Originally Posted by
jon c.
I see no data there addressing the point in question.
Sometimes, we need to use our own eyes and common sense.
While on the road, make note of traffic especially bicycles and motorcycles. Decide for yourself whether daytime lights make them stand out better or not.
Of course, standing out and catching people's attention doesn't guarranty reduced likelihood of collision, nor could we determine the extent of collision reduction without controlled testing. However, I doubt there's any serious debate as to whether daytime lights help at least a bit.