone, for example for humanitarian programmes, but must be exported at the end of the operation.

Most of the above bans on RHD and LHD vehicles apply only to locally-registered vehicles. Countries that have signed the 1968 Vienna Convention on Road Traffic are not allowed to make such restrictions on foreign-registered vehicles. Paragraph 1 of Annex 5 states "All vehicles in international traffic must meet the technical requirements in force in their country of registration when they first entered into service". Therefore all signatory countries and most non-signatory countries allow the temporary import (e.g. by tourists) of foreign-registered vehicles, no matter which side the steering wheel is on. Oman, which has not signed the convention bans all foreign-registered RHD vehicles.^[21]

Both RHD and LHD vehicles may generally be registered in any European Union member state, but there are some restrictions and regulations. Slovakia, despite being a member of the European Union, does not allow the local registration of RHD vehicles,^[22] even if the vehicle is imported from one of the four EU countries that drive on the left (UK, Ireland, Cyprus, and Malta). Lithuania has prohibited new RHD vehicle registration since 1993.

Headlamps and other lighting equipment

Bird's-eye view of a low-beam headlamp light distribution for right-hand traffic

Most low-beam headlamps are specifically designed for use on one side of the road or the other. Headlamps for use in LH-traffic countries have low-beam headlamps that "dip to the left", i.e., the light is distributed with a downward/leftward bias to show the driver the road and signs ahead without blinding oncoming traffic. Headlamps for RH-traffic countries have low beams that "dip to the right", with most of their light directed downward/rightward. Within Europe, when driving a vehicle with RH-traffic headlamps in a LH-traffic country or vice versa for a limited time (as for example on holiday or in transit), it is a legal requirement to adjust the headlamps temporarily so that the wrong-side hot spot of the beam does not dazzle oncoming drivers. This may be achieved by adhering blackout strips or plastic prismatic lenses to a designated part of the lens, but some varieties of the projector-type headlamp can be made to produce a proper LH- or RH-traffic beam by shifting a lever or other movable element in or on the lamp assembly.

Because blackout strips and adhesive prismatic lenses reduce the safety performance of the headlamps, most countries require all vehicles registered or used on a permanent or semi-permanent basis within the country to be equipped with headlamps designed for the correct traffic-handedness. In the UK, US government and military personnel who brought RHT/LHD cars with them used to 'trade' headlamp assemblies with a person returning to the US^{citation needed}. The newcomer then had proper LHT lights and the US-bound returnee had proper RHT ones again. As most 50s-80s headlamps were interchangeable, this 'swap' could save motorists time and money.

Anecdotal reporters have observed^who? the requirement to adjust headlamps for the traffic-handedness of the country is increasingly flouted, and is now rarely enforced by European police forces. In France, this may be due in part to the 1993 deletion of the previous requirement for selective yellow headlamp light; foreign-registered vehicles are now much less conspicuous at night.

Without sidecars attached, motorcycles, motor scooters, mopeds, and bicycles are almost symmetric with their handlebars in the centre. However, motorcycles are often equipped with automotive-type asymmetrical-beam headlamps that likewise require adjustments or replacement when brought into a country with opposite traffic-handedness.

Rear fog lamps

Within the EU, vehicles must be equipped with one or two red rear fog lamps. A single rear fog lamp may be located on the vehicle centreline, or on the driver's side of the vehicle. It may not be located on the passenger's side of the vehicle. This sometimes requires the purchase and installation of local-market lighting components.

Buses

Comparison of continental door (left) against standard emergency exit door (right) on Plaxton Paramount coaches.

Buses typically have passenger doors only on the kerb side, which severely restricts their ability to operate effectively on the opposite side of the road to that for which they were designed. Increasingly, touring coaches, which are likely to cross frontiers of traffic-handedness during their duties, are fitted with a door on the opposite side from the kerb, to simplify access and egress in the foreign country. In Britain this is known as a "continental door", since its usefulness will be in continental Europe. It doubles as an emergency exit, but is much more user-friendly than an exit designed solely for emergency use.

