How Did Driving on the Right Originate in America?
The drivers of early freight wagons started the American custom of driving on the right side of the road. Americans had been following the English custom of driving on the left. The wagon driver, however, walked to the left or rode the lazy board, a sliding board between the left wheels from which he could guide the horses and operate the brake.
For the driver to clearly view the road, the wagon had to be kept to the right. This forced other vehicles to do the same when passing from the opposite direction. Everyone soon adopted the practice.
Early American motor vehicles were right-hand drive, following the practice established by horse-drawn buggies. This changed in the early years of the 20th century: Ford changed to LHD production in 1908 with the Model T, and Cadillac did so in 1916.
Today, US motor vehicles are LHD, except postal mail vehicles. A large number of vehicles used for rural mail delivery are RHD, thus enabling the driver to access roadside mail receptacles without leaving the vehicle.
American drivers nearly always drive on the right and pass on the left, but state traffic laws generally allow for passing on the right if there is sufficient space to the right of the leading vehicle to pass it safely. Since this is not usually the case, right-side passing is rare except on multi-lane roads and divided highways, or when passing other vehicles that are preparing to turn left.
Traffic on the US Virgin Islands drives on the left; thus, the US Virgin Islands is the only American jurisdiction that still has left-hand traffic, because the islands drove on the left when the United States purchased the former Danish West Indies from Denmark in 1917. However, virtually all passenger vehicles are left-hand drive due to imports of US vehicles.
Despite the developments in the US, some parts of Canada continued to drive on the left until shortly after the Second World War. The territory controlled by the French (from Quebec to Louisiana) drove on the right, but the territory occupied by the English (British Columbia, New Brunswick, Nova Scotia, Prince Edward Island and Newfoundland) kept left.
British Columbia and the Atlantic provinces switched to the right in the 1920s in order to conform to the rest of Canada and the USA. Newfoundland drove on the left until 1947, and joined Canada in 1949.