Traffic Light Detection
A side benefit could allow traffic lights to detect cyclists better. Locally 95% of traffic lights have vehicle detectors installed, but are aimed so poorly they don't pick up cyclists. In a few spots I've discovered I have to cross the yellow line to trigger a green light. This could also enable cross traffic / overtaking warnings on cycling head units.
I believe there is a push to put this tech in all mobile phones as well to help cars detect pedestrians. Not just autonomous vehicles, but manually driven ones with automatic braking. So its not just cyclists being targeted. Dog tags soon after that. Maybe squirrels.