It is usually fairly straightforward to retrofit a non-kerb-side door on buses with relatively low floor height, for example the many traditional British double-deckers sold on for tourist use in the USA and Canada.

Postal vehicles

Post Office cars and vans in different countries such as the United States, Canada, Finland, Estonia and Sweden have the steering wheel on the opposite side to normal vehicles. This is so the driver can easily drive up next to mailboxes or get out straight onto the pavement without having to walk around their vehicle, or put mail in boxes without getting out of their vehicle at all. In the US, rural mail carriers often must provide their own vehicles and have a limited selection of RHD vehicles that they can choose to buy or lease. Some utility service vehicles are also RHD to allow dismounting at the kerb and some newspaper carriers use RHD vehicles to deliver papers to kerbside boxes rather than drive along routes on the wrong side. The Jeep Wrangler is available in the United States in a RHD configuration, since this particular model is popular with rural mail carriers who sometimes operate in less-than-optimal road conditions and thus appreciate the Wrangler's 4WD capabilities.^{citation needed}

Trains

Train entering the Channel Tunnel from France

Trains may or may not adhere to the same directionality as cars. In France, for instance, cars keep to the right, but the first train lines were built by British engineers, so kept to the left. The Paris RER trains keep left, but have to operate on separate tracks within the Paris Metro area which was designed to run on the right. Another anomaly occurs in the Alsace-Moselle region, where trains keep to the right because the lines were built in the late 19th century when Alsace-Moselle had been part of Germany. Bridges at the former border allow the trains to swap sides. High-speed TGV trains, however, operate on dedicated lines which were built more recently, but they keep left because they interface with older lines. Madrid Metro trains operate also to the left.

Moreover the exceptions of left or right hand driving are much more common for trains than for cars. Initially, most steam engines were RHD, with the driver (engineer) sitting on the right, and the fireman (conductor) sitting on the left. This was customary in the UK and it spread to the USA and elsewhere in the world. RHD was never converted to LHD even if the trains switched to right-hand running. RHD remains the customary way for operating trains, with the driver on the right and assistant, sitting on the left side of the cab. Ironically, some railways, particularly, the London Underground, switched to LHD with left-hand running. Left Hand Drive with left hand running also became common on UK mainline railways, with the Great Western Railway being the only of the "big four" to keep the driver on the right. To ease visibility, GWR signals were also occasionally placed on the right-hand side of the tracks, even though this meant that they were between the running lines, and a few examples of this have managed to survive. Nowadays all British trains (except a few preserved locomotives and a number of narrow-gauge railways) have the driver on the left side of the train, and the signals are also on the left-hand side of the track.

In countries with trains keeping to the right it is often said that RHD is safer, as it is possible that something from a train passing on the left track (like opened cargo doors) may hit the train. In such case driver on the right is safer than if he were sitting to the left. Also, since signs and signals are usually placed on the outside of double track formations (e.g left hand side for left hand running or right hand side for right hand running), having the driver on the side as well makes it easier for them to see signs and signals, and also to view back along the platform either directly or using mirrors, particularly useful with one person operated trains. Finally, if 'train orders' or 'tokens' (permission to continue beyond a station or other control point) are handed-up or grabbed by the engine driver while rolling past, being on the 'outside' is mandatory to receive these 'orders/tokens'...  Unlike on the road, it is possible for trains to safely run on the wrong side so long as bi-directional signalling is installed. This is normally only done in limited circumstances, since junctions and other infrastructure is usually optimised for running in one direction.

Trams (streetcars)

Tram and streetcar systems generally follow the same rules as normal road traffic in the country concerned, both on road and on reserved sections, with the passenger doors on the curb side. Various exceptions existed or have existed, examples including the now-removed system in London and the current system in Blackpool where some sections of tramway had or have both tracks on the same side of the road with no physical separation from road traffic.

The driver is usually positioned near the centre of the vehicle, although some single-operator trams have been developed wherein the driver sits nearer the center of the road. On the left-hand running Blackpool system and Melbourne trams built between the 1970s and 1990s, the driver sits on the right; on the old right-hand drive Zagreb trams, the driver sits on the left.

