A sign warning drivers that West Drive in Prospect Park is now permanently closed to traffic. View Full Caption NYC Dept. of Transportation

PARK SLOPE — The ban on cars on the west side of Prospect Park started Monday, giving joggers and bikers a bit more breathing room.

Cars are now permanently prohibited on West Drive, which runs from Grand Army Plaza to Park Circle. Previously drivers shared the road with park users on weekday evenings.

Mayor Bill de Blasio announced the ban last month along with a similar one in Central Park north of 72nd Street.

Activists have fought for years to rid the city's parks of cars, and their quest isn't over yet.

Vehicles are still allowed in the southern section of Central Park and on Prospect Park's East Drive on weekday mornings from 7 a.m. to 9 a.m.

Leaving East Drive out of Prospect Park's car ban angered some residents who felt the city was favoring the Park Slope side of the park. City officials said in June that more drivers use East Drive and banning cars could create safety problems on nearby streets.