rule of the road: Meaning and Definition of

rule' of the road'

Pronunciation: [key]
— Naut. Naut.
  1. any of the regulations concerning the safe handling of vessels under way with respect to one another, imposed by a government on ships in its own waters or upon its own ships on the high seas.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.