This 1977 movie by the same name is quite different.  It begins with a poorly represented Air Force missile base in the middle of the Mojave Desert.  There we meet two guys who form the core of the story: Denton, a fairly by-the-book military officer played by George Peppard, and Tanner, a fly-by-the-seat-of-his-pants hero played by Jan Michael Vincent.  They pass through various security points, are issued firearms, and sit inside a missile silo moments before the world is devastated by a nuclear exchange.  We're not really sure why, it just happens.  We soon learn that Denton doesn't like Tanner but is stuck with him since the world has ended with most American cities disappearing in huge mushroom clouds.

An unintended result of blasting the world to bits is that the planet is tilted off of its axis, resulting in even more deaths.  The sky, for reasons never explained, turns red and begins an amazingly strange light show.  Within this setting, the military survivors at the missile base try to maintain some sense of life in their hardened bunkers.  Tanner and his friend Keegan retire from the military during the intervening months.  Keegan spends his time painting while Tanner explores the landscape on his motorcycle.  Life proceeds after some fashion, with occasional interruptions from such problems as giant scorpions, until an airman falls asleep while smoking in bed next to a mass of pipes carrying flammable gas.  The base is consumed in the resulting fiery explosion.

Only four members, Keegan and Tanner, Denton, and his subordinate, Perry, survive the fire.  Denton opts to wheel out a project that he and Perry have been working on, two prototype "landmasters".  These huge, all-terrain vehicles with novel three-wheel arrangements are decked out with machine-guns and missile launchers. Denton declares that they are heading to Albany, New York, to locate the source of the only continuous radio signal heard since the nuclear exchange.

The teams head out, with Perry quickly getting killed in a storm and Denton having to transfer to the remaining Landmaster.  In Las Vegas, they stop at Circus Circus, and discover Janice, played by Dominique Sanda.  They take the only known living woman and proceed to Salt Lake City where Keegan is eaten by swarms of huge, deadly cockroaches that had been fortified by the nuclear fallout.  The killer cockroaches are actually a high point in the entire film.

The three escape Salt Lake to a shack where they find the  orphaned Billy, played by Jackie Earle Haley (better known for his role in The Bad News Bears).  Billy is deadly with thrown rocks but serves little other purpose.  He does help the team escape from a set of hillbilly mutants, similar to the pilgrims in The Outlaw Josey Wales, although these mutants have more lustful feelings for Janice.  When the conflict turns to violence, they prove they have shotguns.  Denton uses the missile launchers on the landmaster.  It really isn't a fair fight.

In Detroit they stop at a junkyard to find parts for the weary landmaster which is started to break down .  The sky begins to shift colors and change, with more energy flowing, probably for the same reasons the sky burst into flames in the movie Voyage to the Bottom of the Sea.  More storms rage and the Great Lakes empty onto the salvage yard.

Fortunately, the landmaster is water-tight and can float, and a good thing that is because while they are floating, doing their best Noah's Ark imitation, the Earth shifts back to its normal axis.  Moments later, a live voice crackles on the radio and announces that they are a radio station in Albany. 

Tanner and Billy ride out and find a pleasant community with about two dozen people who meet them in the streets.

Comment: Through the years, fans of the film have proven that the real star of the movie wasn't the actors but the landmaster.  The vehicle, created by Dean Jeffries Designs, sat in disrepair until July 2000 when it was salvaged through the efforts of two fans who completely restored the vehicle.