We're told Wayne and the other driver, a 51-year-old man, pulled over and things got heated ... in the form of an intense argument escalating into a physical altercation.
Cops say Wayne called 911 after the fight, and the other driver got back in his car and took off down PCH. We're told Sheriff deputies ultimately found the guy and ended up arresting him for battery, DUI and hit-and-run.
Wayne's got a rep for being one of the nicest guys in Hollywood -- outside of that hilarious "Chappelle Show" skit -- so it's pretty incredible someone allegedly got physical with him.
We're told the fire department responded to the scene, but Wayne was OK and didn't need to be taken to a hospital.
Sources close to Wayne tell TMZ ... he's banged up and sore the day after the incident, and will be taking it easy for the time being.