CITY Councilman Duke Bainum has questioned the city's choice of an elevated rail system for the transit line from Kapolei to Ala Moana, but similar arguments made during Bainum's absence from Hawaii were rejected more than a year ago with good reason. The city has rightly rejected his protest as late and inaccurate.

In a commentary column in the Star-Bulletin Monday, Bainum maintained that the city will spend more than twice as much for an elevated rail system than it would cost for a rail system at street level that could be built in less than half the time of the nine years projected for construction of the elevated rail. Those arguments were made by a group of local architects in December 2007 and were rejected.

Mayor Mufi Hannemann had explained in a letter to the Honolulu chapter of the American Institute of Architects why the proposed street-level rail would be impractical, and why the architects' estimate of construction costs failed to consider various factors. Wayne Yoshioka, director of the city Department of Transportation Services, reiterated those reasons in a column published Thursday.

Yoshioka explained that street-level trains take up to three traffic lanes, and that would create havoc in urban areas such as Kalihi, Kakaako, Ala Moana and downtown by contributing to traffic congestion. He added that elevated trains go 50 percent faster than trains at street level, which travel at about the same speed as buses.

Bainum suggested the cost of the street-level system would be $2.5 billion, compared with at least $5.3 billion for the elevated rail. That might be true if the street-level system were to be built on existing or abandoned rail corridors or other rights-of-way, as in other cities where it has been built, Yoshioka responded.

Otherwise, the city would have to buy property to create the right-of-way.

In the Seattle area, that meant displacing nearly 300 businesses and homes along a five-mile stretch to create the right-of-way, Yoshioka pointed out. Honolulu's guideway would require fewer than 40 property acquisitions.

A five-expert panel chose the technology for the rail system in February 2008 with one dissent — University of Hawaii engineering professor Panos Prevedouros, who pushed for a rubber-tired bus system and then unsuccessfully challenged Hannemann's mayoral re-election. The City Council gave its approval of the steel rail system.

Bainum, who was defeated by Hannemann in the 2004 election, suggests that what he regards as the Hannemann administration's failure to consider his favorite system may create “;a Superferry-like legal limbo.”; The fact that Bainum was absent from the islands when the city went forward with environmental studies required by law should not put the system in jeopardy.