So I'm on my phone right now and can't link to the picture but on the Wikipedia article for Pegasus Bridge it shows traffic driving on the left after capture by the British, however surely it would have been in the allied interest to have all traffic on the continent on the right? Sorry if I'm speculating but could anyone shed any light on this?
Practice varied dependent upon the formation. 21st army group's (Anglo-Canadian and polish forces) area of operations had left hand drive, the American sector was right hand. This was due to an inability to agree on which side was the correct side, and was responsible for a significant amount of rage and confusion at all levels during the war.
They drove on the right, as did the French.
Of course, when a small area was under the total control of the British, practices may have varied—and a convoy of right-hand-drive vehicles proceeding across a bridge might find it easier to judge clearances if they drove on the left.