Should've called the police. I carry a cellphone and am not afriad to dial 911 (000 for you I guess). That's assault with a deadly weapon- he purposely tried to force you off the road.
Although, I'm also kind of an a-hole in these situations (usually I'm smarter) and might have exchanged words with him when he pulled over and got out of the truck. Seriously, what was he planning? I'm guessing that if you did get into it and kicked his A he'd be mighty embarassed. Imagine the big bag trucker guy telling his friends he was beaten up by a guy wearing lycra shorts.
I do believe you made the right decision though. It's always better to walk (or ride) away from a confrontation. Nobody every really wins a fight...especially me as I'm not too big and certainly not a fighter.
PJ