Why Japan Uses Left-Hand Traffic

Japan keeps to left-hand traffic largely because British engineers set Japan’s first railways to run on the left in 1872, a pattern that influenced road rules and was later written into national law; earlier pedestrian customs also favored keeping left, and the system has remained in place ever since, with the notable postwar exception and 1978 reversion in Okinawa. This article explains the historical origins, legal codification, and practical factors that led Japan to drive on the left and why the system endures today.

Deep Roots: From Edo-Era Customs to Modern Habits

Long before motor vehicles, many streets in the Edo period (1603–1868) saw people habitually pass on the left. While historians debate how uniform or official this was, practical reasons likely encouraged left-side passing: most people were right-handed, samurai wore swords on the left hip, and keeping to the left reduced collisions of scabbards and eased crowd flow on narrow roads. These were conventions rather than a single nationwide statute, but they shaped expectations in busy urban centers such as Edo (Tokyo), Osaka, and Kyoto.

British Railways Cemented the Pattern (1872 Onward)

The decisive nudge came with rail. Japan’s first railway, opened in 1872 between Shimbashi (Tokyo) and Yokohama, was planned and built with British engineering expertise. Like the United Kingdom, trains ran on the left, and that standard spread across the rapidly expanding network. As rail, stations, and signaling normalized left-running, the broader transport ecosystem—from carriage flows near stations to road signage conventions—was drawn in the same direction.

From Custom to Law: National Codification

As Japan modernized its roads in the late 19th and early 20th centuries, keep-left rules appeared in police ordinances and traffic orders across major cities and prefectures. Over time this was unified into national standards. Today, the legal foundation is clear: Japan’s Road Traffic Act (enacted in 1960 and subsequently amended) mandates that vehicles drive on the left nationwide. This codification locked in decades of practice and aligned road operations, driver training, and vehicle manufacturing with left-hand traffic.

Okinawa’s Exception and the “730” Reversion

One region temporarily diverged: under U.S. administration after World War II, Okinawa switched to right-hand traffic (RHT). Following the prefecture’s return to Japan in 1972, authorities planned a return to LHT. On July 30, 1978—known locally as “730”—Okinawa executed a massive, well-orchestrated switchover back to left-hand driving, changing road markings, signs, and bus doors overnight. Since then, all of Japan has been uniformly LHT.

Why Left-Hand Traffic Endured: Practical and Institutional Factors

Beyond history and law, a set of practical reasons reinforced Japan’s commitment to left-hand traffic. The following points outline the main forces that have sustained the system.

• Rail-road alignment: With trains running on the left, matching road norms simplified signage, junction design near stations, and traveler expectations.
• Vehicle ecosystem: Domestic manufacturers build right-hand-drive vehicles optimized for LHT, and supply chains, driver training, and maintenance standards are tailored accordingly.
• Infrastructure lock-in: Intersections, expressway ramps, lane markings, and signal phasing all assume left-side flows; reversing this would be disruptive and costly.
• Safety familiarity: Decades of driver education and public behavior around left-hand norms reduce error risk; wholesale changes can elevate crash rates during transition.
• Regional coherence: Many Asia-Pacific neighbors also use LHT, facilitating vehicle flows and imports across regional markets.

Together, these factors made left-hand traffic not just a historical legacy but a deeply embedded system with high switching costs and clear operational advantages in Japan’s context.

How Japan Fits Globally

Japan is part of a global minority that uses left-hand traffic, a group shaped by British influence and regional histories. The following examples help place Japan within the international picture.

• United Kingdom and Ireland in Europe.
• Australia and New Zealand in Oceania.
• India, Pakistan, Bangladesh, Sri Lanka, Thailand, Malaysia, Singapore, and Indonesia in Asia.
• South Africa and several neighboring countries in southern Africa.
• Parts of the Caribbean and some Pacific islands.

These countries differ widely, but many share historical ties to British engineering or administration, which propagated LHT standards during key phases of transport development.

Key Milestones at a Glance

The following timeline highlights the pivotal moments that explain why Japan drives on the left.

• Edo period (1603–1868): Left-side passing becomes a common urban convention, though not uniformly legislated nationwide.
• 1872: First railway (Shimbashi–Yokohama) opens with British engineering; trains run on the left, setting a national rail standard.
• Early 20th century: Keep-left rules spread via local ordinances and are increasingly standardized.
• 1960: Japan enacts the Road Traffic Act, formally mandating left-hand driving nationwide and modernizing traffic regulation.
• 1945–1972: Under U.S. administration, Okinawa adopts right-hand traffic.
• July 30, 1978 (“730”): Okinawa switches back to LHT, restoring uniformity across Japan.

