Apparently, Chad Caruso set the Guinness world record as the first person to skateboard across America in 2023, from Venice Beach to Virginia Beach. It took him 57 days to cover 3,162 miles, adventure adventure of 55 miles a day.
My guess is that hitchhiking+skateboarding means grabbing an actual moving trailer hitch or three. Were he manually kicking the pavement with zero assistance, I cannot imagine covering 55 miles a day without it being downhill the entire time. After all, it is F L A T after you cross the Rockies. For at least a thousand miles. That or he has legs like tree trunks.