Today, about 70% of the world's countries and territories implement right-hand traffic (RHT) while the remaining use left-hand traffic (LHT), accounting for about a sixth of the world's area, 35% of its population and 25% of its roads.

Right-hand traffic (RHT) is the practice of keeping to the right side of the road, in bidirectional traffic. In RHT, vehicles keep right and the cars are left-hand drive (LHD) with the steering wheel on the left-hand side of the car.

Likewise, left-hand traffic (LHT) is the practice of keeping to the left side of the road, in bidirectional traffic. In LHT, vehicles keep left and the cars are right-hand drive (RHD) with the steering wheel on the right-hand side of the car.