When Sweden changed to driving on the right, its single-ended trams were found to have the doors on the wrong side, and this was taken as an excuse to scrap the trams.

Ships and boats

Generally all water traffic keeps to the right. This is historically because, prior to the use of a rudder, the boat was steered by a tiller, which was located on the right-hand side, also called starboard side of the boat, because the helmsman, standing in the middle of the boat and looking ahead, used his right hand to operate it. Traditionally, boats would also moor with the left hand side to the quay to prevent damage to the steering oar, and this was referred to as larboard (loading side), later replaced by port to prevent confusion from the similar sounding words. By keeping to the right, boats pass port-to-port, protecting the steering oar. When modern style rudders fixed to the stern were developed, the helmsman was moved amidships (on the centreline), and when wheels replaced tillers this generally remained the same. Many motor yachts and other small craft are RHD, but some boats, typically smaller pleasure craft and wooden 'speedboats' are built LHD, to give a better view of approaching and passing traffic.

However, there are many exceptions, often indicated on the particular bridge itself.^[5]

The rule of the road at sea is that powered vessels give way to sailing vessels; but as between two powered vessels, if they are crossing the rule is to give way to the starboard, while if they are head on each must navigate to starboard so as to pass "port to port". See International Regulations for Preventing Collisions at Sea.

Priority

Main article: Traffic#Priority (right of way)

As well as the side of the road, priority rules also differ between countries. In the United Kingdom, priority is always indicated by signs or road markings, in that almost every junction not governed by traffic lights or a roundabout has a concept of a major road and minor road. In most of Continental Europe, the default priority is to give way to the right, but this default may be overridden by signs on major roads. In Germany, traffic on roundabouts used to have priority, but that rule was abandoned to align with other European countries. Now most roundabouts have give-way signs for traffic entering the roundabout. One special case is the Place de l'Étoile in Paris (the location of the Arc de Triomphe). Traffic on this particular roundabout is so chaotic that French insurance companies deem any accident on the roundabout to be equal liability. British and Irish drivers who are accustomed to having right of way by default unless they are specifically told to give way, are often more confused by the default give-way-to-the-right rule used on minor roads in nearby Continental Europe than they are by switching sides of the road^{citation needed}.

Lanes

Main article: Traffic#Lanes

When driving on the left:

• Overtaking (passing) is on the right if permitted
• The lane designated for normal driving and turning left is on the left
• Most freeway exits are on the left
• Overtaking is in some circumstances permitted on the left. In the UK overtaking on the left (colloquially known as 'undertaking') is not usually permitted, except in certain circumstances, such as when the vehicle being passed is indicating to make a right turn, in a queue of slow-moving traffic, or on a one-way street where all lanes are travelling in one direction. Directives generally require all traffic to keep left unless overtaking. In Australia overtaking on the left is permitted when lane boundaries are marked.
• Turn-to-left after stop is sometimes allowed at stop signs/lights.

When driving on the right:

• Overtaking (passing) is on the left if permitted
• The lane designated for normal driving and turning right is on the right
• Most freeway exits are on the right
• Overtaking is in some circumstances permitted on the right.
• Traffic is required to keep right
• Right turn (in some places after stopping the vehicle) is allowed at intersections
• In most European right-hand drive countries, the lack of turn arrow markings on the pavement implies that the left lane is used by left-turning traffic, the right lane by traffic going straight and turning right and all others lanes for going straight. Such rules in USA vary between the states
• The driver should give way to the incoming vehicle on the right

Places with right-hand traffic

List of places where traffic keeps right 

This section needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (January 2008)

Note: Italics indicates year of change to driving on the right.

