What would it take to design a public toilet that doesn't devolve into a den of drugs, graffiti, and a parade of people who relieve themselves on the floor? That was the challenge facing the city of Portland, Oregon back in 2006, when city commissioner Randy Leonard decided to install sidewalk restrooms that would meet the population's need for relief without becoming a blight on the area.

Their solution was the Portland Loo. And more than a decade after the first Loo was installed, it's demonstrably one of the best approaches to providing facilities that remain clean and free from squalor.

Built by Madden Fabrication, the Loo addresses several of the most common issues facing restrooms open to citizens at large. Nothing about the design invites users to linger inside any longer than they need to in order to conduct their business. That's apparent as soon as you walk into the Loo and find a toilet but no sink. The absence of the latter is to prevent people from performing activities like washing clothes or grooming. (There's no mirror, either.) The only way to clean your hands is to use a spigot mounted on the exterior.

Courtesy of the Portland Loo

The Loo also does away with any sense of privacy. Bars on the top and bottom allow passing police to make sure people are adhering to the single-occupancy mandate and not cavorting. The bars also allow sound to carry. If you're inside, you won't really feel removed from the sidewalk or the passing pedestrians, and it's not likely you'll be relaxed enough to do much more than what nature requires.

In order to discourage drug use, the Loo uses a blue light that makes it difficult to locate veins for intravenous injections.

Vandals won't have much to do with the Loo, either. The coated stainless-steel surface resists spray paint and other markings.

The Loo has migrated to other locations around the country, including Cambridge, Massachusetts; Galveston, Texas; and Hoboken, New Jersey. Loos have also made it to Australia. The prefabricated units can run $100,000, with installation and maintenance costs extra. Later this year, Austin, Texas is set to debut two Loos sourced from Portland. The city plans to dub them the Waterloos.

[h/t CityLab]