I was with my friend on the Red Line leaving Ashmont. “I have to use the bathroom,” they said. And I…had no idea where any bathrooms were. I knew there was one at South Station, but were there any before that? “If only someone had made a map showing all of the public bathrooms on the T,” I thought.

Now that map exists! A female friend and I went around the whole system to every station with fare control snapping photos of and taking notes about all the bathrooms we could find. I then compiled them into an interactive map (with lots of info about each one) and a cobbled-together MS Paint version of the official MBTA map (in case you really gotta go and don’t want to futz around with that interactive map stuff). Here’s the diagrammatic one (I’ll explain the icons in more detail below):

And here’s the interactive Google map (or click here, which seems to work a lot better):

Firstly, the colors. Green means that the station is inside fare control, as in you have to be on the paid side of the fare gates in order to access it. Red is the opposite, meaning that you have to leave the fare gates to get to that bathroom (or if you happen to be in the area – lucky you, it’s a public restroom!).

The numbers represent a somewhat subjective rating system. We scored each bathroom on a 1 to 3 scale, with 3 being the best and 1 being the worst. You might disagree with our scores (everyone’s tolerance for grossness is different), but they should give you a rough idea of what you’re getting yourself into. They also only represent the conditions when we were there – things may have changed since then.

The interactive map adds some more info about each bathroom. You can click on one to see whether it’s single-stall or multiple-stall, whether or not it’s gendered, some notes about its condition, and photos. There’s also a hidden layer of bathrooms that look public but are locked (or at least, they were locked when we came through) – open up the map description and check off that layer if you want to see those.

UPDATE: A note on our rules. I should’ve done a better job explaining which bathrooms we count and which ones we don’t. Our rules were MBTA property only (thus excluding the Macy’s that connects to Downtown Crossing, for example), and bathrooms that can be accessed by the public without needing to ask anyone. There are a lot of unmarked employee bathrooms around the system that the public could use if they asked nicely and the employee on hand was willing to let them, but we didn’t want to count those cases because a number of factors dictate whether or not you can use them. Bathrooms that look public but aren’t appear in the “Locked Bathrooms” layer in the interactive map.

So if you know someone with a tendency to have to use the bathroom often (but let’s be real, we all have emergencies), send this to them! Now they’ll be able to know everywhere on the MBTA where they can go.