"Left and Right" by Charles Hice is a poem about how Americans drive on the right side of the road and the English drive on the left side of the road. Today, 65 percent of the world's population lives in a nation where driving must be done on the right side of the road.
Some archaeological evidence suggests that ancient Romans drove their carts and other wheeled vehicles on the left side of the road. Historians believe that the historical preference for driving and riding on the left side of the road was because it would allow those riding horseback to shake hands or attack anyone coming from the opposite direction, should the need arise, with their right hand.
In Europe, the concept of driving on the right side of the road is associated with Napoleon, who ordered the change from driving on the left, although there is no consensus as to why Napoleon made this decision.
Today, many countries ban the use of cars where the driver's seat is on the wrong side, although the European Union member states allow registration of cars with a driver's seat on the left or the right. Some countries have rules allowing for the registration of vintage cars with a driver's seat on the incorrect side, even though most cars are required to have the appropriate-side driver's seat.