Did you know that cars in Panama and the Canal Zone used to drive on the left-hand side of the road?

At 4:57am on the morning of April 15, 1943 sirens and fire whistles across Panama blew for three whole minutes. Traffic came to a complete stop. At 5:00am vehicles slowly made their way to the other side of the road, leaving left-hand driving behind, and carried on with the day on the right side of the road. The transition went off without a hitch – the only issues involved two caramettas whose horses didn’t understand why they had to change their well-worn routine.

Speed limits were reduced for one month to mitigate the damage from any traffic mishaps.

The significant change to the rules of the road had been under discussion for over 20 years. With staunch supporters on both the left-hand and right-hand driving side of the debate, little progress towards consensus was made. However, with the construction of the Pan American Highway in the 1930s and the influx of workers and soldiers from the U.S. and other countries who were accustomed to right-hand driving, the decision was finally made to transition.

"It is important that the automobiles of Panama and the Canal Zone be transferred to the right side of the road before the Pan American Highway is opened if vehicular confusion, approximating the linguistic tangle encountered by the builders of the Tower of Babel, was to be avoided... Should this strip on the through route from Alaska to Patagonia retain the left side drive, the interesting result would be signs notifying motorists to transfer to the opposite side of the road when crossing the Panamanian border."
Panama American, 1931 (quote taken from the Panama Canal Review, Fall 1973)

Theories abound regarding the origin of left and right hand driving – usually tied to how people in the region controlled horse drawn carriages or drove animals for agriculture. Some archaeologists even suggest left-hand driving came from the ancient Romans, possibly for safety and the ability to wield a weapon with the commonly dominant right hand.

Use the left and right arrows to flip through the slideshow of left-hand driving in Panama and the Canal Zone.

And here is a classic street shot of Ave. Central in Panama City after the switch to right-hand driving.

Remember: if you are ever trying to date an old family photo in Panama or the Canal Zone, look at the cars…if they are driving on the left-hand side of the road you know the photo was taken before April 1943.