The red truck changes from a dual axle drive to a single axle and then back again.
During the start of the movie, the train only has one locomotive. While in the collision scene, the train clearly has three at least. This is because the editors spliced in footage from 'Runaway Train' ca. 1985 to cut down on production costs. The collision scene, and most of the shots of the train moving across the landscape are taken from that movie.
Two F16 fighters take off, but in one shot they are an F16 and a Phantom.