Ok this is not the best movie ever made, but taken from a book by Roger Zelazny and with a script written by Lukas Heller (Dirty Dozen, Flight of the Phoenix) it has a lot going for it.
This is a post apocalyptic movie starring George Peppard and Jan Michael Vincent. The third world war kicks off as the movie begins and we follow a team in a missile silo launching the nukes.
After the war the earth is laid waste and the group set about surviving at their military base. After a while, it appears simply out of boredom, they set off in massive land vehicles in search of a mysterious signal.
Now you might be saying, I have heard all this pretty much before, but remember Damnation Alley used this plot line back in the seventies.