BANGOR, Maine — The city’s planning board voted Tuesday to deny a site development plan to modify the former 3rd District Court building on Hammond Street, a decision that could affect the U.S. Postal Service’s plans to move into that space.

Planning board members said concerns over parking and pedestrian safety prevented support of the plan, which included a 22-by-25-foot loading dock and reconfigured parking spaces.

No one from the U.S. Postal Service attended Tuesday’s meeting, so it was unclear whether the planning board’s decision affects plans to move the city post office. Penobscot County Administrator Bill Collins represented the applicant, Penobscot County, which is prepared to lease space in the building to the postal service, but he declined to speak for the potential tenant.

City Planner Dave Gould told planning board members before the vote that since the site already is zoned for that type of use, the post office could move in there tomorrow if it wanted. However, any exterior changes to the site would need planning board approval.

Planning board members said they couldn’t support the proposed changes because they didn’t address parking and safety concerns. Members Miles Theeman and Andrew Sturgeon were especially critical of the plan.

“I think we need to exercise some common sense here,” Theeman said.

John Kenney with WBRC Architects-Engineers, a Bangor firm that was contracted to make the site improvements, said the building operated for many years as a District Court. In that sense, he argued, it already dealt with heavy traffic. Planning board Chairman Allie Brown, however, pointed out that District Court traffic was not as constant as potential post office traffic.

The former District Court site faces both Hammond and Franklin streets. It abuts the Penobscot County Jail and the Penobscot County Courthouse, which also are owned and operated by the county. Parking on-site is limited and tough to navigate, which also has been among the biggest concerns about the current Bangor post office site — the Margaret Chase Smith Federal Building on Harlow Street.

The federal government recently launched a $53 million renovation of the federal building and requested that the post office vacate its space by May 1.

Last month, Postal Service officials visited Bangor to tour a handful of potential sites, including the former court building, the former Miller’s Restaurant and temporary Hollywood Slots facility on Main Street, and empty space at the Bangor Daily News building, also on Main Street.

Late last week, county and post office officials confirmed that the former District Court building was a potential site, but both sides said the deal was not done.