A recent issue of Store Brands magazine, on private-label food options for supermarkets, had a story on restrooms as an element of the supermarket store brand ("The bathroom: A significant store brand").
I wrote a brief piece this summer about the thing that surprised me the most about restrooms in public places, stores, museums, and train stations, was how compared to those places in the US, they were nice. Really nice.
-- "Restrooms as an element of the public realm"
Here, we think going to the bathroom is dirty, something to be hidden and embarrassed about, and so public restrooms are value engineered. And for the most part, a terrible aesthetic experience.
CityLab opines ("%Pay Toilets Are Illegal in Much of the U.S. They Shouldn't Be") that whether or not restrooms are free doesn't matter if restrooms aren't made available. The quest to make pay toilets illegal was successful, but it ended up creating different problems. And anti-human responses, for example, San Francisco paints streetlight poles with an additive that "spits back" urine onto a person urinating on the pole ("San Francisco uses 'pee-proof' paint," CNN).
Public restrooms in public spaces, like in Camden Town or Covent Garden, and at train and bus stations in London, did have a small charge. I don't think there was a charge at Selfridges Department Store, I can't remember. Probably there was at the V&A Museum. They had a room for baby strollers, and it cost to use that too.
If the alternative is none at all, I say, have a small charge.
But imagine if stores took Store Brand's advice and made the restroom experience a key element of the brand experience, like the pink bathrooms at V&A Museum.
Some places that have nice enough restrooms in DC are Eastern Market, the National Building Museum, and the National Gallery of Art.
When I first came to DC, 30+ years ago, and used the facility in the Mayflower Hotel, I was surprised there was an attendant. (I don't know if that's still the case.) The city's hotels tend to have decent restrooms.
Although judging by "how hard" the restrooms are used at Union Station in DC, I believe that the cost of running public restrooms isn't cheap.