The Brooklyn-Queens Connector has not made a single run yet, but it's already late.

The waterfront streetcar project is set to miss one of its first big deadlines, at the end of the month. It probably won't be the last, thanks to a systemic delay in the project's time line.

The city's Economic Development Corp. had planned to begin the public-review process for the streetcar by year's end. Instead, the agency is continuing to study the potential costs, revenue and overall feasibility of the line and likely will not start the review in the first quarter of next year.

"The BQX would be a multibillion-dollar investment bringing a modern and efficient transit option to communities along the waterfront," a spokesman said in a statement. "We're willing to take the time necessary for a thorough analysis to make sure it gets done right."

Mayor Bill de Blasio announced in February 2016 that the city was taking up the project, first promoted by Brooklyn real estate developers and transit advocates. But as officials took a closer look at the knot of infrastructure beneath the city's streets—installed by various entities for more than 100 years with little record keeping—they realized that coordinating its repairs and relocation could send the project's cost soaring beyond feasibility.

"There's about a billion-dollar swing one way or another depending on the level of utilities that are under the ground," EDC head James Patchett said in April at a Crain's conference. "We literally have people boring holes along the entire route right now."

Now the city is struggling to time the project in a way that wastes the least taxpayer money. Delaying the design and other initial costs in favor of a more robust study will save at least $35 million if the project is ultimately scrapped. But if it does move forward, EDC's initial caution would result in tens of millions of dollars in additional costs for every year the roughly $2.5 billion endeavor is pushed back, according to an internal memo from February reported by Politico New York.

"Likewise, by extending the construction start and completion dates, construction inflation (at 3.5% per year) costs will add roughly $100 million per year to the total project costs," the BQX project team wrote in the memo sent to Alicia Glen, deputy mayor for housing and economic development.

Exactly how long the 16-mile project will take is unclear. The EDC spokesman said that budgets and time lines tend to change for large and complex projects, and in this case it makes sense to do a more robust study upfront rather than leap into design and construction, even if it means costs are higher down the road. Once the results are in, the city will make an official decision about how to move forward.

The missed milestones and time line shifts suggest that the BQX's projected completion date in 2024 will be delayed by at least six months. But in addition to pushing back the public review, the city also failed to allocate $39 million into EDC's fiscal year 2018 budget needed to keep the project on schedule and never issued a request for proposals for preliminary design work. Meeting even the slowest schedule outlined in the memo, which translated to a one-and-a-half-year delay, entailed accomplishing some of these tasks while also allocating at least $15 million into the fiscal year 2018 budget and establishing a dedicated team to manage the project. Because these milestones also went unmet, the delays could be much longer than six months.