Austin has Lyft-off without clearance.

Transportation network companies, or TNCs, may not yet be legal by city ordinance, but that has not stopped TNCs such as Uber and Lyft from launching in Austin.

The two taxi alternatives began offering service in late May despite an Austin Police Department sting operation that left three Lyft drivers with citations and two Lyft vehicles impounded. Lyft officials claim their smartphone application has been downloaded locally more than 15,000 times, and an online petition shows more than 20,000 signatures in support for Uber.

However, support for these ridesharing options is not universal. Austin Yellow Cab President Ed Kargbo said safety is a big concern when comparing TNCs to traditional taxi service.

Lyft and Uber do not share driver information such as insurance policies and background checks with the city because they argue they should not be held to the same requirements as taxi cabs, Kargbo said.

"They claim they're not cab companies," Kargbo said. "They do everything a cab company does, though."

A city pilot program to explore regulations for TNCs has not yet been completed. Despite that program still being in its early stages, representatives from the ridesharing companies insist their internal safety standards are adequate.

"Lyft's safety measures are actually far more rigorous than those of Austin taxis," Lyft spokeswoman Kate Dally said.

Lyft and Uber both promise a $1 million insurance claim per accident occurrence. This claim only kicks in if the driver's existing insurance plan cannot cover damages or if the driver's insurance "doesn't respond," according to Lyft's website.

Kargbo said these promises are unsubstantiated because passengers are supposed to deal with the driver's insurance company.

"They shift the burden," he said. "They make a lot of promises with zero proof."