Why Americans Drive on the Right

Americans drive on the right largely because of 18th-century wagon practices that favored right-side travel, early state rules—such as Pennsylvania’s 1792 turnpike regulation and New York’s 1804 statute—requiring “keep right,” and the 20th-century standardization of automobiles with left-hand steering (popularized by the Model T), which reinforced right-hand traffic nationwide; a notable exception is the U.S. Virgin Islands, where drivers keep left.

From Wagons to Road Rules: How the Pattern Began

In the late 1700s, freight wagons like the Conestoga, common across the American colonies and early republic, were typically driven by teamsters who rode the left rear horse or walked on the left side to keep their right arm free for the whip. Staying to the right of the road made it easier to judge clearance with oncoming carts and reduce collisions. This practical custom grew into a widespread convention on busy trade routes long before cars existed.

The Law Catches Up: Early “Keep Right” Statutes

As roads and commerce expanded, states began formalizing road conduct. One of the earliest and most-cited directives came with Pennsylvania’s 1792 rules for the Philadelphia–Lancaster Turnpike, which told travelers to keep to the right. New York followed with an 1804 law requiring vehicles to keep to the right when meeting others. By the mid- to late 19th century, most states had comparable provisions, turning what began as a practical custom into enforceable law.

How the Automobile Cemented Right-Hand Traffic

Early automobiles borrowed carriage layouts, but placement of the steering wheel became crucial to visibility and safety. Henry Ford’s Model T (1908) standardized left-hand steering, which makes the most sense in countries that drive on the right: it places the driver closer to the centerline for better sightlines when passing and aligning in traffic. As mass-produced cars proliferated, state motor-vehicle codes, driver testing, and uniform signage reinforced right-hand traffic nationwide, locking in the rule.

Why the U.S. Didn’t Follow Britain’s Left-Side Tradition

Britain historically kept left—a practice with medieval roots that favored right-handed swordsmen meeting oncoming travelers. The American pattern diverged due to different transport needs (large freight wagons and team driving), early state-by-state regulation, and the absence of a centralized imperial standard after independence. On the European continent, Napoleon-era reforms pushed many countries to the right; in the United States, the combination of practical wagoncraft and early statutes did the same.

Standardization—and the Rare Exception

By the 1920s, right-hand traffic was embedded in state law across the United States. National frameworks like the Uniform Vehicle Code (developed in the late 1920s and refined in the 1930s) and the first Manual on Uniform Traffic Control Devices (1935) further unified rules, signage, and lane markings. Neighboring Canada and Mexico also drive on the right, supporting cross-border consistency. One notable outlier under the U.S. flag is the U.S. Virgin Islands, where traffic keeps left due to longstanding local tradition.

Key Milestones in America’s Right-Side Driving

The following timeline highlights pivotal moments that explain how right-side driving took hold and became uniform across the United States.

• 1792: Pennsylvania’s Philadelphia–Lancaster Turnpike publishes “keep right” rules for travelers.
• 1804: New York enacts a law directing vehicles meeting each other to keep to the right.
• Late 1800s: Most states adopt keep-right statutes, reflecting common road practice.
• 1908: Ford’s Model T popularizes left-hand steering, complementing right-hand traffic.
• 1920s–1930s: States codify right-hand driving in motor-vehicle laws; national model codes and uniform signage standards follow (e.g., 1935 MUTCD).

Taken together, these steps show a progression from custom to law to standardization, with vehicle design and mass adoption playing decisive roles.

The Main Forces Behind the Rule

These factors best explain why the U.S. ended up on the right and stayed there.

• Teamster practice: Wagon-driving habits favored right-side travel for better control and visibility.
• Early legislation: Turnpike regulations and state laws locked customs into legal requirements.
• Automotive design: Left-hand steering improved safety in right-hand traffic and became industry standard.
• Interstate consistency: Uniform vehicle codes and signage made one rule essential for a national network.
• Regional alignment: Neighbors (Canada, Mexico) driving on the right reinforced the choice.

Each factor reinforced the others, creating network effects that made right-side driving the obvious, enduring norm in the United States.

Summary

Americans drive on the right because 18th-century wagon practices pushed travelers to that side, early state rules codified the habit, and the automobile era—especially left-hand steering standardized by the Model T—made it safer and more practical. Subsequent uniform laws and signage cemented the rule nationwide, with the U.S. Virgin Islands standing as a notable left-driving exception.

Why did the US decide to drive on the right?