Afghanistan Albania Algeria American Samoa Andorra Angola (1928) Argentina (1945) Armenia Aruba Austria (1935-38) Azerbaijan Bahrain (1967) Belarus Belgium Belize (1961) Benin Bolivia Bosnia and Herzegovina Brazil British Indian Ocean Territory Bulgaria Burkina Faso Burundi Cambodia Cameroon (1961) Canada (1920s) Cape Verde (1928) Central African Republic Chad Chile China, mainland (1946) Colombia Comoros Congo (Brazzaville) Congo (Kinsasha) Costa Rica Côte d'Ivoire Croatia Cuba Czech Republic (1939, details) Denmark 1793*

Djibouti Dominican Republic Ecuador Egypt El Salvador Equatorial Guinea Eritrea (1964) Estonia Ethiopia (1964) Faroe Islands Finland (1858) France (1789) French Guiana French Polynesia Gabon Gambia (1965) Georgia Germany Ghana (1974) Gibraltar (1929) Greece Greenland Guadeloupe Guam Guatemala Guinea Guinea-Bissau (1928) Haiti Honduras Hungary (1941) Iceland (1968) Iran Iraq Israel Italy Jordan Kazakhstan Korea DPR Korea (1946) Kuwait Kyrgyzstan Laos

Latvia Lebanon Liberia Libya Liechtenstein Lithuania Luxembourg Madagascar Mali Marshall Islands Martinique Mauritania Mayotte Mexico Micronesia Midway Atoll Moldova Monaco Mongolia Montenegro Morocco Myanmar (1970) Netherlands Netherlands Antilles New Caledonia Nicaragua Niger Nigeria (1972) Northern Mariana Is. Norway Oman Palau Panama (1943) Paraguay (1945) Peru Philippines (1946) Poland Portugal (1928) Puerto Rico Qatar Republic of Macedonia Réunion

Romania Russia Rwanda Saint Pierre and Miquelon Samoa (1960s) San Marino São Tomé and Príncipe (1928) Saudi Arabia Senegal Serbia Sierra Leone (1971) Slovakia (1939-41, details) Slovenia Somalia (1968) Spain (October 1924) Sudan (1973) Svalbard Sweden (1967, details) Switzerland Syria Taiwan (1946) Tajikistan Togo Tunisia Turkey Turkmenistan Ukraine United Arab Emirates United States (1792) Uruguay (1945) Uzbekistan Vanuatu Vatican City Venezuela Vietnam Wake Island Wallis and Futuna Western Sahara Yemen(1977)*

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*1758 in Copenhagen, 1793 in the rest of Denmark
**In South Yemen

Total: 164 countries

Places with left-hand traffic

List of places where traffic keeps left 

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Note: Italics indicates year of change to driving on the left.

Alderney Anguilla Antigua and Barbuda Australia Bahamas Bangladesh Barbados Bermuda Bhutan Botswana Brunei Cayman Islands Christmas Island Cocos (Keeling) Islands Cook Islands Cyprus Dominica East Timor (drove on right 1928-1976) Falkland Islands Fiji Grenada Guernsey Guyana Hong Kong, China - unlike mainland China India

Indonesia* Ireland Isle of Man Jamaica Japan (Okinawa 1978) Jersey Kenya Kiribati Lesotho Macau, China - unlike mainland China Malawi Malaysia Maldives Malta Mauritius Montserrat Mozambique Namibia (1918) Nauru (1918) Nepal New Zealand Niue Norfolk Island Pakistan Papua New Guinea

Pitcairn Islands Saint Helena Saint Kitts and Nevis Saint Lucia Saint Vincent and the Grenadines Seychelles Singapore Solomon Islands South Africa Sri Lanka Suriname Swaziland Tanzania Thailand Tokelau Tonga Trinidad and Tobago Turks and Caicos Islands Tuvalu Uganda United Kingdom British Virgin Islands U.S. Virgin Islands - unlike rest of U.S. Zambia Zimbabwe

* Until late 1960s, imported vehicles from USA were fitted with left-hand drive layout

Total: 75 countries

Specific jurisdictions

Afghanistan

Afghanistan drives on the right. Most vehicles in much of the country, however, are RHD cars imported from neighbouring Pakistan (with the exception of Herat and other western provinces). In the capital Kabul, most drivers have adapted to this problem, leaning over the passenger seat (on the car's left side) before making a left turn or before overtaking other vehicles by veering into the left (oncoming traffic) lane. The country also has a large volume of military vehicle traffic from the U.S., Canada and EU militaries, much of which is LHD.

