Driving Left. Driving Right

Driving ... Left or Right

 If you’ve ever been in a car, you’ve noticed there’s a certain widely practiced custom. Everybody sends their car down one preferred side of the road — left or right — depending on what country they happen to be in. Drivers are pretty consistent about this, and thus everybody’s somewhat less likely to ram into another car nose-to-nose.
 Sticking to your side of the road . . . it’s not just a good idea. It’s the law.

A more complicated view of traffic

 About 65% of the world keeps to the left — this is the US and Canada, and about all of South and Central America, also Europe, and China.
The other 35% of humanity drive to the left. This is significantly the United Kingdom, Ireland, India, and Australia.
 In one of those weird coincidence-type things, folks who live on islands are mostly left handers.  Go figure
 Are there are ancient usages involved?

See the rest at Word Wenches here.
And there's a giveaway book.

one of those Roman streets