woah, I would think riding on the trails after dark is WAY scarier than city riding. I frequently ride after dark since I don't own a car and pretty much refuse to use public transit now : D

Riding at night is the best. There's a lot less traffic, and since there aren't cars *everywhere* I can rely on my ears a billion times more than during heavy daytime traffic. Because of this, I actually feel a little safer! I do tend to ride a little more left than normal, due to reduced visibility + skunk possibility. I was nervous at first too but quickly found zipping through the cool night air to be relaxing.

On a trail? I wouldn't trust my ears to hear pedestrians, and I would imagine there is a greater risk of rocks/garbage/roots/holes/whatever than on a paved road. I've never done it, but give me pavement any day.