Trust me, I wish we had been able to get more information on this jackass,
That's OK. Your safety comes first. Always. Being able to report someone is nice if you can do it, but your safety is waaaay more important.
Someone who makes a habit of driving like that is going to be noticed by enough people that he gets reported eventually. Hopefully before before he gets someone killed.
What blas said about getting out of the way is very sound advice. Yes, it's pretty damn annoying to have some asshole breaking the law and having to let them get away with it.
Trust me. You'll get over that a lot faster than you'll get over being hit by a semi. I guarantee it.