A sign shows the new train that will run on the new Purple Line, during a groundbreaking ceremony on Aug. 28, 2017. (Oliver Contreras/For The Washington Post)

The light-rail Purple Line is designed to help commuters leave behind sluggish, unreliable buses and, for the first time, take a train directly between Maryland suburbs without having to ride Metro through the heart of Washington.

If all goes according to plan, passengers will step aboard in about five years.

But not much on the Purple Line project has gone according to plan — a court fight delayed construction by a year, and the project remains the focus of a federal lawsuit — and even supporters say motorists and residents along the 16-mile alignment should brace for some ugly construction.

Since the Aug. 28 groundbreaking, the project has moved at breakneck speed — and caught flak for it. Maryland transportation officials say they have to make up time lost to the legal delays. Meanwhile, local officials say they were blindsided last week when the state's contractor abruptly closed the popular Georgetown Branch Trail in Montgomery County for four to five years of construction after less than a week's notice.

Sen. Chris Van Hollen (D-Md.), a Purple Line supporter, wrote last week to Maryland Transportation Secretary Pete K. Rahn, "Unfortunately, the project seems to be off to a rocky start."

One day after the "Trail Closed" signs appeared, word spread that state officials had recently — and quietly — agreed to change the project's voluminous contract to cut from 30 days to seven the amount of time required to notify the public in advance of certain construction work.

That change prompted criticism from even longtime Purple Line supporters, who say they're worried the public is being kept in the dark on a construction project that will affect hundreds of thousands of people.

"They have to play by the rules," said Montgomery Council President Roger Berliner (D-Potomac-Bethesda), who first raised the public-notification issue. "If the rules have changed, they better let people know. They're off on a very bad foot."

Rahn confirmed the contract change Thursday when asked by reporters. He said the state and the main contractor on the project, a consortium of companies called Purple Line Transit Partners, can change the contract at any time by mutual agreement.

He said the trail-notification period was reduced to speed up work delayed by the legal case. He said the state would not agree to change parts of the contract that pertain to sound walls, landscaping and other mitigation measures that communities have been promised.

"I find it hard to believe that anyone didn't know the trail was going to be closed," Rahn said. "There's been talk about it clearly for over a year. I believe there's been more than enough notice about the trail's closure."

The previously undisclosed contract change didn't sit well with some local officials, including those representing residents who will have construction behind their back fences.

"This is a contract between the people of the state of Maryland and a private business consortium," said Mary Flynn, mayor of the Town of Chevy Chase. "There has to be some public accountability here."

Representatives for Purple Line Transit Partners (PLTP) declined to comment on the broader criticisms about project officials' openness so far.

However, they said the trail had to be shut down completely to allow workers and equipment to move safely along the construction corridor, where work will be done in different areas simultaneously.

"It's now become a work zone," PLTP spokesman Chris Doherty said.

Almost all of the Purple Line will run aboveground. East of the Georgetown Branch Trail, tracks will be embedded in — and stations will be built along — heavily congested roads. Those roads include University Boulevard, Kenilworth Avenue and East-West Highway in the Riverdale Park area.

In other cities where light-rail lines have been built, residents say the worst impact is the awful traffic caused by roads that are closed or narrowed so tracks can be put down and stations built.

Local officials say they've yet to see any construction schedules detailing when and where Purple Line work will be done or the plan listing which streets will have lane closures and when. Even so, they're beginning to prepare residents for a long haul. The line will be built between Bethesda in Montgomery and New Carrollton in Prince George's County.

"There's going to be a lot of inconvenience — I'm not going to pretend that's not the case," said Bradley Frome, a top aide on the project for Prince George's Executive Rushern L. Baker III (D). "But we're going to make sure our residents know exactly what the impacts are, where they are and what detours they need to follow to lessen those impacts as much as possible."

A key problem: The public officials closest to the residents and the motorists who will have to endure the construction appear to have little say in when and where construction will occur and how the public is notified. County officials refer questions to the Maryland Department of Transportation, which has begun referring all questions about construction to Purple Line Transit Partners. The consortium of private companies is building and will operate the line as part of a $5.6 billion, 36-year public-private partnership.

"It isn't clear who's calling the shots," Berliner said.

Ralph Bennett, president of Purple Line Now, said Maryland Transit Administration officials promised the group — the project's most ardent advocates — that the state would remain "out front" during construction. Instead, he said, it seems to be punting responsibility to its contractor. The group is a coalition of businesses, organizations, activists and residents.

Bennett questioned why the project's "community advisory teams" of residents have yet to meet and why no construction schedule has been publicly released.

"We're disappointed in MTA's apparent unwillingness to behave as the owners of this project," Bennett said. "You can't have the state saying, 'Sorry, this is the way it's going to be.' … They need to feel obligated to explain why they're doing things."

In Prince George's, about a dozen homes along East-West Highway in the Riverdale Park area have already been torn down to make way for a wider road with train tracks. Much of the construction already underway is on a train operations and maintenance facility in Glenridge, but the work isn't easily visible to passing motorists.

Prince George's County Council member Dannielle Glaros (D-Riverdale Park), a longtime Purple Line supporter, said her constituents along the construction corridor have a lot of questions about what's to come. She said she expects to see an updated construction schedule soon and wants to make sure residents know about job and contracting opportunities on the project.

"I think the plan for communication is still being dusted off," Glaros said. "Now that this is real — and it's a little hard to believe it's really happening — I think the key is getting MTA and Purple Line Transit Partners back out into the community."

A sign-up for project alerts is available under the "construction" tab on the project website at www.purplelinemd.com. The construction hotline is 240-424-5325.