One common practice which is not equal is, if two cars arrive at the same intersection at right angles, then the car on the right has the right of way. This is the common practice, and we do it because it is common practice, and it is common practice because we do it.

We do it that way because the delay the car on the left will experience if the car on the right goes first is shorter than the delay the car on the right would experience if the car on the left went first.

This rule is reversed in left-hand-of-the-road driving regions, because of the reversal of the asymmetry.