You may have more room in a semi but you are confined to the truck and the truckstop to a very large degree. With the van you are "confined" to the museum, library, park, zoo, theater, diner and anywhere else you can think of. You are not stuck sitting in the van waiting for the next load. You set it up with the company to be off satellite and on cellular and any decent company will have that option and call your cell phone.
But doesn't Fedex and Panther have that restriction in play that starts a Van Drivers "Hours" the minute the van is moved for any reason??? Let's say you get a good 8 hours sleep at Wally World. Wake up all rested, start your van and run to the closest truckstop for a shower. From what I understand, your "16 hour clock" starts the minute you leave wally world, and not when you get dispatched for a run that comes up. So now lets say you are well rested and decide to go to that "Museum". Museum is 12 miles away, you take that drive and it suddenly puts you in 6th place in line instead of 3rd because your traveling time to that museum is logged there on Fedex's computer.
I've heard of too many stories HERE of where drivers hours and places in line were cut because they decided to go 2 blocks to grab a Jack-in-the-Crack hamburger instead of eating the crackers and olives they had in the truck.
So...to me IT DOES sound like that YES, you are stuck to sitting on your van waiting for that next load unless you put yourself OOS, go do your quick sightseeing, and then putting yourself back in service and possibly last place in line when you started your day 2nd or 3rd in line.
This could also be a deciding factor on WHO one may want to run for, know what I mean. Too many variables in play with both the big named companies(FED-Panther) that negatively effect a drivers income while they are under contract with them.
Personally, if I ever give CV Expediting a try, the Fed and Panther would my last 2 choices to apply at.