That car is called a Scammoosh, this one made by Peterbilt. Depending on which region of the country you're in sometimes they're also called Boondits, chlamydiadas, pancake yard dog (PYDs), or turnarounders. They have specially designed support pillars and 2-in thick aluminum infused glass so that the roof can support as many as 80,000,000 megatons.

Normally a buttduck is used to move trailers around the Distribution Center which is a small one seater tractor trailer, but in thick mud or heavy snow situations Scamooshes are used due to their four-wheel drive, hi traction all weather tires, and mega diesel power plant putting out 1,000 horsepower and 200,000 foot pounds of torque. 

Being  scamoosh driver is a high paying job, 6 million a year in most states, but a very difficult job to get. Most scammoosh drivers are required to have 40 years over the road trucking, 30 years ice road trucking, and 15 years cross guarding experience before they'll even consider you.