You may have noticed that your neighborhood has gotten one or more speed bumps installed of late.

One, your impressions are correct. The city of Detroit began installing these traffic calming obstacles on residential streets in Detroit last year through a pilot program that’s expanded this year.

Two, they’re actually called speed “humps” or “cushions,” depending on whether they stretch across the length of the street (hump) or are rubber additions that come in sections (cushions). Either way, they have less of an incline than a speed “bump,” and therefore a reduced chance of doing damage to your car.

But whether it’s a hump or cushion, warning signs will say “Hump Ahead” or “Speed Hump” to reduce confusion.

According to Caitlin Marcon, deputy director at the city’s Department of Public Works, the hump program began because residents were calling for it. “Speeding on residential streets is one of the top complaints we get,” she says. “Not only our department—the Detroit Police Department’s Traffic Division reports the same thing.”

Soon after the program was announced, requests for speed humps came flooding in. “The minute it was launched, we started getting calls for how to get them installed,” Marcon says.

She adds that in the first week the department got around 100 requests per day from the online portal alone. In total, they’ve gotten about 2,500 hump requests.

The post-pilot phase got a $2 million budget allocation. So far, DPW has installed humps on over 400 blocks and will continue to add more through the end of the year.

Locations were determined by a street’s proximity to schools and parks; if there are more speeding violations and traffic; and through input from City Council, the Detroit Police Department, and other residents.

DPW says it hasn’t been collecting data long enough to determine if the program has measurably reduced the number of accidents. Through Marcon says the department has gotten a number of “thank you” cards and calls from residents saying they’re working.

Additional funds have not yet been budgeted for the program in 2020. But Marcon says that, because of its popularity, she doesn’t see it going away anytime soon.