Viewed together, these milestones show how custom, imported rail standards, and modern law converged to establish and maintain left-hand traffic across Japan.

Summary

Japan’s left-hand traffic is the product of layered influences: Edo-era customs primed the habit, British-built railways in 1872 entrenched left-running in transport culture, and nationwide laws—culminating in the 1960 Road Traffic Act—made it official. With vehicles, infrastructure, and safety systems now optimized for LHT, and after Okinawa’s 1978 “730” reversion, left-hand traffic remains the efficient, unified standard across the country.

Why does Japan have left-hand traffic?

Japan drives on the left due to its history with samurai, who kept their swords on their left hip, necessitating left-side passage to avoid collisions. This tradition was reinforced when British companies helped build Japan’s first railways in the 1870s, adopting British left-hand track practice, a system eventually codified into law for all vehicles by 1924.
 
Historical Roots

• Samurai Culture: Opens in new tabIn feudal Japan, most samurai were right-handed and carried their swords on their left hip. Walking on the left allowed them to pass others without their scabbards clashing, which was a serious provocation. 
• Public Adoption: Opens in new tabThis custom of left-side passage became a norm in society, and people would get out of a samurai’s way to avoid conflict. 

Influence of Railways 

• British Technical Aid: Opens in new tabWhen Japan began modernizing in the late 19th century, British engineers were instrumental in constructing the nation’s first railway system.
• Left-Side Trains: Opens in new tabThese railways adopted the British practice of left-hand traffic for trains and, later, electric trolleys.

Formalization into Law 

• Codification: The tradition of left-side driving, rooted in samurai custom and reinforced by the railway system, was officially codified into national law in 1924.

In summary, Japan’s driving on the left is a direct result of pre-modern samurai customs and the early adoption of British railway practices, which were later formalized into nationwide traffic law.

Why does left-hand traffic exist?

In the past, almost everybody travelled on the left side of the road because that was the most sensible option for feudal, violent societies. Since most people are right-handed, swordsmen preferred to keep to the left in order to have their right arm nearer to an opponent and their scabbard further from him.

Why does Korea drive on the right?

Korea, meaning the unified Korean peninsula at the time of the change, shifted to driving on the right after 1945 because the American and Russian military vehicles that occupied the roads were designed for right-hand traffic, a legacy of U.S. and French influence, which prevailed over the left-hand driving tradition inherited from Japanese colonial rule.
 
Historical context

• Japanese Influence (driving on the left): During its colonial period, Korea was under Japanese rule, and Japan itself drives on the left due to historical British influence and the construction of its first railway system based on the British model. 
• Post-WWII Transition to Right-Hand Traffic: After the end of the Second World War, Korea was divided into two occupation zones: American and Russian. 
  • American and Russian Vehicles: The presence of American-made and Russian-built vehicles, which are designed for driving on the right side of the road, directly led to the implementation of right-hand driving on the Korean peninsula. 
• Cultural and Political Influence: Countries influenced by the United States, France, or Germany generally adopt right-hand driving systems. Korea’s post-colonial alignment with these influences meant a shift away from its prior left-hand traffic system to the right. 

Summary
The change from left-hand to right-hand driving in Korea was a direct consequence of the American and Russian presence after the Japanese colonial era. The prevalent use of American and Russian vehicles, which were designed for right-hand traffic, directly caused the shift and solidified the right-hand rule for driving on the peninsula.

Does America use left-hand traffic?

Yes, most vehicles in the United States are left-hand drive because the U.S. drives on the right side of the road, a practice that became standard in Colonial America. The driver’s position on the left provides better visibility of oncoming traffic and makes it easier to safely pull out from parallel parking. An exception is the U.S. Virgin Islands, where drivers travel on the left, but cars still have their steering wheels on the left, which is a unique situation.
 
Why the U.S. uses left-hand drive cars:

• Right-hand travel: The U.S. adopted right-hand driving early on, with New York instituting the rule for public highways in 1804. 
• Visibility: Having the steering wheel on the left allows drivers to better see oncoming traffic that is coming from the left. 
• Historical factors: The tradition of right-hand driving may stem from large, bulky Conestoga wagons and a resistance to British customs, which favored left-hand traffic. 

Where it’s different:

• U.S. Virgin Islands: Opens in new tabThis U.S. territory drives on the left side of the road, though their vehicles still have the steering wheel on the left. 
• Specialized Vehicles: Opens in new tabA small number of specialized U.S. vehicles, such as mail delivery vehicles, may be built with right-hand drive to improve functionality for the driver. 

Where to see right-hand drive cars: 

• In countries like the United Kingdom, Japan, India, and Australia, which drive on the left side of the road.