theyare called super singles on highway trucks, the advantage is in weight savings and less rolling resistance increasing load capacity and fuel economy, tires and wheels are premium cost items.
here in michigan with our goofy wieght laws, 10 axles with duals plus the steer axle makes 154000 lbs gross legal without permits, the fat steer tires have been used for a long time on steel haulers and heavy haul construction trucks like dumps and concrete mixers.
I remember back in the late 70's early 80's tandem axle dumptrucks in the upper lower peninsula running used take off airplane tires on their drive axles for floatation and offroad traction in the swamps and sand, pretty awsome to see a loaded 13 yard dump back thru a 5 ft deep hole in soft sand and make it look like childs play