The San Francisco city attorney has sued online car-sharing company Turo, claiming it flouts rules designed to prevent congestion around San Francisco International Airport and provide funding for airport infrastructure.

The complaint filed in San Francisco Superior Court Wednesday claims Turo, formerly known as RelayRides Inc., has continued to provide customers with airport rentals via its website even though its permit to provide “off-site” rental car services at SFO expired last summer. The city contends Turo allows people who rent through its site to have vehicles delivered curbside at SFO's terminals—skirting rules designed to filter rental car customers to designated areas away from the terminals via the airport's AirTrain light rail system.

The airport charges an $18 per ride fee to rental companies for the AirTrain service and received roughly 11.5 percent of its annual operating budget from fees paid by rental car companies last year, according to the complaint.