Would You Take A Crap In This Rolling Porta-Potty?S

While watching the massive boulder-hauling through Los Angeles the other night I noticed something striking at the tail end of the procession of heavy vehicles.

Yes, that's a porta-potty pulled by this truck.

Presumably the toilet's for on-the-go bladder and bowel-voiding needs of the many workers walking alongside the boulder-hauling rig.

But after seeing it, I'm now a little curious about the micturating/evacuating process at 5mph on a trailer. I wonder if they stand to pee, or does sitting make more sense when in motion? Can you comfortably eject waste while slowly rolling along? Now I regret not running up to find out.