Hi, I'm Craig, and where I'm going I don't need roads, and this is Mental Floss video. Today I'm gonna answer, a ming, ming, 257's Big Question.

How did it end up that some countries' citizens drive on the left side of the road and others drive the right? Let's get started!

Currently, driving on the right side of the road is customary in about 75% of countries, but historically, the left side was preferred.

Experts believe that when roads existed primarily for horses, people rode on the left side. This is probably because people who are right handed tented to mount horses from the horse's left side, and they would wanna do that on the curb side, rather than the middle of the the road.

The ancient Egyptians, Greeks, and Romans probably did this when it wasn't uncommon for travellers to have swords. Since most people use their right hands to wield their swords, being on the left side of the road was preferable. They'd be less vulnerable to attacks from people on the other side of the street. And be easy to get all stabby on them. And retaliation.

In the 1300 CE, Pope Boniface VIII stated that people visiting Rome should ride on the left side.

Jumping forward a few centuries, coaches and carriages eventually took over. At this point, legislation had to be made about the rule of the road.

Have you seen Back To The Future, this is, this is a time travelling car.

The first law of this kind was passed in 1756, requiring that drivers on the London Bridge keep to the left. The British Government went on to write the General Highways Act, in 1773. And the Highway Act of 1835. Both mandating that drivers to stay on the left side of the road.

Other countries made legislation just based on what was already common there at the time.

By the 1700 people were building vehicles for farming, which were pulled by horses. So, the driver would whip the horses with their right hand, while they sat on the left side.

And that really jump started the left side driver seat trend, with people driving on the right side of the road. Also, if you see me with my window down, I'm usually whipping the car as I go.

Then, when steering wheels were introduced in the US they were actually on the right side of the car, but, by that time, Americans already preferred to drive on the right side so, Henry Ford made the switch, and put the drivers side on the left. Drivers side left, car on the right.

That way passengers were on the right, so they could get out curb side.
By around 1915 this was a standard for cars in the US.

Those American cars influenced other countries to adopt right-side driving. Throughout the 20th century, Canada, Italy, Spain, Scandinavia, and many African countries switched to the right.

Other countries stuck with driving on the left side, and that's for many reasons. But, basically, it would be really annoying to switch. Roads are already built and people prefer to drive the way that they drive.

Thanks for watching Mental Floss video, which is made with the help of all of these, oh I'm sorry, I thought we were in England, all of these nice people. If you have a Big Question of your own that you'd like answered leave it below in the comments. I'll see you next time.