In common with most of both the North and South America, and much of the world, here in Panama, we drive on the right hand side of the road. Though much of the Caribbean drives on the left, in the continental mainland, only Guyana and Suriname do so. However, it was not always so, it was as recently as 1943 that Panama switched from driving on the left to driving on the right.
Panama City’s tram systems, which ran during the first half of the twentieth century were all designed to run on the left (with the passenger doors on the left hand side to allow passengers to alight and dismount to the pavement), and it is possible that the 1943 change contributed to their being withdrawn from service in 1941 (though competition from other sources had already made the trams uneconomic).
There is contradictory evidence as to which side of the road the ancient Romans used, but at an old Roman quarry in England, the ruts in the road are far deeper on the left (showing that the loaded carts were leaving the quarry on that side. For most of recorded history, it was usual to drive your cart, ride your horse or even just to walk on the left hand side of the road. For most people, this left the right hand free to greet anyone passing them on the right, or, if necessary to defend themselves against any aggression.
Driving on the right hand side of the road seems to have arisen in the USA, where teamsters with large carts and teams of draft animals wanted to ride the rear animal on the left, so that the whip (usually held in the right hand) could reach all the animals. In order to check that they would clear wagons coming the other way, they wanted to drive on the right, putting their mount closest to the center of the road.
