Most of the world drives on the right side of the road, but a minority of countries drive on the left. How do countries decide which side they’ll drive on?
The answer varies from country to country, but in most cases, the side a country drives on comes down to history and economics. In feudal Europe, people would travel on the left side of the road because most people were right-handed and wanted the arm that they used for their sword (or other weapon) between them and anyone who approached. As a result, traveling on the left became customary.