I've decided to take the plunge and drive to Orlando for April vacation

I'lll be driving alone with 3 kids (dd12, ds11 and ds5). I plan on stopping in Raliegh, NC for the night, but would appreciate ideas for stops every 3-4 hours, such as fast food, play areas, rest stops. Thanks!
Do you have a membership with the local zoo, a nearby Children's museum, anything like that? When our kids were that age we'd stop at a children's museum with a reciprocal membership, eat our lunch in the museum cafeteria or nearby, then let the kids work off some steam at a new museum for free.

A lot of them were the perfect size for an hour or so. We've done a lot of zoos that way, as well, but less while on the road because zoos take longer for us.
Now we're members of a little museum in Lansing, MI that gets us into The Field Museum and the Museum of Science and Industry for free.

The Chicago museums still get money from us, though, because we generally pay for a temporary exhibit, and the kids
always buy stuff from the shops.

We live about two hours away from Chicago, which is a little too far to get good use of a membership to either Chicago museum (plus they are not reciprocal with each other), and memberships to those museum are much more expensive than the one we belong to, so even though we only get to Lansing once a year, that membership saves us a lot of money.
You can also get memberships with historical societies, arboretums, nature centers, etc. with reciprocal privileges. Something to consider if you like any of those.