Peter's large facial scar changes intensity throughout the film, even completely disappearing in some scenes.
After the race starts and the characters start talking, Garrity questions Stebbins if it's wise to be eating jelly sandwiches that early. In the background of this scene, the sandwich appears on Stebbins' hand out of nowhere, and he also fetches his water canteen from his bag, but in the next shot he's reached for it from under his other arm.
The film takes place in the 1970s. During the walk, a double stack intermodal freight train can be seen in the background. An all double stack freight train debuted in the U.S. in 1984. The movie is set in a dystopian future, not the 1970s, so technology from years after the books 1970s publication date is allowable.
The weapon that Pete is given at the end of the movie is mentioned as a carbine. However, the weapon is actually an M16 rifle, which is not a carbine. The carbine version of the M16 is the M4, which was developed in the 1980s and would not have been available for the characters to use since the movie is set in the 1970s. The movie is set in a dystopian future, not the 1970s, so technology from years after the books 1970s publication date is allowable.
If Raymond's family is able to live in a decent house and afford a car, then clearly the state of "economic hardship" the world is in can't be that bad.