Sarah Gardner: Boston is a very old city, at least in American terms. But it's now got a whole department dedicated to city innovation. It's called the Office of New Urban Mechanics.

And that office just found a fix for reporting one of the oldest and most lowly of city problems: the pothole.

WBUR's Monica Brady-Myerov explains.

Monica Brady-Myerov: People use smartphone applications for games, cooking, working out, pretty much anything. Now Boston wants anyone who drives in the city to use their smartphones to report potholes -- as they pass over them.

Boston’s new app is called Street Bump. I wanted to see it in action. So I asked a city worker who's an early tester to drive me around. Michael Dennehy knew just the street to go to.

Michael Dennehy: We've just crossed the James Kelly bridge heading into South Boston.

Soon enough, we hit a rough patch. And the app starts to record each big bump with an electronic chime.

Brady-Myerov: It's not picking up the small vibrations that I'm feeling but it is feeling the larger ones.

Dennehy: And that's what we've found. If you see something that we're approaching that you think should get a bump, nine times out of 10 we did receive the bump.

Here's how it works. When the app is on, the phone senses the car’s movement and speed, and tells when you hit a big bump. It pegs the location using GPS. At the end of the trip, you press a button to upload the data and voilà, you've just reported the exact location of a pothole to the City of Boston. When three people report the same problem, it’s automatically sent to a pothole fix-it list.

Nigel Jacob: This only works because we're actually pretty good at filling potholes.

Nigel Jacob is co-chair of the mayor's Office of New Urban Mechanics. He says Boston workers fill reported potholes within a day and a half. His office spent $80,000 to develop the app. But Jacob says the program isn't just about fixing streets. It's about connecting residents with city services.

Jacob: This is a way to engage the public in a new more effective way and shore up the trust that we are trying to deliver a valuable service.

Residents here have been using free city apps to report other problems. One allows you to email a picture of graffiti or a broken streetlight and file a report. Boston has tested Street Bump in other cities in California and New York, and it works. They’re giving away the code so those cities can use it to find and fix potholes.

Jacobs says these apps will transform the way residents see their city services in action.

In Boston, I'm Monica Brady-Myerov for Marketplace.