The Tooshlights system shows where you can go.
There's money in smart public restrooms too: Speaking of funding, here's a name that got some more: Tooshlights. The company provides indicator lights that are wirelessly connected to bathroom stall latches so "you know where to go." The idea here is to expedite and optimize public restroom traffic flows at restaurants, stadiums and other large venues. Tooshlights raised $3M in a Series A round led by Texas-based convenience store Buc-ee's, LTD. I'd surely find it convenient to see that green "your toilet is available" light while on a road trip.