Most of the world used to drive cars and carriages on the left side of the road -- including the United States until the early 19th century. About 35 percent of the world’s population still drives on the left side, mostly in countries that were once part of the British Empire. So what happens when you’re driving on the left in Macau, for example, and you’re headed for mainland China, which drives on the right? Thanks to bridge designer Eng Nuno Costa, the transition is a breeze. His elaborate concept for the Lotus Bridge, built in 1999, features three lanes in each direction, with dual bridges that loop around each other to safely move drivers from one side of the road to the other.
Going from left to right:
- The practice of traveling on the left side of the road may have started in feudal societies. Travelers on horseback stayed left so that their right hand was free to wield a sword -- in case they encountered an enemy.
- Before the French Revolution of 1789, the aristocracy always traveled on the left, forcing peasants to the right. During the revolution, aristocrats found it safer to join the peasants on the right; an official-keep right rule was introduced in 1794.
- On September 3, 1967, Sweden switched from driving on the left to driving on the right in a major logistical undertaking known as Dagen H.