Australia

Australia drives on the left. The decision to drive on the left side of the road was given by Gov. Macquarie in the early 19th century after he had built the first road. This was chosen to align New South Wales with the United Kingdom. Australian states and territories use the "give way to the right" rule; in the absence of regulations specific to a particular situation, a driver must yield the right of way to all vehicles to her right.^[23].

Austria-Hungary

The Austro-Hungarian Empire drove on the left. Successor countries switched to the right separately. Austria did it in stages, beginning from the west:

• Vorarlberg: 1919,
• Tirol and western half of Salzburg: 1930,
• Carinthia and East Tirol: 1935,
• Upper Austria, Styria, eastern half of Salzburg: June 1, 1938,
• Lower Austria: September 19, 1938.

Poland's Galicia switched to the right around 1924. Czechoslovakia planned to start driving on the right on May 1, 1939, but the change in Bohemia and Moravia was prompted by the German occupation forces (Bohemia: March 26, 1939). Hungary also acted later than planned: the government decided about the change in June 1939 but postponed it and finally introduced it at 3am on 6 July 1941 outside Budapest and at 3am on 9 November 1941 in Budapest.

Burma (Myanmar)

As a former British colony, cars in Burma (Myanmar) drove on the left side until 1970, when the military administration of Ne Win decreed that traffic would drive on the right side of the road. It is alleged that this was because Ne Win had been advised by his soothsayer, who had said "move to the right".^[24] In spite of the change, most passenger vehicles in the country today are RHD, being second-hand vehicles imported from Japan, Thailand, and Singapore. Buses imported from Japan that were never converted from RHD to LHD, have doors on the right side in offset position, unlike their counterparts in the Philippines. However, government limousines, imported from the People's Republic of China, are LHD. Virtually all vehicles are driven with a passenger in place to watch the oncoming traffic and inform the driver as to whether it is safe to overtake or not, as the driver cannot see this from the RHD position.

Canada

Until the 1920s, the rule of the road in Canada varied by province, with British Columbia, New Brunswick, Nova Scotia, and Prince Edward Island having cars driving on the left, and the other provinces and territories having motorists driving on the right. Starting with inland British Columbia on 15 July 1920 and ending with Prince Edward Island on 1 May 1924, these provinces changed to driving on the right. Newfoundland was not part of Canada until 1949, and its motorists drove on the left until 2 January 1947.^[25]

Some RHD vehicles can be found, particularly smaller Canada Post service trucks. These have extra mirrors to increase driver visibility. A few other vehicles, such as some garbage trucks or street cleaners may have dual LHD and RHD. The advantage of such arrangements is that the driver can hop in and out of the vehicle easily, and more easily observe their actions at the kerbside.

RHD vehicles are allowed for import in Canada, providing that they were manufactured over 15 years ago. For instance, before Rolls-Royces were marketed in Canada, the only imports available were RHD. Recently, however, Rolls-Royce and other expensive British automakers now manufacture LHD versions and have a Canadian office. Some Japanese RHD cars can be found as well, like the Nissan Skyline, Mitsubishi Delica and Mitsubishi Pajero. These cars are mainly found in British Columbia due to the proximity to Asian ports, but may also be found in cities such as Calgary, Toronto and Saskatoon.

One of the very few places in Canada where traffic drives on the left is in Montreal on Autoroute 20 for the 3 kilometers (2 mi) between its junctions with Route 138 and Autoroute 15. The two roadways remain separated by a concrete median barrier for this entire distance and the changing of sides does not interfere in any way with the flow of traffic.

