"Today's decision will make it harder for the people of Pittsburgh to access safe, affordable, and modern transportation options," said Lyft's Paige Thelen.
PUC spokeswoman Jennifer Kocher said investigators had issued citations since April against 23 UberX and Lyft drivers. Each could face a PUC fine of $1,000, revocation of state auto registration, and fines for traffic offenses, she said.
Kocher said the PUC judges' order "goes into effect immediately" but would be reviewed by the five-member commission. The companies have seven days to file legal objections to the rulings, based on state law governing a "situation which presents a clear and present danger to life or property."
Lyft and Uber, both privately held start-ups that have drawn capital from Silicon Valley investors, say peer-to-peer ride-sharing services offer an inexpensive alternative to taxis and limousines. Owners of those services, sometimes backed by insurance regulators and industry groups, warn that by using amateur drivers taking calls in their own cars, ride-sharing services put passengers at personal and financial risk.
Uber and Lyft won a victory in California last fall, when its utility commission created a new category of "transportation network companies" for businesses that enable drivers to offer rides dispatched via smartphone apps.
California's commission requires such services to conduct criminal checks and driver training, and offer insurance comparable to what the state requires for limo services. That accommodation draws skepticism from Alex Friedman, owner of Philadelphia's Olde City Taxi Co.
"I think the California PUC didn't realize how dangerous those operations are," Friedman said, citing a January 2013 accident by an Uber driver in San Francisco that killed a 6-year-old girl.
Uber spokesman Taylor Bennett says UberX provides "residents access to the safest, most reliable ride on the road with industry-leading safety standards and best-in-class insurance coverage."