One day each week, the block of Bartlett Street between 21st and 22nd Streets bustles for a few hours when it’s transformed into the Mission Community Market. On all the other days, however, it mostly serves as a parking lot.

The Planning Department and organizers from the Community Market held a packed public meeting yesterday to start off the design process for the Mercado Plaza project, which would include greenery and physical traffic calming improvements to make the block a more inviting place to be at all hours.

“The idea is to transform an overly wide street into a street with much more amenities for public space where kids can play, families can get together, and bringing more culture to the street,” said Ilaria Salvadori of the Planning Department’s City Design Group.

“It’s hard to overstate the need for that kind of public space, especially in the Mission,” said ‘Deep Jawa, a neighbor who is known for building a parklet on the curb space in front of his home. “If you look at Dolores Park, you can see how it has become the Mission’s congregation space. The idea of building a new public gathering space is incredibly exciting.”

Narrowing the wide roadway on the one-way street is key to the expansion of public space and the traffic calming effect planners hope to achieve. Under the block’s redesign, planners propose narrowing the existing traffic lane to 14 feet wide and, where car parking is retained, a 7-foot-wide parking lane.

But changes to road widths must be cleared by the Fire Department, which generally follows state standards that require a 20-foot wide unobstructed roadway for fire truck access. However, the department approves projects on a case-by-case basis, said Patrick Siegman, a principal at the transportation planning firm Nelson/Nygaard.

With a new package of proposed legislation, Supervisor Scott Wiener hopes to cut through some of the bureaucratic red tape that hinders pedestrian safety improvements. That includes the 20-foot fire code standard, which Wiener said doesn’t always make sense in a dense city. His legislation, which goes up for initial committee approval on Monday, would help clarify what the city considers an obstruction, since features like curbs can usually be mounted by a fire truck, he said.

“The fire code can at times be one-size-fits-all, and tends to be fairly suburban in nature, in terms of wider streets and being car-focused,” he said. “We have a lot of streets that are heck of a lot narrower than 20 feet, and we also have a lot of streets that could really benefit from sidewalk widenings.”

Siegman, who was consulted in drafting Wiener’s legislation, said the state-adopted fire codes are crafted by the International Code Council, a Texas-based nonprofit. The regulations do allow for local municipalities to determine what counts as unobstructed roadway, and they don’t apply retroactively to streets that are narrower than 20 feet, he said. Requests for comment from SF Fire Marshal Thomas Harvey weren’t returned.

If the proposed Bartlett project doesn’t get the Fire Department’s approval, Salvadori said planners may also have to remove more parking from the block. With roughly 27 of the block’s 40 parking spaces already proposed to be removed, it remains unclear how taking out more would fly with residents.

At yesterday’s community meeting, only one woman complained about losing parking, arguing that some elderly residents need their cars. She identified herself as a member of the Liberty Hill Neighborhood Association, which opposed the nearby condo project at 1050 Valencia Street last September because it didn’t include any parking. A couple of folks wearing “Save Polk St.” T-shirts were also spotted at the meeting.

But the woman’s complaints didn’t seem to resonate with many attendees, who applauded when a man pointed out that the 350-space parking garage at Bartlett and 21st is underused. Some attendees called for removing more parking.

“It’s just the standard smoke and mirrors from the parking-at-all-costs crowd, and I’m tired of it,” said Jawa, who is a member of LHNA.

“I understand that some people need access to cars,” he said. “The issue is balance. But no one ever talks about the fundamental balance of our society, which is that we have spent the last hundred years building out our infrastructure for cars. We give away parking spaces, practically.”

“It’s not about taking away your stuff, it’s about: does this space serve the public as well as it can? Parking a car in a space, as opposed to having community space, is not a fair trade-off.”

The project will be funded by $1.6 million in Prop B bond funds and the developers of the nearby New Mission Theatre project. Construction is expected to begin in mid-2014.