True to the topic, here's something random:
A good number of countries switched from left-hand traffic to right-hand traffic at some point. Many countries, especially in the Commonwealth, retain left-hand traffic. However, only two countries in the world ever switched from right-hand to left-hand traffic, and keep it to this day. Any guesses which countries, and why? Here's a hint: One of them could be guessed with some knowledge of world history, the other one with very good knowledge of political geography.