Several years ago I had someone pass me on the W&OD in the winter, sans lights. As he passed, I asked if he usually ran without lights in the dark, and he said something like “yeah, I’m only going a few miles”. A mile or so later, I came across him and another rider sprawled in the middle of the trail. No-lights guy apparently couldn’t tell what lane the oncoming rider was in (oncoming rider had lights) and swerved into his path at the last minute and they hit each other head on. Fortunately nobody was injured. Some people are idiots.