When driving long distances you should stop and take a break every 1 to 2 hours.
You should not drive longer than 2 hours at a time without stopping to take a break.
You need to get out of the vehicle, stretch your legs, walk around, use the toilet etc.
If you have kids riding with you then you need to stop at least every hour or so and if the kid needs to pee or poop you should stop and let them do so.
I stop every 1 hour of driving when possible because any longer than 1 hour of driving my butt starts hurting and my leg starts hurting as well.
I need a restroom break every hour as well.
And if I see a gas station I go ahead and top off the gas tank even if it's not at half a tank yet.