Why Japan Drives on the Left

Japan drives on the left primarily because historic customs were reinforced by British-built railways in the 1870s and later codified in nationwide traffic laws; the system has remained consistent ever since, with the notable exception of Okinawa, which switched back to left-hand traffic in 1978 to align with the rest of the country. In practice, this means traffic keeps left and most vehicles are right-hand-drive (steering wheel on the right), a configuration considered safer for overtaking and curbside visibility under left-hand traffic rules.

Historical Roots: Customs Before Cars

Long before motor vehicles, patterns of movement in the Edo period (1603–1868) favored keeping left on busy highways. Samurai wore swords on the left, and passing on the left reduced scabbard clashes; packhorses and palanquins also benefited from a consistent side to reduce collisions. While practices varied by place, historical ordinances and guides from major routes such as the Tōkaidō indicate a left-side preference in crowded corridors.

British Influence via the Railways

The strongest early standard-setter came with rail. Japan’s first railway, opened in 1872 between Shimbashi (Tokyo) and Yokohama, was engineered with substantial British involvement. It adopted British-style left-hand running, and as the rail network expanded nationwide, left-side operation became the norm for trains. This embedded leftward traffic habits into urban design and public expectations decades before private car ownership became widespread.

From Practice to Policy: How It Became Law

The sequence below outlines how Japan’s keep-left practice moved from custom to national law and was later reaffirmed in modern statutes.

1. 1870s–1890s: Left-hand running is established on railways built with British engineering practices.
2. Late 19th century: Major cities, notably Tokyo, issue police ordinances instructing carts and carriages to keep left to reduce congestion and accidents.
3. 1920s: National regulations standardize left-hand road traffic, aligning road rules with entrenched railway practice and urban ordinances.
4. Post-1945: Japan maintains left-hand traffic; the current Road Traffic Act (1960, as amended) continues to govern left-side operation.
5. 1978: Okinawa, which had driven on the right under U.S. administration after WWII, switches back to the left on “730 Day” (July 30) to match the rest of Japan.

Taken together, these steps show a steady convergence: local practice informed early rules, national law locked them in, and postwar legislation and regional alignment kept the system uniform.

Why Cars in Japan Are Right-Hand-Drive

Because traffic keeps left, drivers sit on the right. This positioning improves forward visibility for overtaking and gives the driver a better view of the centerline and oncoming traffic. It also simplifies curbside maneuvers like bus stop alignment and delivery drop-offs. While some left-hand-drive imports exist, right-hand-drive vehicles dominate the Japanese market.

Okinawa’s Unique Postwar Detour

Okinawa is the major exception that proves the rule. Under U.S. administration after World War II, it adopted right-hand traffic. After reversion to Japan, the prefecture executed a complex, well-publicized switch back to left-hand driving on July 30, 1978—nicknamed “730”—involving mass retiming of signals, repainting of lanes, public education, and fleet adjustments. Since then, Japan has had a uniformly left-hand system.

Key Factors Behind Japan’s Left-Hand Traffic

The following points summarize why left-hand traffic took hold and persisted in Japan.

• Edo-period travel norms that favored keeping left on crowded routes.
• British engineering influence, which set left-hand running as the standard for railways from 1872 onward.
• Early urban ordinances that formalized keep-left practices for carts and carriages.
• National traffic regulations in the early 20th century that codified left-hand road traffic.
• Postwar legal continuity and the 1978 Okinawa switch that unified the rule nationwide.

These factors reinforced one another over time: culture shaped early behavior, infrastructure set expectations, and law cemented the norm.

Global Context

Where Japan Fits Internationally

Japan is part of a minority of countries that drive on the left, a group that includes the United Kingdom, Australia, New Zealand, India, Thailand, and several nations in Southern Africa and Southeast Asia. Like Japan, many of these countries inherited left-hand traffic through British influence, whether via direct rule, engineering standards, or trade and technology transfer.

Summary

Japan drives on the left because historical customs were reinforced by British-built railways and later standardized by national law. The system has been consistently maintained, with Okinawa’s 1978 change aligning the last outlier. In this framework, right-hand-drive vehicles are the practical and legal fit for Japanese roads, reflecting a coherent traffic system with deep historical roots.

Why do Japanese drive on the left side?

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.

Why do British drive on the left?

British drive on the left due to historical reasons, particularly the prevalence of right-handed people and the need to keep their sword hand free for defense when traveling on horseback in the Middle Ages. This custom continued with smaller carriages, where drivers sat to the right to keep their whip hand free. The practice was later formalized into law, with the Highway Act of 1835 mandating left-hand driving throughout the UK and solidifying it as a permanent habit.
 
Historical Origins 

• Medieval Times: In the days of knights and horseback riders, staying to the left allowed right-handed individuals to keep their sword arm free to defend themselves against oncoming strangers.
• Roman Influence: Evidence suggests that Roman soldiers also marched on the left, and some archaeological findings point to Romans driving carts and wagons on the left.
• Early Regulations: Pope Boniface VIII officially sanctioned keeping to the left for pilgrims visiting Rome in the year 1300, which influenced the practice in parts of Europe.

Transition to Modern Driving 

• Carriage Drivers: Opens in new tabWhen larger wagons and carriages with driver’s seats became common in the 18th century, the practice of sitting on the right to control the horses and keep the whip hand free further solidified driving on the left.
• Formalization into Law: Opens in new tabThe practice was legally enforced in Britain with the Highway Act of 1835, making left-hand driving mandatory across the country.

Why it Didn’t Change

• Cost and Habits: Changing traffic laws and associated infrastructure is extremely expensive and difficult, especially because habits are hard to break. 
• Continental Influence: The spread of right-hand driving in mainland Europe was largely due to Napoleonic conquests and French influence. Britain, resisting these influences, maintained its left-hand system. 
• Colonial Legacy: Britain’s imperial reach also spread left-hand driving to many of its former colonies. 

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.

Why doesn’t the US drive on the left?

The United States drives on the right because right-hand travel was the norm in Colonial America due to the use of large wagons and practical reasons like ditch avoidance. This custom was codified into law, with New York making it mandatory for public highways in 1804, and it predates the American Revolution, not being an act of rebellion against Britain. 
Early American Practices

• Wagon Drivers: Opens in new tabIn the 18th century, large, heavy freight wagons became popular in the U.S. Drivers often sat on the left rear horse to better manage the team with their right hand and used their right arm to whip the horses, requiring them to keep to the right to avoid ditches and manage the whip more effectively. 
• Right-Handedness: Opens in new tabAs most people are right-handed, keeping to the right also allowed pedestrians and horseback riders to keep their dominant sword arm free for defense against potential threats on the road. 

Legal Standardization 

• Pennsylvania: Opens in new tabThe state of Pennsylvania was an early adopter of right-hand travel, legislating it for its turnpikes in 1792.
• New York: Opens in new tabNew York was the first state to prescribe right-hand travel on all public highways in 1804, establishing a standard that other states soon followed.

Distinction from British and Ancient Traditions

• Colonial Opposition: Right-hand travel in America was not an opposition to British rule but rather a separate path of development. Britain’s left-hand driving law was established in 1773, while right-hand travel had already become the norm in the American colonies. 
• Ancient Origins: While ancient Romans drove on the left, often to keep their sword arm free, early American practices diverged from this due to different transportation methods and societal needs, such as the need to manage large, four-horse teams with a driver seated on the left side of the wagon.