Prospect Park will be completely car-free from July 17 through September 10, Mayor de Blasio and DOT Commissioner Polly Trottenberg announced this morning. It’s the first time since the campaigns to get cars out of Central Park and Prospect Park began generations ago that either one will cease to be a shortcut for car traffic for more than a few days at a time.

The two-month trial will get car traffic off the East Drive of the park, where it is currently permitted during the morning rush on weekdays between 7 a.m. and 9 a.m. The city says it will study traffic impacts before deciding whether to make the park car-free year-round.

The park’s West Drive has been off limits to general car traffic since July 2015, but one lane of the East Drive, near less affluent communities in Crown Heights, Prospect Lefferts Gardens, and Flatbush, has remained open to weekday rush hour traffic between 7 a.m. and 9 a.m.

DOT has said that higher traffic volumes on the East Drive are the reason it didn’t make that side of the park car-free. But at this point, not many people are driving through the park. Fewer than 300 motorists per hour use the East Drive when it’s open to car traffic, compared to more than 1,000 people biking, walking, and jogging there, according to DOT.

“We’re going to make this change over the summer, we’re going to collect data, see how it works in terms of traffic and safety, but we think it’s going to be tremendously popular,” Trottenberg said at a press conference this morning at the park’s Grand Army Plaza entrance.

The agency said traffic studies after the West Drive went car-free have shown that typical car travel times increased by about a minute on the most trafficked route around the park, and decreased on some other routes.

It’s not clear what conditions will have to be met for DOT to decide to make the park car-free all year, or when the agency will reach a conclusion.

In Central Park, meanwhile, car traffic is still permitted on 72nd Street and below.

Many years of advocacy and several campaigns for a car-free Prospect Park led up to this moment, chipping away at the times and locations where cars are allowed. In 2002, volunteers with Transportation Alternatives collected 10,000 signatures to get cars out of the park and got every City Council member abutting the park to endorse a summer trial. Here’s a look at the demonstrations from those campaigns:

In 2008, volunteer high school students with TransAlt’s Prospect Park Youth Advocates campaign collected over 10,000 signatures in favor of a car-free Prospect Park:

Then-Brooklyn Borough President Marty Markowitz opposed the idea. But Eric Adams, the current borough president, has pushed DOT to try out a completely car-free park.

“Parks are for people, and people from all across Brooklyn and beyond will enjoy a safer and more serene Prospect Park as a result of this initiative,” Adams said in a statement today.