Motorists need to be made aware of a cyclists presence on the road at night. Anything else is secondary. Having established that a cyclist is on the road in relatively close proximity means that the motorist is prepared to yield to that cyclist whatever he or she does AND also presupposes that whatever the cyclist does will fall in accordance with established protocols. A cyclists does not need to signal a left merge if there isn't anyone closer than 200' following. If there is close following traffic, especially at night, a left merge is one maneuver I personally would avoid, even if it meant missing the turn. Just because your signal is visible doesn't mean that a following car will take a cyclist seriously. At night I use common sense and make maneuvers in such a way that motorists are able to easily infer my intentions. Hand signals become an optional courtesy. FWIW.