The saying One for the Road originates from the 12th Century. At one end of London's Oxford Street lies Marble Arch. From the 12th Century up until 1783, the Tyburn Gallows stood there, being a place where petty thieves, political prisoners and notorious criminals were hanged. One the way to the hanging, they were lead down the road which is now Oxford Street, but before they left they were allowed one last drink, which is where the saying comes from. In fact, Oxford Street's only pub, The Tottenham, is down the other end of the street, at the Tottenham Court Road end. Once the criminal had drunk their last drink, they were lead towards the gallows on a wagon, which is where the saying on the wagon comes from - i.e. they weren't allowed to drink any more.