America drives on the right due to colonial-era transportation practices, particularly the use of Conestoga wagons where drivers sat on the left horse to control their whip-wielding, right-handed lashing of the team, naturally preferring traffic pass on the left. This habit, along with a desire to separate from British left-hand traffic customs after the American Revolution, led to right-hand travel becoming the norm, later standardized in states like New York by 1804 and eventually by Henry Ford’s left-side steering wheel placement on the popular Model T.
 
Colonial Practices and Wagon Use

• Conestoga Wagons: Opens in new tabDrivers on large freight wagons, particularly the Conestoga, would sit on the left rear horse. 
• Right-Handed Control: Opens in new tabThis position kept the driver’s right arm free to use their whip to control the team of animals, leading to a natural inclination to keep to the right side of the road. 
• Clear Passing: Opens in new tabKeeping to the right allowed the driver to see the oncoming wagon’s wheels and keep clear of them, facilitating safe passing. 

Cultural Factors

• Rejection of British Custom: The widespread adoption of right-hand travel was partly driven by a desire to establish a distinct American identity, separate from British customs. 
• The Revolution’s Influence: The American Revolution cemented this divergence from Britain, with right-hand travel evolving from a colonial habit to a symbol of national independence. 

Standardization

• Early Laws: Opens in new tabThe Philadelphia and Lancaster Turnpike Road, established in 1795, was the first to mandate right-hand travel. 
• State Legislation: Opens in new tabNew York formalized right-hand travel on all highways in 1804, and by the Civil War, this practice was followed in every state. 
• Henry Ford’s Role: Opens in new tabThe mass production of the left-hand-drive Ford Model T in 1908 further solidified right-hand driving as the standard in the United States, as it became easier for drivers to see and overtake other vehicles. 

Why do Japanese drive on left?

Japan drives on the left due to its history with samurai, who wore swords on their left hip and kept to the left to avoid clashes, a tradition that was later codified into law by the 1870s when the British helped build Japan’s railway system. The British railway’s left-hand precedent was followed for all subsequent railways, trams, and eventually cars, with left-side driving becoming official law in 1924. 
Historical Origins (Samurai Era)

• Samurai and Swords: During the Edo period (1603-1867), samurai wore their swords on their left side, allowing them to draw with their dominant right hand. 
• Avoiding Clashes: To avoid their swords clanking against those of oncoming warriors, people would keep to the left side of the road. 

Transition to Modern Infrastructure

• British Influence: After the Meiji Restoration in 1868, Japan opened up to Western influence and sought help for its modernization. 
• First Railways: In the 1870s, Britain provided technical assistance to build Japan’s first railway system, which was built with a left-hand running precedent. 
• Following the Pattern: This left-side precedent was followed for all subsequent railways and electric tram cars. 

Codification into Law

• Early Orders: The Tokyo police issued an order requiring pedestrians to keep to the left in 1902. 
• Official Law: Left-side driving was officially mandated as law across the nation in 1924. 

Why does the UK drive on the left and the US on the right?

England (and the UK) drives on the left due to a long-standing tradition rooted in the need for right-handed riders and drivers to keep their sword or whip hands free for defense and control, which also made it safer to mount horses from the left. The United States adopted driving on the right because its dominant 18th-century transport involved large, heavy wagons and teams of horses, where the driver would sit on the left horse to control the team and avoid collisions, leading to a tradition of right-hand driving that predated Britain’s formal left-hand law.
 
Driving on the Left (England/UK)

• Pre-Automotive Era: Historically, most people are right-handed. For riders and knights, keeping to the left side of the road allowed their right hand, their dominant and sword hand, to be free to defend against potential attackers. 
• Mounting/Dismounting: It was safer to mount and dismount a horse from the left side of the road, which was the left-hand traffic side, rather than the middle of the road. 
• Official Adoption: Britain formalized this practice, making left-hand traffic the law in the 18th century, which was later reinforced by the Highway Act of 1835. 

Driving on the Right (United States)

• Post-Colonial Transition: After gaining independence, the US had a growing opposition to Old World customs and the British system of left-hand traffic. 
• Wagon and Horse Teams: The dominant form of long-distance transport in the US involved large, multi-horse wagons. Drivers would sit on the left-hand horse, often the rearmost of a team, to keep their right whip hand free to control the animals. 
• Safety and Practicality: Driving on the right allowed drivers to better judge the clearance between passing wagons, as they were seated to the left of the team, near the center of the road. 
• Dominant Practice: This practical shift in the US, driven by large freight wagons, established a tradition of right-hand driving that was distinct from Britain’s. 

Is America the only country that drives on the right side?

RHT is used in 165 countries and territories, mainly in the Americas, Continental Europe, most of Africa and mainland Asia (except South Asia and Thailand), while 75 countries use LHT, which account for about a sixth of the world’s land area, a quarter of its roads, and about a third of its population.