The M-1 Rail streetcar project in Detroit said it's in talks with an unnamed donor that will provide an additional $5 million for the Woodward Avenue line's funding.

Project organizers are declining to name or characterize the donor other than to say it's a single entity.

"The nature of this specific contribution is not yet final, so it's too early to say exactly how it will be characterized," M-1 Rail spokesman Dan Lijana said via email.

The money is being counted already as part of the project's $187.3 million in funding to cover construction, administrative and operating costs. That's nearly $8 million more than M-1's funding total in 2014, which was $179.4 million. Also fueling the increase over the past two years is $1.4 million more from Detroit-based Quicken Loans Inc.; $1.4 million in additional proceeds from federal New Market Tax Credits; and interest.

The streetcar line's mix of private and public funding is from foundations, corporations, hospitals, universities, banks and governments.

M-1 Rail also disclosed that the $5 million naming rights fee paid by Quicken Loans to brand the 6.6-mile streetcar loop as the QLine was in place long before the deal was announced in May 2015. The money was factored into a 2014 funding source accounting provided to Crain's at the time, but its purpose wasn't disclosed.

"The naming agreement was prior to kickoff of construction in 2014," Lijana said.

That the online mortgage lender owned by Dan Gilbert bought the naming rights wasn't a surprise; Gilbert has been the streetcar project's co-chairman (with Roger Penske) nearly since its 2008 inception. Quicken is the largest financial contributor, at $11.4 million, after the Troy-based Kresge Foundation ($49.6 million) and a pair of federal grants totaling $37.2 million.

The streetcar project, which is expected to begin passenger service in the spring, has enough money on hand to cover its $142 million in capital costs. Operational costs remain a problem, however.

M-1 executives on Sept. 1 revealed that they have $21.4 million stashed away for operations, enough to cover seven years of service, but need to find enough for three more years, which would take the system through 2027. That's the year M-1 has agreed to turn over the system to the public Regional Transit Authority of Southeast Michigan, which will ask voters in Wayne, Oakland, Macomb and Washtenaw counties in November to approve a property tax that would raise $3 billion over 20 years to pay for improved mass transit, including the QLine's operations.

The streetcar line not having the full 10 years worth of operational funds banked spooked those involved in the RTA, and that organization in recent weeks opted to push back by three years the date when it would assume control of the streetcar line. It originally intended to take the line over in 2024.

M-1 estimates it will cost an average of $5.8 million to run the streetcar line during its first 10 years. M-1 Rail CEO Matt Cullen predicted that fares and other revenue, such as from advertising, will cover half of the operating costs each year, and the remainder would be paid from a reserve fund. Based on that formula, M-1 needs to raise $8.7 million for the reserve fund to cover the remaining three years of operations. That's predicated, too, on the ridership predictions to meet or exceed expectations.

To boost the reserve fund, Cullen said M-1 will approach larger employers along the route, which runs from Grand Boulevard to Congress Street, who would buy bulk passes for employees. That could include Wayne State University and the College for Creative Studies, and major employers such as hospitals and corporations.

Ridership in the first calendar year is expected to reach 1.8 million, and 5 million within five years, M-1 Rail COO Paul Childs said on Sept. 1. He noted that the numbers are rides, not unique numbers of passengers. Organizers predict 5,000-8,000 riders a day, with a basic one-way fare of $1.50. Yearly and other types of passes, including fare cards that link to other transit systems, still are being worked out, Childs said.

M-1's plan is a mostly curbside fixed-rail streetcar circulator system, co-mingled with traffic, with 20 stations at 12 stops. The two-car streetcar trains, operated by drivers, will move at the speed of traffic, and an end-to-end trip is predicted to take about 25 minutes, M-1 said.

Detroit's other major downtown transportation systems move millions of riders annually.

Last year, the Detroit People Mover carried 2.4 million passengers along its 2.9-mile elevated downtown loop. It has 13 stops and a full loop takes 15 minutes, using two-car automated trains. Its financial report for fiscal 2015 shows that it had $15 million in revenue but $22 million in expenses. The deficit was made up via $4.3 million from the state, $6.5 million from the city, and other smaller grants and subsidies. Farebox revenue last year was $1.4 million. A ride is 75 cents.

The Detroit Department of Transportation's No. 53 bus route on Woodward carries about 3 million passengers annually, the largest total of its 25 million annual riders systemwide. That translates into nearly 12,500 riders a day. The base DDOT fare is $1.50.