I am sorry but I had to post this. Icebreaker has a cool pair of tights listed on their site with the following description
"Articulated knees give you extra freedom of movement, while reflective graphics mean there's no danger of not being seen by passing cars when you're trail running at dusk."
Now I will admit that I run roads to get to my local trails but this made me laugh out loud when I read it. Not too much automobile traffic on my local singletrack :)