California taxicab companies can sue competitor Uber over advertising statements that it offers the safest rides on the road, a federal judge has ruled.

The suit was filed in March by 19 taxi companies in several cities, including San Francisco. They accused the ride-hailing company of false advertising for stating in ads and online postings that its background checks were the most thorough and its services the safest in the business. The statements implied, and sometimes explicitly declared, that conventional taxis were less safe.

In fact, the taxi companies said, their review of prospective drivers is far more thorough. They said they use fingerprint checks and government criminal records that Uber does not employ and require their drivers to take a driver safety course and a written exam. Without discussing the merits of those claims, U.S. District Judge Jon Tigar of San Francisco on Friday rejected Uber’s attempt to dismiss the suit Friday and said much of it could proceed.

Some of the Uber statements challenged by the cab companies were mere “puffery” that make no factual assertions and can’t be challenged under false-advertising laws, Tigar said. He cited ads that said Uber is “going the distance to put people first” and has “background checks you can trust.” He also said some of Uber’s statements were made to journalists and printed only in news media, and were therefore constitutionally protected.

But other comments in ads or on the company’s website could lead a “reasonable consumer“ to “conclude that an Uber ride is objectively and measurably safer than a ride provided by a taxi,” Tigar said.

He cited Uber’s claims that its safety standards are “already best in class” and “industry-leading.” A statement on Uber’s blog asserted, “Unlike the taxi industry, our background checking process and standards are consistent across the United States and often more rigorous than what is required to become a taxi driver.”

Tigar said the taxi companies can’t seek damages for fraud, because they weren’t defrauded by any allegedly false advertising. But a federal false-advertising law, the Lanham Act, allows competitors who are harmed by misleading ads to seek damages for their own resulting losses and the other company’s profits from any improper practices.

Benjamin Shiftan, a lawyer for the cab companies, said the ruling allows the heart of the case to continue.

But Uber officials saw the decision as a plus.

“We’re pleased that the court dismissed a substantial portion of the claims, and we continue to believe that the remainder of the lawsuit lacks merit,” said a spokeswoman for the company.

Bob Egelko is a San Francisco Chronicle staff writer. E-mail: begelko@sfchronicle.com Twitter: @egelko