The rail idea has no counterpart study, but it has its advocates, like Assemblyman Phillip Goldfeder, whose district includes the Rockaways. They say it’s foolish to give up an existing right of way in a part of the borough so starved for mass transit. They have a point, but they may be understating the difficulty of reviving those rails for trains. Of the QueensWay’s 47 acres, seven are parkland. If the city, which owns the land, was to return it to the Metropolitan Transportation Authority for transit, it would have to find replacement parkland somewhere else. Then there is the question of when the M.T.A. would get to this capital project, which would be one of many on its overflowing, underfunded to-do list.

The likeliest answer is never. The M.T.A.’s capital plan is only half-funded; the agency is strapped by debt and is hard-pressed to protect the infrastructure it has.

When the Rockaway Beach line died, the L.I.R.R. was near insolvency. Both the railroad and the city have rebounded since then, but Queens is still undernourished in mass transit and park space. A wiser city would have made better investments in both, but that’s not the New York we live in. A tough choice has to be made. The city should choose the QueensWay as the more realistic possibility — but find other ways to ease the commute, perhaps with dedicated bus lines and other transit improvements that don’t rely on bottomless funding and a medieval-cathedral time horizon.

Mayor Bill de Blasio, who has announced a plan to rehabilitate dozens of neglected pocket-size parks in poorer parts of the city, should find the money to help the QueensWay boosters dream big. A $444,000 state grant announced in December should help the Trust for Public Land design the park’s first phase, in Rego Park. QueensWay is a bird in the hand, with lots more in those overgrown bushes. It is the rare chance to plug a spectacular park into a densely built streetscape that really needs it. Where there’s a way, there should be a will.