Dallas and Fort Worth officials are moving forward on plans to create a separate entity to manage a potential high-speed connection between the two cities.

The Dallas City Council's Mobility Solutions, Infrastructure & Sustainability Committee gave city officials the green light to draft an agreement to create a local government corporation, known as an LGC, for the possible project with Fort Worth.

The committee hopes to see a draft of an interlocal agreement by early next year.

But a major question remains: whether Arlington or Grand Prairie will be part of the LGC. First, the cities would have to hop aboard one of the Fort Worth Transportation Authority, better known as The T, or Dallas Area Rapid Transit.

Michael Morris, the North Central Texas Council of Governments' transportation director, said joining one of the existing agencies — creating a new authority won't cut it — or contracting with them "in a significant way" will be "a litmus test."

"You're either going to be in the big leagues or you're not going to be in the big leagues," Morris said. "And Arlington knows if they're not fully compliant with this notion, there will not be a station on this high-speed rail line."

Otherwise, he said, the train — or possibly a hyperloop — would hum along unimpeded between the two cities.

Committee members strongly backed the line in the sand. Committee Chairman Lee Kleinman even wondered whether planting a high-speed rail stop in the mid-cities was the right thing to do.

"It would seem to me that if we're doing high-speed rail, which is sort of the cream of the transit industry, that we should do it to benefit the communities that have paid for transit historically for 30 or 40 years, which both Fort Worth and Dallas have," Kleinman said.

The project is still years down the road. Officials still don't know where the money will come from — the federal government, state government or a private entity. Morris said the LGC is needed "in case we get a $2 billion check from somebody and the state of Texas wishes not to cash it."

But regional officials envision a future where the line connects Texas Central Partners' planned Dallas-to-Houston high-speed rail line with a stop in Fort Worth along a potential Oklahoma City-to-Laredo high-speed rail.

Morris said the Dallas-to-Fort Worth connection is still undergoing an environmental review.

Texas Central Partners hopes to have its environmental impact statement published by mid-2018 and begin construction next year. The proposed Dallas station is set to be built in the Cedars neighborhood near Interstate 30.

Morris said a future connection to DFW International Airport is also an important piece of the project. It would be unfair to allow Arlington and Grand Prairie a rail connection to the airport without paying into a transit authority, Morris said.

Mark Duebner, Dallas' high-speed rail project manager, said Dallas council members will also have myriad issues to consider, such as governance, property acquisition rights and how much veto power the City Council would have if a third city joins the LGC.

But Morris didn't believe both cities would ultimately step up. He believes Arlington is more likely than Grand Prairie to join DART or the T.

Walter Shumac, Grand Prairie's transportation director, said the city wants to keep its options open and remain at the table in the discussion, but does not currently have any plans to join a transit authority.

But if both cities do end up joining, Arlington and Grand Prairie would share a high-speed rail stop.

"Under no circumstances would there be four [stations]," Morris said.

Laura Hanna, spokeswoman for The T, said the agency has had "numerous discussions" with about transportation issues with Arlington in recent years. DART spokesman Morgan Lyons said the agency has also had talks with Arlington, but didn't know what the next steps would be. Arlington does not have a full cent of its sales tax to contribute to DART, which the agency requires for membership.

An Arlington spokeswoman did not immediately return a request for comment Monday. Morris said an Arlington citizens committee has looked at transit options, and the city is having "great conversations" with both transit agencies.

Arlington currently contracts with the T and DART for one bus route between the University of Texas at Arlington campus and the Trinity Railway Express Centreport Station. But the city is going to discontinue that service next month "and do something else," Lyons said. But Lyons is not sure what that will be.

"Arlington has got to make some decisions about what they want," Lyons said.

Update: Revised at 7:55 p.m. to include comments from The T's spokeswoman.