<P> Some historians, such as C. Northcote Parkinson, believed that ancient travellers on horseback or on foot generally kept to the left, since most people were right - handed . If two men riding on horseback were to start a fight, each would edge toward the left . In the year 1300, Pope Boniface VIII directed pilgrims to keep left . </P> <P> In the late 1700s, traffic in the United States was RHT based on teamsters' use of large freight wagons pulled by several pairs of horses . The wagons had no driver's seat, so the (typically right - handed) postilion held his whip in his right hand and thus sat on the left rear horse . Seated on the left, the driver preferred that other wagons pass him on the left so that he could be sure to keep clear of the wheels of oncoming wagons . </P> <P> In France, traditionally foot traffic had kept right, while carriage traffic kept left . Following the French Revolution, all traffic kept right . Following the Napoleonic Wars, the French imposed RHT on parts of Europe . During the colonial period, RHT was introduced by the French in New France, French West Africa, the Maghreb, French Indochina, the West Indies, French Guiana and the Réunion, among others . </P> <P> Meanwhile, LHT was introduced by the British in parts of Canada (Atlantic Canada and British Columbia), Australia, New Zealand, the East Africa Protectorate (now Kenya, Tanzania and Uganda), British India, Rhodesia and the Cape Colony (now Zambia, Zimbabwe and South Africa), British Malaya (now Malaysia, Brunei and Singapore), British Guiana, and British Hong Kong . LHT was also introduced by the Portuguese Empire in Portuguese Macau, Colonial Brazil, Portuguese Timor, Portuguese Mozambique, and Portuguese Angola . </P>

When did france change to driving on the right