David Arquette, actor, producer director was just involved in a head-on collision and he's injured ... TMZ has learned. Wirnesses report that a car he was following suddenly stopped and he swerved left hiting a car in the opposite lane headon.

Arquette, who once bragged he tried alcohol at age 4 recently was in rehab for alcohol and other abuse. David was on his way to Burbank airport to board a private jet which was going to Las Vegas, for the grand opening of Sugar Factory -- a candy store at the Paris Hotel. He was supposed to attend a party hosted by Kim Kardashian.

The most recent report is he was gathered up by a local amergency crew and transported for treatment.

Police are still investigating.