The railroad may be making a comeback on O'ahu.

A panel of city-appointed experts yesterday decided that traditional steel wheels and rail technology is best suited for Honolulu's planned $3.7 billion elevated commuter line.

The decision was based on factors such as reliability, safety, ride quality and cost, according to the four city-appointed panel members who voted in favor of steel rail technology for the 20-mile route between Kapolei and Ala Moana Center. Rubber tires on concrete technology came in a distant second, garnering only one of five votes. Both magnetic levitation and monorail technologies were ruled out because of cost and capacity concerns.

Steel wheels on steel rails generate less friction than rubber on concrete and last longer, but they typically have lower acceleration and braking performance than rubber on concrete. Steel also is noisier than other rail technology.

Panel member Ron Tober downplayed concerns raised about the noise and vibration of steel railway systems.

"The new vehicles, the new technology is in fact very quiet and they can be made to be nearly vibration-free," Tober said. "Some of the other technologies I don't think are proven enough for Honolulu to take the risk."

The decision could mark the return to O'ahu of railroad technology, which disappeared from much of the island's landscape in the mid-20th century.

A decision on the type of vehicle must be made before an environmental impact statement for the project can be completed and the city can apply for federal transit money. Mayor Mufi Hannemann hopes to break ground on the project in 2009, with the first segment starting service between East Kapolei and Waipahu in 2012.

In addition to being a proven technology, the decision to go with steel rail opens the project to at least five potential vehicle vendors, which was greater than any of the other alternatives, said panel member Henry Kolesar.

"It's most competitive if we select something that's widely available," he said. "Sticking with the low-risk proven technology is in the best interest of Honolulu."

So far, the vendors proposing using steel wheels on steel rails for Honolulu's transit system are ALSTOM Transport, AnsaldoBreda Transportation Inc., Bombardier Transportation, Mitsubishi-Sumitomo and Siemens Transportation Systems Inc. They are vying for a future vehicle contract from the city valued at an estimated $230 million.

Panos Prevedouros was the only panel member to recommend the city choose rubber on cement technology for the project. Prevedouros, a rail opponent, also recommended the city switch from a fixed-guideway rail-transit solution to a guideway with ramps and managed lanes.

Prevedouros said fast, high-capacity "super buses" would be cheaper to install and allow more future flexibility than rail.

A fixed railway system requires commuters to ride TheBus to the train, which will result in low ridership and won't reduce congestion, said Prevedouros, who is a University of Hawai'i transportation engineering professor.

"People are fed up with 75 to 90 minute commutes," he said. "They are sitting in their car and they're looking for a solution. But they're looking for the other guy to take the train and (in other cities), the other guy is not taking the train."

The panel's choice isn't the final decision in the matter. However, it is expected to tilt the debate in favor of steel rail.

The City Council's Committee on Transportation and Public Works is scheduled to hold a hearing on the panel's selection Thursday. Council members Ann Kobayashi, Donovan Dela Cruz, Romy Cachola and Charles Djou yesterday asked the committee to consider a last-minute proposal that would let the council specify the criteria that will be used to solicit bids for transit vendors. That would likely leave open the question of which technology to use.

An official bid solicitation won't be made for at least a year.

City Councilman Todd Apo said he hoped the panel's decision would end the debate over whether the planned elevated guideway project will be a rail, rather than a managed lane system.

"For our city's mass-transit project, I think the technical experts are telling us that (from) the practical realities of it, it needs to be a rail system," he said.

Reach Sean Hao at shao@honoluluadvertiser.com.