If you have to stop at a public place to pop a squat, where do you prefer? Lock if already posted. Didn't include buccees, because they are sparse. And way too obvious.
I had my gallbladder removed earlier this year and now I get the big D quite often, so I'm unfortunately becoming an expert in this. From your list, I'd vote Starbucks, hands down. They are single occupant and well maintained.
The back restrooms at super markets are usually decent. They have seat covers and usually only employees use them.
kinkos..open late. I know a hardcore druggie that does all his blow traveling around htown hitting up kinkos every ten feet. He knows every kinkos in the city.
i strategically plan my meals and dumps so i wont have to use public restrooms. are you aware peoples butts have touched those seats.
I typically look for the most deserted spot on campus. They're typically the cleanest. Then lay down 2-3 layers of toilet seat covers, and I'm good to go. Gotta do what you gotta do.
Banks and hotels. That's my list. My only concern is that someone is eventually gonna see me parked at one of these hotels and it gets back to the Mrs. Then I may have some 'splainin to do.
On the highway, stop at those mid-sized hotels like Holiday Inn Express, they always have good maid service. A lot of times you can get a free cup of coffee too. In between Houston and Austin try the Smithville Hospital. It's right on the highway and smells like bleach.