Cannon Films didn't always produce grade B exploitation fare and lower. Sometimes they had loftier goals. Sometimes, they actually managed to get something truly good. This is one of those times.
Voight and Roberts get the majority of that duty and they acquit themselves admirably. Kenneth McMillan also chews some scenery as a railway operator trying to avert disaster. Kyle T. Heffner and T.K. Carter are his underlings and while Carter is okay, Heffner is just grating with his thoroughly unlikable tech whiz character. It's generally not a good sign when the evil warden slams a guy's head into a toilet he's been peeing in and the audience can sort of dig where he's coming from.
It only really mars the ending which goes for something a little more lyrical then the train crashing and while it works for the story, by the end of the movie you do sort of want to see it get smashed up real good. There are also a few annoying side characters as I noted above working to stop the train, but they don't hurt the overall effectiveness of the movie that much and you do get to see the most annoying one be on the receiving end of a toilet dunking.
The film is an intelligent, effective thriller that works about as well as one can hope a thriller could work. Cannon didn't always succeed when they aimed for respectability, but this is one of the rare instances where they hit the mark just fine.