Why Don’t We All Drive on the Same Side? (Encore)

Roman Influence

The tradition of driving on the left in Britain can be traced back to ancient Roman practices. Gary Arndt explains that Romans rode on the left to keep their right hand free for defense, a custom that persisted in Britain due to its Roman heritage 1. This practice was codified in laws from the 17th and 18th centuries, particularly for crossing bridges in London. However, these laws suggest that driving on the left wasn't universally practiced in England at the time.

Most of the theories are based on the fact that most people are right handed. 90% of the population is right handed, and back in the day, left handers were often forced to do things right handed.

--- Gary Arndt

The influence of Rome on continental Europe was more significant, yet the driving customs varied widely until the late 19th century when France standardized driving on the right 1.

   

Napoleonic Changes

The shift in driving sides during the Napoleonic era marked a significant change in Europe. Gary Arndt notes that Napoleon, who was left-handed, is often credited with changing France's driving side from left to right, although evidence suggests there was no standard rule at the time 1. By the late 19th century, as automobiles emerged, France led the way in adopting right-side driving, influencing neighboring countries to follow suit.

France appears to have been the first to have adopted traveling on the right, and then every other country standardized it over time.

--- Gary Arndt

This alignment with France's standard can be likened to a magnetic pull, with other European nations adjusting their driving sides to match 1.

   

American Evolution

In the Americas, the evolution of driving standards diverged from European norms. Early settlers in the United States and Canada, despite their British colonial roots, adopted right-side driving from the outset 2. Gary Arndt attributes this to practical reasons, such as the use of muskets, which were easier to handle from the right side.

If the United States and Canada are former british colonies, why do they drive on the right instead of the left? All evidence points to the fact that early settlers in the Americas used the right side from the beginning.

--- Gary Arndt

Resistance to European customs further solidified this practice, with the first legal mandate for right-side driving appearing in Pennsylvania in 1792. By the Civil War, right-side driving was the norm across the United States 2.