Robbiee,
Apparently you do not know much about the Trucking Operation run by Walmart.
They run from Walmart Distribution Centers to Walmart Stores with the occasional stop on the way back to the DC to pick up drop and hook trailers at major suppliers to the DC's.
Rarely do they sleep in the trucks and when they do...they get paid extra for that.
For your standard Over the Road Truckers....you are closer to correct depending upon the Operator....and kind of hauling being done.
UPS over the road truckers work from Hubs and live at home....and have work days just as standard occupations do....and make excellent salaries with the usual Teamster benefits.
Trucking ain't all about Flying J's and Lot Lizards.