High-Speed Rail Backers Seek Help : Transit: Consortium appeals to county after ridership projections are cut in half. Line is to run from LAX to Palmdale.

The consortium proposing to build a high-speed rail line between Los Angeles International Airport and Palmdale, a $1-billion project that was to be privately financed, Monday asked for financial support from the county because ridership estimates have been reduced by almost half.

In response to a request from the consortium, a panel of the Los Angeles County Transportation Commission on Monday recommended consideration of public funding for the proposed 69-mile line. One county official said the potential bill could reach $100 million a year.

The turnabout came after the project’s backers reduced ridership projections for the line’s first segment--the 36 miles from Los Angeles Airport to Santa Clarita--from 100,000 riders a day to about 55,000, with a corresponding drop in expected revenues, county officials said.

John E. Chiaverini, a spokesman for the consortium, acknowledged the reduction in ridership estimates, although he could not confirm the precise numbers.

The consortium apparently had earlier overestimated the number of bus riders who might make connections with the train, said Linda Bohlinger, director of capital planning and programming for the commission.

The transportation panel’s meeting Monday produced the first public indication that the proposed rail line--which would use futuristic magnetic levitation technology to reach speeds up to 100 m.p.h--might not be entirely privately financed. Its backers are seeking approval for the project under an experimental state privatization program for transit projects.

However, consortium and county officials said the project could still go forward with local public funding, because the state requires only that no state or federal funds be used. State officials in mid-September are to choose up to four such projects out of eight submitted statewide.

Bohlinger said county officials are willing to consider local funding. Based on preliminary projections, the public’s obligation could approach $100 million a year for up to 15 years, she said.

Bohlinger said the consortium’s own projections showed that public funding could amount to one-third to one-half of the line’s total operating and construction costs for the first 15 years. Only at that point, she said, was the line projected to become self-supporting.

“The commission and our executive director want to portray the message that we’re looking at this very positively,” Bohlinger said. “They’re not dismissing this out of hand. They’re willing to look at the possibility of the commission being financially involved.”

The commission’s Finance and Programming Committee voted 5 to 0 Monday to explore public funding options, including possible contributions from the commission, the city of Los Angeles and the city’s Department of Airports.