Why some countries drive on the right side of the road, rather than the left...
I don\'t know if this is definitely correct, but it\'s what my father told me when I was very young.
Driving on the left side of the road, as stated above, was because most people are right handed, and that was the sword-arm, and easier to swing on that side.
When wagons had guards, the driver would sit on the left, and the armed guard on the right. In older times, it was a sword -- still freer to swing. As time advanced, in what we call the \'wild west\', the position was held by a man with a shotgun. As with the right-handed aspect of cavalry riders, the shotgun rested into the right shoulder. In close quarters, the gunman might not have enough freedom of movement if he was pressed up to the driver, and recoil would jostle the driver and give the horses mixed signals.
This is also, from what I was told, why getting the front passenger seat is still called \'shotgun\'.
If anyone knows better/correctly, by all means, educate me.