i don't know if its a law, but as a kid I've always been told to walk on the right side of the road. whether we have adopted this because someone decided that people should have a dedicated side of the road to walk on, or for some other social reason, im here to tell you why its a good idea from a physics standpoint. at least here in america, where the cars drive on the right side as well, physics says that people are safer when they walk on the right. it all has to do with relative velocities. when cars and people are going in the same direction, the velocity of the car relative to the person is less than the velocity of a car relative to a person when people travel in the direction opposite traffic, as when people walk on the left side. what does this mean? if a person traveling on the right is hit by a car, the relative velocity of the car is less than that of a person traveling on the left, so the acceleration of the person on the right would be greater, resulting in more injury.