"It's now or never."

The old Elvis Presley ballad wafted through speakers in a City Hall conference room shortly before Mayor Mufi Hannemann announced new details on Monday about a multibillion-dollar rail mass transit plan for O'ahu.

And Hannemann is singing a very similar tune as he prepares for a showdown with the City Council over the scope of the project and how quickly key decisions should be made.

Hannemann warned yesterday that if the council derails the plan — as happened to a similar project in 1992 — he won't try to revive it again. He has repeated another warning like a mantra: "The longer we delay, the more we're gonna pay."

The council will quiz Hannemann's administration today about details of a transit study that outlines two mass-transit options: a 20-mile route that would cost $3.6 billion and run from East Kapolei to Ala Moana Center; and a 28-mile system for $4.6 billion from Kapolei to Manoa.

Most council members seem to favor mass transit, but some say it's not necessary to decide on specific details before January, when a general excise tax increase is scheduled to take effect on O'ahu to help finance the project.

Council chairman Donovan Dela Cruz said he believes there should be a decision by then on the system's length, transit mode, and beginning and ending points.

But a decision on the specific alignment — the exact path along streets and highways — should wait until residents have more time to review the plan, he said. The locations of transit stations also should be carefully considered, he said.

"We have a responsibility to engage the community and review the impacts that each station will have," Dela Cruz said. "My understanding is that the alignment can be (decided) later."

Hannemann said that's not the case. Though it's not necessary to decide by January on locations of all stations, it's crucial to decide on a specific alignment before then, he said.

"It's not enough to say you're going to go from point to point," Hannemann said.

The city has studied dozens of potential routes and evaluated their characteristics and advantages. Moving the alignment to paths other than those could delay the project and increase its cost, Hannemann said.

Dela Cruz said he and three other council members will travel to Washington, D.C., on Nov. 11 to meet with federal transit officials and clarify how soon such decisions must be made to qualify for federal financing assistance.

Dela Cruz said it's unnecessary for Hannemann to pressure the council.

"I think he should let the process occur, and he's more than welcome to participate in the process," Dela Cruz said.

Building along the studied routes would require the city to acquire dozens of privately owned land parcels. And the value of many parcels along the chosen route is expected to skyrocket, according to the study Hannemann unveiled Monday.

Hannemann said the city would acquire land by condemnation — forcing the owner to sell at a fair market price — only as a last resort.

The city and its consultant considered four traffic alleviation options, but recommended fixed guideway, or rail, as the preferred alternative. Other options include expanding the island's bus system, creating a toll highway viaduct, or maintaining the current bus system and continuing planned highway projects.

If the mass transit plan moves forward, councilmembers also have introduced a bill that would allow them to select what technology its vehicles would be based on: steel wheels and rails; rubber tires on a concrete guideway; monorail; or magnetic levitation.

Hannemann said such details should be left to his administration, and he said locking in one technology could prevent the city from getting the best price by forcing suppliers to compete.

"When we do funding for the buses, all they do is approve the funding. They don't tell us what kind of buses to buy," Hannemann said. "So now they want to change the game, in terms of what they want to do with rail. They want to actually dictate what the technology is. ... They're making this a whole lot more complicated than it should be."

Dela Cruz said he sponsored the bill to ensure a full public discussion about what technologies are available, but he said he does not intend to hold the project hostage for a favored type.

Hannemann said the shorter, 20-mile route can be financed through the pending half-percentage-point tax increase, along with federal assistance. But the 28-mile route will require additional money. If the council chooses that option, it must also decide how to pay for it, Hannemann said.

Gov. Linda Lingle said it was premature to discuss whether the state would still collect the increased tax if the council does not approve a transit plan by the end of the year.

However, she said, the state has been moving forward with the intent of collecting the surcharge and a system has been set up.

"It is going to be implemented," she said. "It will be ready on Jan. 1, and the money will be collected."

Lingle said she recognized the possibility that the council would not make its decision by then, but that she supports careful deliberations.

"This will be the single largest expenditure in the city's history," she said. "They will be held responsible by the public."

Reach Johnny Brannon at jbrannon@honoluluadvertiser.com.