12 hours of sitting with 3 5 minutes stops is unbelievably bad for you. 12 straight hours of driving is unbelievably bad for you. None of that should happen, ever. Even if it's your job. It's bad for so many reasons. If you frequently subject yourself to this, you actually need to be forced to take more longer breaks, your body and mind will say thank you for it. 12 to 15.5 is hardly through the roof, it's what, 25% increase? It honestly should be more.