Cruise has slowly been allowing members of the public to ride in one of its driverless taxis on the streets of San Francisco since February, but until now the company hasn't been able to charge a fare.

The self-driving technology startup, whose main shareholder is General Motors, last week was granted permission by the California Public Utilities Commission to start charging a fare for its rides. Anyone looking to take a ride in one of Cruise's driverless taxis still needs to sign up on the company's website and await an invitation.

Commercializing its service is a major milestone for the company which was founded in 2013. However, getting to the point where there will be a large fleet of Cruise driverless taxis zipping around San Francisco will take some time.

Cruise currently has permission to operate 52 of the so-called robotaxis in the city, but only between 10 pm and 6 am, when the streets are mostly empty. The vehicles are limited to 30 mph and cover only certain parts of the city, skipping busy areas like the Market Street business corridor, though this is expected to be expanded within months.

Cruise's vehicles rank at Level 4 on the SAE scale of self-driving capability, as they are limited in areas in which they can operate. The final goal is Level 5, where a driverless car is able to operate at the same level as a human driver. While Level 5 might be a decade or more away, companies are already offering commercial services involving Level 4 cars. Alphabet's Waymo One service has been up and running in parts of Phoenix, Arizona, for the past three years, and China's Baidu launched its Apollo Go service in Beijing last year.

Cruise's driverless taxis are based on the Chevrolet Bolt EV. Eventually, Cruise will switch to using its own shuttle vehicle known as the Origin, the design of which was first shown in early 2020. In addition to transporting passengers, Cruise is looking at delivery of goods. The company is working closely with retail giant Walmart, one of its investors, to trial a delivery service.