Here’s how Jeff of Out With The Kids manages the frequent pit stop requests:
Next time your child calls out "Gotta Go!" – bypass the shady rest stop commode, port-a-potty and the dingy, dimly-lit gas station and their billy-club keychain, and head straight for a chain hotel. Each hotel is going to have available restrooms right in the lobby (usually around the corner from the front desk). These facilities are usually very clean, well stocked, and spacious.
As a bonus, if you are in a new town, grab some tourist literature on the way out. There is bound to be a brochure rack in the lobby as well. You never know, your child’s little pit stop may yield a future vacation or fun family outing that would have never been discovered otherwise!