It's budget season in city politics, which means compromise is in the air. Last Monday morning, the mayor demonstrated the art of giving a little -- but not too much -- inside Prospect Park near Grand Army Plaza.

Just a news cycle or two previous, an advocacy group was flanked by a half -dozen politicians in that exact same grassy triangle. On Thursday afternoon, Transportation Alternatives (TA), along with representatives from city, state, and federal legislative bodies, called for all non-emergency car traffic to be banned from Prospect Park on a trial basis this summer.

Currently, southbound traffic on the East Drive and northbound traffic on the West Drive is allowed for four hours every weekday, during the morning and evening rushes, from 7 to 9 a.m. and from 5 to 7 p.m.

"We've got to ban cars in Prospect Park and we've got to do it now," rallied Fort Greene City Councilwoman Letitia James. "When I grew up Prospect Park was my playground and I know what it's like to avoid those cars. I recall stories of many near misses. I don't want any child to have to fear coming to this park because of cars."

The mayor agrees, in principle, but in practice he is willing to initiate only a much tamer traffic reduction. Starting on June 5, for six months, southbound morning traffic on the East Drive will be closed, but northbound traffic on the West Drive will continue, and evening traffic in both directions will be preserved.

"We're doing this on a trial basis," reminded Hizzoner on Monday. "Let me emphasize the word 'trial.' If it does create real traffic problems outside the park we'll have to rethink it."

The emcee of Thursday's press conference was not impressed. "Any reduction of car hours is a step in the right direction," conceded Paul Steely White, executive director of TA. "But this plan improves the parks for relatively few users."

On Thursday, White's advocacy group released a study entitled, "Are Cars Driving the People Out? A study of pedestrian use patterns in Prospect Park." In it they interviewed 900 users of the park, and discovered that 82 percent of them would use the park more often if cars were banned during rush hours, which also corresponds with peak usage times of the park for exercise.The mayor's modest proposal was not what the politician's representing the area were hoping for.

"The time for a car-free Prospect Park is now," Park Slope City Councilman David Yassky urged on Thursday.

Carl Andrews, the state senator representing central Brooklyn and Prospect Park, also chimed in.

"Like Tish," he said, referring to James, "this was my backyard when I was growing up in Brooklyn. I join the chorus of elected officials here today to say, 'No More Cars!'"

U.S. Congressman Major Owen's district surrounds Prospect Park, and he sent his son, Chris Owens, to read a statement on his behalf at last week's press event.

"Today's report from Transportation Alternatives," read the younger Owens, who, along with Yassky and Andrews, is also a candidate to succeed his father, "is the second of this scope in less than ten years to clearly articulate the dangers posed by cars to pedestrians, as well as cyclists in the park. Though it is not necessary to have reports and studies to see the need for an immediate adjustment of car traffic in our park."

By Monday, the mayor had a quick response ready for these contrarian local pols and for the advocacy group which galvanized them.

"TransAlt wants to get rid of cars everywhere," smirked Hizzoner, "and that may be great for the environment and fun for everybody in the park, but most people don't want that. Nobody makes any bones about it. It would be better if you didn't have cars in the park, but during rush hour you would create chaos."

The mayor was flanked by Department of Transportaion (DOT) Commissioner Iris Weinshall, who, like James and Andrews a few days before, used the word "backyard" to describe Brooklyn's biggest park.

"Welcome to Brooklyn and welcome to my backyard," she told the assembled City Hall press corps. "I'm one of 15,000 people who use this park everyday. This pilot program will allow us to look at how traffic patterns change. We've been talking to Parks about this for many years. It's a collaborative effort of both agencies."

Parks Commissioner Adrian Benepe confirmed this collaboration.

"Iris walks in Prospect Park everyday and I bike in Central Park. She tells me about problems with the parks, and I tell her about potholes."

Given the admittedly constant and years-long collaboration between Weinshall and Benepe, the timing of the announcement of this limited pilot program did, however, follow closely and curiously on the heels of TA's report. But the notion of a car-free park has an even deeper relationship with Benepe.

"I remember when my father tired to get one car-free Sunday a month in the park," recalled Benepe fondly, "and people thought he was crazy. Now Prospect Park will be 85 percent car-free."

The announcement was also conveniently timed for the eve of a City Council hearing on the issue of car-free parks to be held by the Transportation Committee on Tuesday.

"We encourage the administration to go all the way and keep the vehicles out at all hours," said Transportation Committee Chairman John Liu in a statement issued Monday afternoon, "at least during the summertime when school is out and New Yorkers of all ages flock to the parks."

According to a recent DOT study, 1,362 cars use Prospect Park's northbound thoroughfare during the busiest hour in the morning, while 655 do so southbound. In the evening, 357 cars use it northbound, with 1,065 travel southbound. The decision to close off just the 655 reverse morning commuters, and not the less-dense afternoon reversers, was based on traffic patterns on the roads surrounding the park, according to Weinshall.

"These numbers are old, now we have new counters," she said, pointing to one just a few yards away, "so we should know better by the end of the summer."