Why Do Some Countries Drive on the Left and Some on the Right?

Right Hand Drive Vs Left Hand Drive

The following is a great article, excerpted in ExPo, about a recent Earthcircuit.org article, with a title of the same name.  One of the most interesting parts of travelling is that you are forced on a daily basis to deal with the inane arbitrary differences of modern infrastructure.  This goes along with my recent post on international electric plugs. History buffs rejoice.