Planning ahead for rest stops on a road trip before you leave on the road trip is a good idea.
This way you know where the rest stops are and then you can have a planned stop to take a break, get gasoline, eat, change diapers if you have kids in diapers etc.
If you have kids in diapers you'll need to stop to change their diapers and if the kids are not in diapers then they will need to stop more often to use the toilet.
Kids bladders are smaller and you'll need to stop more often to allow the kids to pee.
If you have no kids then you can drive as long as you can or want but it's recommended to stop at least every 2 hours.
When driving on road trips or driving long distances it's recommended to take a 20 to 30 minute break if possible for every 2 hours of driving time.
Driving 2 hours at a time can get very tiring and your legs and feet may also fall asleep.
You need to pull off the road and take a break and walk around, eat something, check your vehicles fluids etc before getting back on the road.
I usually drive only about 1 hour at a time and then pull off the road into a gas station or other rest area to take a break and get some gasoline.
I stay there taking a break for at least 20 minutes and walk around and then get back on the road again.
I've tried driving 2 hours at a time and I got so tired and almost went off the road one day.
So I drive only 1 hour to 1 hour and 30 minutes at the most and then take 20 to 30 minute breaks.
I'm usually in no hurry to get to where I'm going especially if I'm on a road trip for fun.