The Civilian Minihauler, or Miner Minihauler, is a vehicle used commonly by colonists across Tharsis around the time of the Second Martian Revolution. It is very slow compared to every other vehicle that is not a tank, severely lacks for durability, and can only hold two people, the driver and one passenger sitting on the bed.
It is likely that the Minihauler (So named for its entry as such in the game files,) serves the purpose of a Martian personal mobility vehicle and/or grocery getter, for short trips around the neighborhood where a full-sized civilian vehicle would be excessive. Alec Mason is arguably better off walking than driving this vehicle, as whilst it is marginally faster flat-out than his running speed, it is significantly less agile, and it can be taken from full health to destroyed very easily, quite likely killing Mason (from the Minihauler's explosion) outright from an attack that he could well have survived, if not dodged completely, on foot.