Why Japan Drives on the Left

Japan drives on the left primarily because left-side travel became entrenched before cars—rooted in samurai-era customs and packhorse logistics—then was cemented by British-built railways in the 19th century and later codified by national traffic laws. Aside from a U.S.-administered interlude in Okinawa after World War II, Japan has consistently kept left, with Okinawa returning to left-side driving in 1978.

Historical Roots Before Automobiles

Long before motor vehicles, Japan developed practical reasons to favor the left. During the Edo period (1603–1868), samurai typically passed on the left to keep their sword arm (on the left hip, drawn with the right hand) away from oncoming traffic, reducing accidental clashes. Packhorse caravans and foot traffic also tended to keep left to coordinate movement on narrow roads and bridges, a custom reinforced by local regulations in major cities.

Railways Set the Pattern

Japan’s first modern railway, the Shimbashi–Yokohama line opened in 1872, was engineered with British assistance. Because Britain runs trains on the left, Japanese railways adopted left-hand running from the outset. As rail expanded nationwide, stations, signals, and habits aligned with left-side movement, helping normalize “keep left” as the default for mass transport and shaping expectations for road use as automobiles arrived.

From Custom to Law: Codifying Keep-Left

As cars proliferated in the early 20th century, police ordinances and national regulations standardized left-side driving on roads to match long-standing practice and the railway convention. Postwar legal frameworks reaffirmed this: Japan’s modern Road Traffic Act (1960) codified keep-left nationwide, aligning vehicle standards, signage, and driver education around left-side travel.

The Okinawa Exception and the “730” Switch

Okinawa, under U.S. administration after World War II, was switched to right-side driving to match American practice. After reversion to Japanese sovereignty in 1972, the region planned a return to national norms. On July 30, 1978—nicknamed “730”—Okinawa executed a massive, one-day change back to left-side driving, involving retiming signals, repainting road markings, swapping bus doors, and retraining drivers, restoring uniformity across Japan.

A Brief Timeline of How Left-Side Driving Took Hold

The following timeline highlights key moments that explain how and why left-side driving became Japan’s standard and remained resilient over time.

1. Edo period (1603–1868): Samurai etiquette and packhorse logistics favor passing on the left.
2. 1872: First railway opens (Shimbashi–Yokohama), built to British practice; trains run on the left.
3. Early 20th century: Police and national regulations standardize left-side road traffic as cars spread.
4. 1945–1972: Okinawa, under U.S. administration, operates right-side driving.
5. 1960: Japan’s Road Traffic Act reaffirms nationwide keep-left rules and standards.
6. July 30, 1978: “730” operation returns Okinawa to left-side driving, unifying the country’s practice.

Taken together, these milestones show how custom, infrastructure, and law converged to make left-side driving both practical and durable in Japan.

Why Japan Didn’t Switch to the Right

Multiple factors discouraged any later switch to right-side driving. By the mid-20th century, the entire system—roads, vehicle fleets, training, signage, and public transport—was optimized for the left. Changing sides would be costly, disruptive, and offer little benefit in an island nation with limited land borders. The brief Okinawa exception underscored the complexity and expense of such a shift, reinforcing the status quo.

What Left-Side Driving Means in Daily Life

Left-side driving affects more than just which lane cars use; it shapes vehicle design, road engineering, and even pedestrian habits in cities.

• Vehicles: Most cars are right-hand-drive, with controls and visibility optimized for left-side traffic.
• Road design: Interchanges, bus doors, platform layouts, and signage conform to left-hand flow.
• Pedestrians: Walking and queuing often mirror left-side norms, though practices vary by region and city.
• Logistics: Deliveries, curbside stops, and parking standards are built around left-lane operations.

These everyday details reinforce the left-side system, making it intuitive for residents and visitors who adopt local conventions.

International Context

Japan is among a minority of countries that drive on the left—alongside the UK, Australia, New Zealand, India, and several Southeast African and Southeast Asian nations—reflecting historical ties and engineering lineage rather than any inherent safety difference between left and right.

Summary

Japan drives on the left because historical custom aligned with British-influenced railways and was ultimately embedded in law. Early Edo-era practices primed the country for left-side conventions; 19th-century rail cemented them; 20th-century regulations made them uniform. Apart from Okinawa’s postwar right-side interlude—reversed in 1978—the nation’s left-side driving has remained consistent, efficient, and deeply integrated into everyday life.

Why does the UK drive on the left?

There is an historical reason for this; it’s all to do with keeping your sword hand free! In the Middle Ages you never knew who you were going to meet when travelling on horseback. Most people are right-handed, so if a stranger passed by on the right of you, your right hand would be free to use your sword if required.

Why do Japanese drive on the left side?

Samurai ruled the Japanese society during Edo period (1603-1867). And left-side passage suited their peacetime lifestyle. So left-side passage could be considerably prevalent in Japan back then. But this does not necessarily follow that non-Samurai people–farmers, craftsmen, merchants–strictly kept left-hand traffic.

Did Canada ever drive on the left side of the road?

Driving in the left lane was the norm on the east and west coasts of Canada, until cross-country jaunts by automobile became more common and the need for standard cross-border traffic rules became more urgent. Central Canada and the prairie provinces had always followed the American practice of driving on the right.

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.