Plausibility exists as a device writers and directors can use to create a foundation, play with dynamics in tension and such. In this regard "Unstoppable" had me tortuously racked by its sustained implausibility. Were railroads operated so, there wouldn't be any: they would simply have destroyed themselves along with anything nearby. Those in the industry might well mistake "Unstoppable" for a fascicle comedy. Even "Towering Inferno" succeeded in more tense action than this.
Shot me - "Unstoppable" plays out like a Tele-Movie rather than something conceived for the cinema. The sound track, affects, camera are uninspired. The story is a string of absolute cliches.
What I'm left with is the site of that dimwit character who sets the whole thing in motion (good casting I have to to admit). He sits ensconced comfortably with his co-workers, like a group of buddies watching the Super-Bowl. Plausible real life would likely see him lynched before the an army of Police descended on him - arrested on multiple counts of Culpable Negligence, Manslaughter, Public Endangerment. A movie can be great and still plausible. Better for it in fact.
"Unstoppable" is as bad as action fodder gets.
Poor Poor Denzel Washington Jnr. What was he thinking.