The economic and wisest path would be to make all public restrooms unisex.
I agree it is the most economic. As to whether is it the wisest is subject to debate. As I mentioned, the problem being, there are a LOT of parents that feel that their child's right to privacy in the restroom is violated when all the restrooms are made unisex.
Most school districts need the voters to pass a construction bond in order to fund the design and construction of new schools. If the voters are angry that the building that they agreed to fund has restrooms that (in their minds) violate their kids' right to privacy...they get pissed off. When they get pissed off, they tell the school district to bugger off when they try to pass the next bond to continue to replace their old buildings. That's not in the interest of the kids, as many of our buildings are over 60 years old, and at the end of their life. And, it's not in the interest of the district. Old buildings are expensive to operate, and don't provide great places to teach kids.
I talked with a transgender person (she works for the district) about the different approaches, and she recommended that we provide additional one-stall restrooms, and make them available to anyone that wanted to use them. The extra restrooms cost about $300K, on a $22M building. It wouldn't be that big of a hit, except construction costs have been going through the roof here, and we have already had to value engineer (<--truly a joke of a term) over $6M out of the project to stay within budget.
I'm not completely convinced that this is going to work well, but she (and many of the schools admins) do not believe that all unisex restrooms will be well received by the parents/voters. The school board wants to do what's best for kids, but they don't want to make the parents angry, either.
I guess we'll find out.
Go Blazers