Teamsters in the United States began hauling farm products pulled by several pairs of horses.  These wagons had no driver's seat; instead the driver sat on the left rear horse so that he could keep his right arm free to lash the team.  Since he was sitting on the left,  naturally he wanted others to pass on the left so that he could look down and make sure that he kept clear of passing wagon's wheels.  Thus he kept to the right hand side of the road.   By the 1860s, right hand driving was followed in almost every state with the driver sitting on the right to ensure that their wagon did not run into a roadside ditch.  Automobile designers copied this with the driver placed on the curbside and this remained normal practice till 1915.  However, in 1908 Ford's Model T became the first popular car to feature a left hand position for the driver and by 1915, all the other car makers had followed Ford's lead.

 

Contributed by RGHF member PDG Ian Harley Campbell, D1230 UK 14 May 2008