California's high-speed rail project has a tight schedule to keep: It must meet a series of deadlines to keep $2.5 billion in federal money. But some experts say the program already is running late.

Construction of the system is supposed to start in late 2012 or early 2013 and be completed in 2017.

But no detailed environmental reviews have been finished, no property has been acquired and no construction contracts have been awarded.

All of that has to happen before dirt can begin to fly on the first section to be built between Fresno and Bakersfield.

"In my heart of hearts, I don't think the expectations are realistic," said James Moore II, director of the Transportation Engineering program at the University of Southern California. "There will be delays."

Those delays not only would threaten the funding -- they also would postpone the expected bonanza of construction jobs for the Valley well past next year, experts say.

The size and scope of the high-speed rail project's first segment make it perhaps the largest infrastructure effort in the Valley's history. And the clock is ticking.

The California High-Speed Rail Authority's grant agreement with the Federal Railroad Administration requires that environmental studies be completed and certified by September for sections from Merced to Bakersfield.

For the first section to be built between Fresno and Bakersfield, contracts for final engineering and construction must be awarded by September 2012, and construction must be finished by September 2017.

The section would be the initial piece in what is ultimately planned as an 800-mile system linking the state's urban centers with trains capable of speeds up to 220 mph. Service is not likely to begin until 2020 or later, after the system has grown to link Los Angeles and San Francisco.

Even the California High-Speed Rail Authority acknowledges the challenging time frame. "It's certainly optimistic, and it's very tight," said Rachel Wall, the authority's press secretary.

But authority managers say it's a realistic schedule because so much study and analysis already has been done, accelerating after voters approved Proposition 1A in November 2008 to provide $9 billion for high-speed rail.

"We think these Valley sections are well enough along that this is a doable time frame," said Jeff Barker, the authority's deputy executive director.

"We've got some things going on simultaneously, and even giving ourselves some time for delays, we're real comfortable with the time frame."

The federal money is intended to stimulate the economy quickly in the Valley and the state.

But for government bureaucracies that sometimes move at a glacial pace, "quickly" is a relative term -- and that is what worries observers.

Detailed planning

The construction itself would be a formidable task. But there is much to do even before the first shovel pierces the ground.

The first hard deadline for the federal funds involves environmental-impact reports, or EIRs, detailing the potential effects of the train system on Valley communities, farms and wildlands. Final versions of those reports must be certified by the end of September.

Consultants have been working on the Valley EIRs for more than a year, and the authority plans to issue drafts in February for 45 days of public comment and debate.

That is about two months later than what the authority set as its target last year. Consultants will then make revisions or come up with responses based on those comments, before final versions are opened for public comment.