If the city builds a rail line from Kalaeloa to Manoa, it likely would include 30 stops along the way and six new park-and-ride facilities for almost 9,000 cars, according to details of the proposal now before the City Council.

Development near the stations could range from simple, elevated, stand-alone train platforms to structures that are fully integrated into new and existing retail and residential complexes, according to city officials. They are planned for heavily urbanized places as well as currently undeveloped areas that are considered ripe for future growth, the officials said.

The size, location and design of those stations and what happens around them ultimately could determine the success of the entire rail project, according to local and Mainland transit and land-use experts.

"It's absolutely critical to the whole system," said Karl Kim, a professor of urban planning at the University of Hawai'i-Manoa. "The development around them can lead to more economic activity."

The City Council, which meets Thursday to take up transit for the second of three required readings, ultimately will decide whether to choose rail or one of several other transit alternatives, including a managed lane tollway. The council has pledged to make a decision by the end of the year.

The city estimates that between an excise tax increase scheduled to go into effect Jan. 1 and federal funding, it will have enough money to build a 20-mile, $3.6 billion line between Kapolei and Ala Moana.

However, if the council chooses to build a longer, 28-mile, $4.8 billion route, the city likely will have to rely on the sale of private development rights around the stations and other sources to make up the extra money.

City officials said they picked their proposed routes and station stops based on the need to serve existing developments and those with the potential for high-density development within a quarter-mile of the rail stop.

A $10 million alternatives analysis prepared for the city earlier this year recommends that some stations be in Kapolei Town, Leeward and Honolulu community colleges, Pearlridge and Ala Moana centers, and Ho-nolulu International Airport.

Stations planned for areas that are currently underused include Kalaeloa (the former Barbers Point Naval Air Station), the long-talked-about University of Hawai'i-West Oahu campus, Kaka'ako and a planned D.R. Horton development of up to 15,000 new homes on the 'Ewa plain.

"We looked first at areas where there is already a high density, and then at areas where a higher general density would be permitted in the future under existing plans," said Toru Hamayasu, chief engineer for the city's Department of Transportation Services.

In addition, planners tried to identify stations that could primarily serve pedestrians, bus passengers or automobile drivers, said Mark Schiebe, the planner who headed the Alternative Analysis study conducted by the consulting firm Parsons, Brinckerhoff, Quade & Douglas.

For instance, some stations like the ones along Dillingham or Kapi'olani Boulevard were specifically chosen because they are on existing bus trunk lines and near heavily traveled bus crossroads like McCully Street and University Avenue, Schiebe said.

Jim Charlier, a transit consultant based in Boulder, Colo., said building a rail station often spurs development for up to a half-mile in all directions. Those transit stations have the potential to transform low-density areas into thriving retail and residential neighborhoods, resulting in millions of dollars of new taxes for the city, an often unspoken factor in transit development, he said.

However, another transit consultant speaking in Honolulu earlier last month, warned that developments can frequently go wrong, resulting in millions of wasted taxpayer dollars.

"Just because you build something next to a rail line, it doesn't mean people will follow. In some cases, everything the planners thought would happen didn't," said John Charles, head of the Cascade Policy Institute in Portland, Ore., which is frequently cited as a model for good transit-oriented development.

Most residents near the stations don't use rail, and several publicly supported housing and commercial projects remained half-empty until city officials provided more parking spaces for automobiles, he said.

"All transit-oriented developments require subsidies. Somebody always has to end up paying for these loser projects," Charles said.

Kim, who is serving on a City Council transit advisory task force, said it's too early to talk about the types of development that will occur around new transit stations.

"We still don't know yet whether the City Council will even choose rail over the other alternatives," he said.

Mayor Mufi Hannemann, too, wants to delay speculation about transit-oriented development. Hannemann on Friday vetoed a bill that would have required the city to regulate development around each station before any budgeting of construction funds.

"The bill is premature because the City Council has yet to make a final decision on a transit mode — rail — and a route," Hannemann said.

"You have my pledge that with the timely selection of mode, presumably rail, and route, my administration is committed to developing TOD legislation," he said. "TOD legislation must involve the engagement of the community, landowners and developers, as well as coordination between government agencies."

Others fear, however, that land speculation could already be under way as the potential sites for transit stops are discussed.

"Once you make a decision on rail, you are going to be inundated with proposals from private developers. Your tax base will expand exponentially," U.S. Rep. Neil Abercrombie, D-Hawai'i, told City Council members.

Kim said once the city chooses a transit alternative, it should move quickly to put speculation safeguards in place. In some locations, that has involved increasing property taxes in transit station areas to discourage speculators from buying up nearby land.

Other municipalities have tried to control the development by buying up the land around transit stations and then selling it to developers, or create special tax districts that offer development incentives.

Charlier said that the success of transit projects depends on putting the right type of development around the stations. He suggests that design and scale of any development needs to be appropriate to the neighborhood and the type of station that is planned.

In the best ones, the developer creates a pedestrian-friendly environment around the station, hides the parking and provides a high-quality, affordable urban living lifestyle, he said.

Reach Mike Leidemann at mleidemann@honoluluadvertiser.com.