San Francisco-based Wingz, a provider of personalized and scheduled airport ride services, has begun operations at San Diego International Airport.

A company statement said the Wingz operates at major airports along the West Coast and central United States, offering frequent business and leisure travelers pre-booked, flat-rate transportation. Officials said its on-demand services are made available during off-hours and during peak-demand times, sometimes not accessible from competing providers.

Services can be booked online or through the company’s mobile application, and service rates do not change once booked.

Wingz drivers are handpicked and trained, undergoing thorough background and vehicle checks, and are provided with a $1 million liability insurance policy. Returning customers can request previous drivers, who themselves are local residents.

Officials said Wingz is backed by travel booking site operator Expedia, Altimeter Capital and CEO Marc Benioff. The company’s website indicated services were available at 15 U.S. airports as of March 22.