I'd be surprised if this hasn't been posted/linked to previously on the forum. But I did a quick search and didn't find it, so I thought I'd post it up.
While researching adding auxiliary LED lights to my Wee, I ran across a motorcycle-specific 2011 study conducted by the NHTSA.
Motorcycle Conspicuity and The Effect of Auxiliary Forward Lighting
They tested the assessments of left-turning drivers as to whether it was safe to turn as vehicles (including motorcycles) approached. The motorcycles were equipped with various forms of auxiliary forward lighting: low-mounted lights, high-mounted lights, fork-mounted LED arrays, and modulated headlights.
The report is super detailed, and contains WAYYY more information than my short attention span is capable of dealing with. But a quick glance shows some interesting results.
If I'm reading it correctly, auxiliary forward lighting wasn't shown to increase the safety margin (in terms of distance). However
, and most importantly, the data suggested that added forward lighting did decrease the probability of drivers turning in front of a motorcycle with an "unsafe safety margin".
The relevant quote from the Conclusion section (highlighting mine):
"Although the results of this study did not provide any evidence that the experimental lighting
treatments on the motorcycle influenced the mean safety margin (judgment of the last safe
moment to turn in front of an approaching motorcycle), there was evidence that the experimental
lighting treatments significantly reduced the occurrence of short safety margins. This suggests
that enhancing the forward lighting on motorcycles during the daytime may be effective at
reducing the probability that drivers will turn in front of the motorcycle
with an unsafe short
safety margin. "
It might make for interesting reading for someone with a more developed frontal lobe and a longer attention spa.....SQUIRREL!!