California's $68 billion bullet train is supposed to travel from San Francisco to Los Angeles in less than two hours and 40 minutes.

That speed - an average of more than 140 mph, including stops - is a legal requirement, written into a 2008 state voter initiative.

Boosters continued to promise that the train would attain those speeds even after Gov. Jerry Brown cut $30 billion from the project's budget this year, forcing a reconfiguration that seemed likely to slow down the train.

But, according to a lawsuit filed by project opponents, the state High-Speed Rail Authority has not done any studies to verify that the trains actually will go fast enough to follow the law. The suit, filed by the Kings County Board of Supervisors, quotes a May 31 e-mail from a project official as saying that "no document exists" to verify that the train can meet its travel time deadline.

The rail authority's promises are backed up by "verbal assertions based on (the) skill, experience and optimism" of project engineers, according to what the rail official wrote in response to a request for public information.

That statement "casts great doubt on the credibility" of the assertions the authority is making about the bullet train, Kings County says in the lawsuit, which seeks a court order to cut off state funding for the project. The county says constructing the rail line also will wreck thousands of acres of prime Central Valley farmland.

Project defended

In a statement, rail authority Chairman Dan Richard said the reconfigured project will comply with the law.

The state attorney general's office has asked a Sacramento judge to dismiss the lawsuit, arguing that opponents have presented no evidence that the rail authority is making illegal expenditures on the project. A hearing is set for Friday.

Last year, judges tossed two similar lawsuits that sought to have the project stopped on the grounds of illegal or wasteful spending.

In April, when the governor slashed the project's $98 billion construction budget, the rail authority introduced the rail network plan in which high-speed trains would share tracks with Caltrain on the Peninsula and with Amtrak and Metrolink in the Los Angeles Basin.

Some rail experts, including advocates of the California project, questioned how bullet train speeds could be maintained.

"All over the state ... they're going to use commuter trains, Caltrain, light rail in Stockton," Kings County attorney Michael Brady said. "You're not going to be able to get from Los Angeles to San Francisco in six hours."

That would violate state law. Many experts say it would also doom the project because slow trains would persuade most passengers to buy a plane ticket instead.

Documents requested

Richard has been emphatic that the train will achieve the speeds the law requires. In a presentation in April in Fresno, he said: "Our engineers have told us it will achieve the performance standards the voters insisted on in the ballot measure. And so that means trains that can go from Los Angeles Union Station to the Transbay Terminal in San Francisco in two hours, 40 minutes."

Kathy Hamilton of the Community Coalition on High Speed Rail, a Peninsula group that opposes the project, filed a Public Records Act request for the data Richard used to insist the rail project will meet its time objectives.

There wasn't any, she was told.

In an e-mail, rail official Kyle Wunderli wrote: "I have an answer on your request for some documented proof of the assertions the engineers made to Dan Richard. The answer is that no document exists. These were verbal assertions based on skill, experience, and optimism and so Dan Richard went with the expertise of the engineers offering these assertions."

Train speeds are among the most important aspects of the project, Brady said. It "makes them look ridiculous" to base their claims about train speeds on engineers' optimism, he said.

Brady said he suspected that there is no written material on the topic because it's simply not possible for the reconfigured train to go fast enough to comply with the law. It would be illegal for the state to spend money on the project if that's the case, he said.