From that study
“The effect in twilight is based on only few accidents, and thus no conclusions about the effect could be drawn.
The hypothesis was that the effect would be greater in daylight than in the dark, but the results cannot confirm this hypothesis
This effect is of the same magnitude as the effect of the permanent running light
Some may argue that this effect seems unrealistically high. This may reflect a weakness in the study design: the fact that it was non-blinded and the use of self-reported accidents, which may result in response bias
Consequently, it is possible that the test group reported slightly fewer PIAs than they should because they wanted to prove the safety effect of the bicycle jacket.
”
Ignoring the other errors, basically if I turn my lights on when appropriate in poor light conditions, I’m sorted.