The last time the city studied the viability of a ground-level train through Honolulu's urban core, there was no medical school or Kaka'ako Walmart and several high-rise luxury condominiums had yet to be built.

The 1998 study, along with another conducted in the early 1980s, also preceded the widespread adoption of accessible low-floor light rail vehicles and train power systems that don't require overhead wires.

City officials say those studies prove that an entirely elevated $5.5 billion commuter rail is Honolulu's best option. However, proponents of a ground-level train in urban Honolulu argue that those earlier studies are outdated and inadequate.

"A lot has changed" since those studies were conducted, said Jeff Nishi, president of the American Institute of Architects Hawai'i's Honolulu chapter.

The AIA, Kamehameha Schools and others contend a rail system built at least partially at grade would cost less and have less visual impact. The city maintains that a ground-level train would operate at slower speeds and generate lower ridership and higher long-term costs.

Just how much a partially at-grade train would cost and how many people it would carry is unclear. That's because the city eliminated an at-grade light rail system from consideration before conducting a key environmental impact study released this spring. Instead, the options explored by the city included an all-elevated train, managed highways and an expanded bus system.

The last time the city studied the feasibility of an at-grade train was in 1998. That study found that a ground-level train running through Honolulu's urban core was feasible. However, the copy of the study provided by the city to The Advertiser under a Freedom of Information request did not include cost or ridership estimates, nor did it compare the performance of an at-grade train against any other transit alternatives.

The 1998 study found that Hotel Street would be a good at-grade transit path through Downtown because that street already is dedicated to buses. However, a Downtown-to-University of Hawai'i route via King Street would likely reduce traffic flow, according to the study. The report did not study the feasibility of an at-grade train route down Halekauwila Street. Current plans call for an elevated train that runs down Halekauwila.

Before 1998, the last time an at-grade rail was studied in-depth was in 1982, according to the city. That study found that a partially at-grade light rail system was slightly inferior to an entirely elevated train.

WIRES WERE CONCERN

The study recommended the city build a more expensive fixed-guideway train system that would operate at faster speeds and generate higher ridership than a partially at-grade light rail system. At the time, part of the concern about light rail was the negative aesthetics of overhead catenary wires.

The city did not follow through with plans to build a train system in the 1980s or 1990s. However, plans to build a train were kick-started after Mayor Mufi Hannemann took office in 2005.

City Council member Gary Okino said findings from studies conducted during the 1980s and 1990s remain valid today. If anything, an increase in traffic congestion since the 1980s makes at-grade rail even less attractive today, Okino said.

Because an elevated train operates on an exclusive right of way, it can operate at higher speeds and generate higher ridership . In contrast, a cheaper-to-build at-grade train would generate lower ridership while increasing traffic congestion, Okino said.

"There's a tremendous difference in terms of costs, efficiency, speed, capacity, everything," he said. "I don't care what kind of studies you do, or how technology has changed. There's no comparison between an elevated and an at-grade system."

The most recent study of an at-grade Honolulu rail system was conducted this spring by New Jersey transportation consultant Phil Craig for the Kamehameha Schools. Honolulu could save an estimated $1.7 billion by building about half of its planned elevated commuter train system at ground level, according to the study.

Craig proposed building the train system at ground level from East Kapolei to Waipahu and from Middle Street to Ala Moana Center. Only the segment from Waipahu to Middle Street, or about 10 out of a total 20 miles, would be built on an elevated guideway.

Because it would mix with automobile traffic, the proposed at-grade train would operate at slower speeds than an entirely elevated train. However, the Craig study proposed an alternative route that could place more Downtown commuters closer to their destination. The current route of the planned elevated train travels the periphery of Downtown by running along Nimitz Highway to Halekauwila Street, then Kapi'olani Boulevard.

Craig proposed a route that would enter Downtown via North King Street to Hotel Street, then makai on Richards Street to South King Street or Queen Street. Heading 'ewa, the ground-level train would travel from Kapi'olani Boulevard to South Street, then South Beretania Street to Richards Street, then reconnect at Hotel Street.

NEW TECHNOLOGY

Modern train technology that doesn't require overhead power lines would allow at-grade trains to travel primarily along curbside lanes now used by buses, Craig said. Before such technology became available, a light rail system in Honolulu would have needed to use lanes in the middle of the street. That would be more detrimental to traffic than running in curb lanes, which already are heavily used by buses, Craig said.

"Ten years ago they were not able to use the curb lanes for light rail because of the tree cover along Kapi'olani as well as Dillingham," he said. "With wireless technology you can run in those lanes just as TheBus does."

Money saved building an at-grade train could be used to build extensions of the East Kapolei to Ala Moana train into areas such as Waikíkí and the University of Hawai'i-Mänoa. A reduction in the cost of the rail project could help the city deal with shortfalls in tax collections needed to pay the city's $4 billion share of the project.

LACK OF FULL STUDY

However, the city says a more expensive, all-elevated train would be safer and have a greater maximum passenger capacity than a ground-level train. An at-grade train also would reduce the availability of road lanes, which would create greater traffic problems and increase commuting times, according to the city.

Craig said the city has not conducted any recent studies to support those contentions. City transportation Director Wayne Yoshioka was unavailable to comment for this story.

The lack of a more recent city study of an at-grade train has raised questions about whether that option was adequately studied.

"I think it's been insufficient," said Nishi, of the architects institute. "They're going in one direction, that's obvious. It doesn't benefit the community."

The city's decision to eliminate at-grade rail options without studying the costs, benefits and environmental impacts could present problems should opponents try to stop the project via a lawsuit, Craig and others have said.

City Council members Charles Djou and the late Duke Bainum wrote the U.S. Department of Transportation in June stating that the city should have studied other transit alternatives as well as alternate routes.

The concern is that it's impossible to judge whether the current elevated rail and the route are the most environmentally favorable options unless alternatives are fully studied.

"There has to be a common level — basically an even playing field between the (different) modes up to the point where you determine which ones are more desirable in terms of the capital investment required versus the number of passengers carried and their effects on the environment," Craig said. "The proper procedure is you choose your recommended alternative after you have explored the options at the (draft environmental impact study) level."

City Council member Okino said the superior performance and environmental benefits of elevated rail are obvious and don't require further study.

"We could have presented a whole bunch of information that would have shown it very clearly, but that's hindsight," Okino said. "Even if that's challenged, we can show existing data and studies that show clearly that there's no comparison, even if it's not Honolulu.

"It's an easy thing to prove."