West Coast Sand & Gravel Inc

I was driving west on the 91 Freeway then I saw a West Coast Sand and gravel truck trying to get on the freeway I backed off to let him in I then I started to pass him in the left and he tried to cut in front of me and all most crushed me into a car to my left before he backed off. I blew my horn to warn him and he blew his loud horn and thew me the finger. This was approx. 5:25 PM on Monday night. It was around the Pioneer and Norwalk on ramps. He was around 30years old w/dark hair. He's going to kill someone. He should be fired.