O'ahu should expect rising property values, economic growth and lots of new development to accompany the mass transit system planned for the island, according to transportation leaders who will address such issues in a city-sponsored symposium today.

The planned route linking West Kapolei to Downtown Honolulu and communities farther east "is well known as one of the best, if not the best, undeveloped transit corridors in the nation," said Michael Townes, chairman of the American Public Transportation Association.

More than a dozen transportation and planning officials from the Mainland and Canada are scheduled to address about 350 developers, contractors and others who mainly support the controversial $5 billion project — and are paying $45 each to attend the daylong event at the Blaisdell Exhibition Hall. Mayor Mufi Hannemann also will make a presentation.

O'ahu "would be missing a major opportunity for economic development if you don't do light rail," said Townes, who also is CEO of the transit authority of Hampton Roads, Va.

It's important to remember that major public transit systems are meant to guide and support new development and decades of anticipated population growth, he said.

"You don't plan transit for today's demands; you project out into the future," Townes said. "Honolulu is going to grow. Moving around is not easy here. Think about what it will be like if there are half a million or three-fourths of a million more people."

The financial cost of building new transit systems must be weighed alongside such costs as time lost sitting in traffic, poor air quality and limited mobility, said Nathaniel Ford, executive director of the San Francisco Municipal Transportation Agency.

"That's not always clearly evident when you talk about these kinds of projects," Ford said. "Most successful cities have good transportation infrastructure."

A new light rail line from downtown San Francisco to its southeast corner has quickly increased property values there and helped spur new development in areas that had been bleak and run down, he said.

In the city's South of Market district, a major new residential and commercial building — to be the tallest U.S. structure west of the Mississippi — is expected to pay for a new Transbay Terminal included in the project, Ford said.

The terminal will link several transit systems and transportation modes, and is an example of how new development can help pay for transit infrastructure, he said.

San Francisco has long had a complex and heavily used public transit system that includes light rail lines, buses and cable cars. Traffic jams remain a problem there, however.

"With congestion, our system is slowing down," Ford said. "The average speed of our buses is below 10 miles per hour."

Providing exclusive paths for mass transit vehicles is one of the best ways to solve such problems, he said.

San Francisco is considering that option for new transit lines planned along Van Ness Avenue and Geary Boulevard, two of the city's major transportation corridors, Ford said.

Reach Johnny Brannon at jbrannon@honoluluadvertiser.com.