Caribbean

The English-speaking Caribbean typically follows the keep-to-the-left rule and as a result, most cars have a RHD configuration. Examples of this may be noted in such countries as Barbados, Jamaica and Trinidad & Tobago. In certain islands such as the British Virgin Islands, U.S. Virgin Islands, the Cayman Islands, the Bahamas, as well as Turks and Caicos Islands, most passenger cars are LHD, being imported from the United States or Brazil.^[26] Only some government cars and those imported from RHD countries (Japan and the United Kingdom among others) are RHD. The U.S. Virgin Islands are particularly known for having a high accident rate caused by American tourists from the mainland who are unfamiliar with driving on the left in their rental cars.

China (mainland)

Until 1946, driving in mainland China was mixed, with cars in the northern provinces driving on the right (probably to concur with Russian practice, which was "keep right" from 1920), and cars in the southern provinces such as Guangdong driving on the left, probably a result of their proximity to the British crown colony of Hong Kong and the Portuguese enclave of Macau.^{citation needed}

After 1946, China followed the United States, by changing to driving on the right, possibly due to political reasons that the United States helped China to fight against Japanese occupation during World War II and American cars (mostly LHD) were already popular in the mainland.^{citation needed} This rule was also used in Taiwan after the Republic of China took over Taiwan from the Empire of Japan after World War II.^{citation needed}

During the Cultural Revolution (1966-1976), Red Guards in some cities considered that to drive on the right side of road was to take the "rightist's route/policy", and they were said to have ordered vehicles to drive on the left side.^{citation needed} Some also attempted to reverse the traditional meaning of traffic signals by having the red light mean "go" and the green light "stop".^{citation needed} These two changes caused a great deal of confusion and resistance so both were abolished within several months.^{citation needed}

Croatia

Croatia was part of the Austro Hungarian Empire at the beginning of the last century, and after the collapse of the empire, it started driving on the right. Sometimes, on parking garage entrances of the left side of a one-way street the lanes on the entrance are reversed to provide for unrestricted flow of traffic between the garage and the street. One such example is the Importanne Gallery parking garage.^[27] This was done so the traffic lanes in the one way street from which one enters the garage would not cross.

Cyprus

A former British colony, Cyprus drives on the left, and cars sold locally are right hand drive, including those used by the British forces in the Sovereign Base Areas of Akrotiri and Dhekelia. However, owing to its economic and political isolation, there is a sizable number of left-hand drive vehicles in the self-proclaimed Turkish Republic of Northern Cyprus which were imported from Turkey. However, the number of such vehicles is rapidly decreasing due to a 2006 law banning the import of left-hand drive vehicles.^[28] An increasing number of right hand drive grey import vehicles from Japan are now sold in both parts of the island.

France

Along the 350 metres of Avenue du Général Lemonnier in Paris, which connects the Pont Royal to the Rue de Rivoli, traffic drives on the left, separated only by a raised hump - photo, photo

Gibraltar

Although the British overseas territory of Gibraltar changed to driving on the right on 16 June 1929, in order to avoid accidents involving vehicles from Spain, some public buses until recently were RHD, with a special door allowing passengers to enter on the right hand side. However, most passenger cars are LHD, as in Spain, with the exception of second-hand cars brought in from the UK and Japan and some vehicles used by the British forces.

Guyana and Suriname

Guyana and Suriname are the only two remaining countries in the mainland Americas that still drive on the left. As a result of the construction of the Pan-American Highway, four mainland American countries switched to driving on the right between 1943 and 1961, the last of which was Belize. Both Guyana and Suriname are separated from their neighbours by large rivers, over which no road bridges have yet been built. The inland south of both countries is sparsely populated with very few roads and hence no border crossings.

However, in the south west of Guyana near Lethem, work is under way to build the Takutu River Bridge^[29] across the Takutu River into neighbouring Brazil, which drives on the right. Unlike road bridges between other countries that drive on opposite sides of the road, the changeover system will be in the country that drives on the left, i.e. Guyana, where one lane will pass under the other on the bridge's access road. Despite stalling construction in recent years, Brazil is keen to open the bridge, as it will give Brazil access to Caribbean sea ports on the north coast of South America. Brazil intends to permit Guyana registered (RHD) vehicles to go no further than the Braz