Originally Posted by lanahk

Necessary? No, especially if you only ride in the daytime on paths. I feel better with a steady red light on the back, white light on the front, safety green shirt or jacket, and reflective gear. I use the lights less in the summer, but all the time in other seasons.

I've even taken to carrying a couple of cheap red blinkies with silicon fasteners in my pocket. I give them to kids riding their bikes on the streets or sidewalks. The parents are usually glad to have them.