If you travel to Britain, you'll have to be very careful when you're about to cross the street, because the British drive on the left. But they're not the only ones, as you can see in the map above, other countries drive on the same side: Australia, New Zealand, Indonesia, India, South Africa, Japan, Kenia, among others.
But it's not due to an impulse, it has some historical reasons. Historically, most traffic drove on the left side in most of the civilised world, thanks mostly to the Roman Empire. Archaeologists found that deeper marks or grooves on the roads are seen on their left side.
Bt medieval times, driving on the left is related to knights. Since most people were right-handed, knights held their swords in their right hands and their lances under the right arms.So, on the road, knights walked on the left to make sure that their sword was between them and a stranger, while passing on the right when on horseback. In the 18th century, driving on the left became law to drive on the London Bridge. The General Highways Act of 1773 recommended to drive on the left in the whole of the UK and it 1835 it became compulsory by the Highway Act.
[Based on article from Anglotopia]
Video "LEFT vs RIGHT DRIVING":
We also include a chart with phrasal verbs related with DRIVING.