Originally Posted by
exile
In theory it sounds like a novel idea, but in practice it doesn't sound like it would work as intended.
By the time a driver is close enough to see a flashlight reflecting on a cyclist their headlights will far outshine the flashlight, illuminating the reflective gear themselves.
But, red lights pointed backwards are very effective, especially when combined with reflective material to give more shape to a cyclist. There are a lot of red lights on the road and I'd hate to have mine blend in with the brake lights of the car in front of me.