Roman roads

Which side of the road did the Romans march on?

I understand that the only reference to this subject is a picture of two riders travelling in opposite directions along a road and they are passing right shoulder to right shoulder. But this does not mean that it was the norm.

There must be more proof than this.

A quote from this page:

Arjuna34

Warning; WAG coming up;

this could be something to do with the sword/handshake thing being doen with the right hand; this hand is nearest to anybody that you pass travelling in the opposite direction.

Mangetout hit it right on the head. We know that Cecil doesn’t make guesses.