Why do countries drive on the right?

Most countries drive on the right because of historical shifts in the 18th to 20th centuries shaped by French and American influence, the practicalities of horse-drawn freight, the global spread of left-hand-drive cars, and a push for regional consistency. Over time, these forces created a dominant right-hand-traffic norm across Europe, the Americas, and much of Asia and Africa, while left-hand systems persisted where British influence (and later Japan’s) was strongest.

From left-leaning roads to right-hand rules

In medieval Europe, travelers commonly kept left so that right-handed riders could keep their sword arm toward oncoming strangers and mount or dismount safely at the roadside. That started changing in the late 18th century as freight wagons pulled by large teams became common: drivers often stood or rode on the left side of the team, which made it easier and safer to keep to the right so they could judge passing distances. Revolutionary-era France formalized keep-right practices, and Napoleonic rule exported that norm across much of continental Europe. Meanwhile, early U.S. states adopted keep-right laws in the late 1700s and early 1800s, reinforcing the pattern across the Americas.

The role of industrialization and car design

Industrial mass production locked in habits. When Henry Ford put the steering wheel on the left in the Model T (1908), it optimized visibility for right-hand traffic and set a powerful global precedent. As the U.S. and later continental European makers exported vehicles, countries found it cheaper and simpler to match their road rules to the dominant vehicle configurations available to them. Over the 20th century, traffic engineering standards, road signage, and driver training reinforced the benefits of aligning with neighbors. International law does not dictate a side: the 1968 Vienna Convention on Road Traffic harmonizes rules but lets each country choose left or right, so regional economics and history do most of the deciding.

What pushes countries toward the right

Several overlapping forces explain why right-hand traffic became the global majority and why many countries aligned with it over time.

• Political and military influence: French Revolutionary and Napoleonic policies spread keep-right norms across Europe.
• Neighbor alignment: Cross-border trade and shared roads make it practical to drive the same side as adjacent countries.
• Vehicle supply chains: Access to affordable left-hand-drive imports (historically from the U.S. and mainland Europe) nudged countries toward right-hand traffic.
• Urbanization and engineering: Modern road design, signage, and driver training favor consistency; switching can reduce cross-border confusion.
• Cultural-economic gravity: American industry, later joined by European makers, popularized left-hand-drive layouts that favor right-side traffic.

Taken together, these factors created a path-dependent system: once a region leaned right, it became costly and impractical to diverge, cementing the right-hand majority.

When nations switched sides

Changing sides is complex and rare, but several countries did so in the 20th century to improve safety, match neighbors, or access cheaper vehicle fleets.

• Sweden (1967): The famous “Dagen H” switch from left to right reduced cross-border hazards with Norway and Finland and aligned with car imports.
• Iceland (1968): Followed Sweden to harmonize with continental Europe.
• Central and Eastern Europe (interwar and post–World War II): Standardized on right alongside neighbors; many cities and regions made stepwise changes.
• Mainland China (mid-20th century): Consolidated on right nationwide; Hong Kong and Macau remain left, with engineered crossovers at boundaries.
• Nigeria (1972) and Ghana (1974): Moved to right to match surrounding states and simplify trade and traffic.
• Samoa (2009): A rare modern switch the other way—to left—to align with Australia and New Zealand vehicle markets.

These shifts required years of planning, massive public-information campaigns, and redesigns of signage, intersections, and buses—costly undertakings justified by long-term safety and economic gains.

Where the right dominates—and where it doesn’t

The world’s traffic pattern reflects history and trade links more than any inherent safety advantage of one side over the other.

• Scale: Roughly three-quarters of countries—and about 75% of the world’s population—use right-hand traffic.
• Europe: Almost all of continental Europe drives on the right; the UK, Ireland, Malta, and Cyprus drive on the left.
• Americas: Nearly all countries drive on the right, with left-side exceptions mainly in the Caribbean and the Guianas (Guyana and Suriname).
• Asia: Mainland Asia is mostly right-driving; left-driving nations include Japan, Indonesia, Thailand, Malaysia, Singapore, Pakistan, Bangladesh, and several neighbors.
• Africa: Mixed patterns mirror colonial legacies—former British territories often drive on the left; former French, Portuguese, and Spanish ones generally on the right.
• Oceania: Australia and New Zealand are left-driving; Pacific islands align broadly with historic and economic ties.

The result is a patchwork shaped by empire, commerce, and geography rather than a single global rule.

Does one side prove safer?

There is no conclusive global evidence that driving on the right or the left is intrinsically safer if roads, vehicles, and training are designed accordingly. The biggest safety risks arise during a transition and at borders, which is why large-scale switches are now uncommon and meticulously planned when they occur.

Summary

Countries drive on the right largely because French and American practices, wagon-era logistics, and the global spread of left-hand-drive cars set a powerful precedent that regions reinforced for trade and safety. Left-hand systems persist where British and Japanese influence prevailed. International law permits either side; what matters most is consistency with neighbors and vehicle markets, not the side itself.

What country drives on the left?

LHT was introduced by the UK in British India (now India, Pakistan, Myanmar, and Bangladesh), British Malaya and British Borneo (now Malaysia, Brunei and Singapore), as well as British Hong Kong. These countries, except Myanmar, are still LHT, as well as neighbouring countries Bhutan and Nepal.

Why doesn’t the US drive on the left?

Lay agreed with Rose that the Conestoga wagon provided a “major impetus for right-hand driving in the United States”: The wagon was operated either by the postilion driver riding the left-hand near horse-called the wheel horse-or by the driver walking or sitting on a “lazy board” on the left-hand side of the vehicle.

Why do most countries drive on the right?

The subsequent Revolutionary wars and Napoleon’s European conquests led to the spread of driving on the right to Switzerland, Germany, Italy, Poland, Spain, Belgium and the Netherlands. Napoleon ordered his armies to use the right-hand side of the road in order to avoid congestion during military manoeuvres.

Why does Japan drive on the left?

Japan’s left-hand traffic system is the result of a combination of historical traditions, including samurai customs, horse-drawn cart practices, and the influence of British railway engineers during the Meiji era.