Currently reading: Chaos, hand signals and the 'code': Driving in 1950s London

Policemen ran junctions with hand gestures and road markings weren't yet painted

"Londoners drive abreast, packed nose to tail and side to side, and they have gradually evolved a complicated code of their own, as different from the Highway Code as contract bridge conventions are from the simple rules of auction.

"The selection of traffic lane, the right of way, all seems to be governed by bids, leads and responses. It is only by this queer but on the whole practical code that London traffic avoids bogging down completely in one solid mass."