Concerned the city might not follow through on its Vision Zero plan to eliminate traffic fatalities — and that promised Slow Zones might not be implemented — the activist group Right of Way, on Sunday, put up 20-mile-per-hour signs in 11 neighborhoods around town. Above, they attached the signs to poles in the Hudson Square neighborhood. They don’t want the exact locations printed in hopes the signs will stay up longer. The West and East Villages are among neighborhoods slated to get Slow Zones, which feature street humps near schools, lower speed limits and other traffic-calming measures. Pedestrians and cyclists are much more likely to survive a car accident if the car is traveling 20 m.p.h. versus 30 m.p.h., the advocates say. Mayor de Blasio has asked the state to authorize the city’s lowering its speed limit from 30 m.p.h. to 25 m.p.h. Uptown Assemblymember Danny O’Donnell is sponsoring a bill to cap the speed limit at 20 m.p.h.