Uber riders in San Francisco will be greeted with self-driving cars from today, after the etaxi giant announced an expansion of its autonomous vehicle program.

Uber has been testing self-driving cars in the wild for a while, but back in September the company opened things up to the public for the first time via a trial in Pittsburgh. Now, it’s San Francisco’s turn, with a fleet of Volvo XC90 autonomous vehicles being made available through the UberX service.

There is no specific way of requesting a self-driving car — if one’s available, you may be allocated one. And the cars aren’t completely human-free — there are operators in the back- and front-seat “monitoring” things to intervene if need be. This is a key point, considering that there has been some controversy around whether Uber actually needs a testing permit to launch in San Francisco. Naturally, Uber thinks it’s in the clear.

“We understand that there is a debate over whether or not we need a testing permit to launch self-driving Ubers in San Francisco,” explained Anthony Levandowski, head of the advanced technology group at Uber, in a blog post. “We have looked at this issue carefully, and we don’t believe we do. Before you roll your eyes and think, ‘there they go again’, let us take a moment to explain. First, we are not planning to operate any differently than in Pittsburgh, where our pilot has been running successfully for several months. Second, the rules apply to cars that can drive without someone controlling or monitoring them. For us, it’s still early days and our cars are not yet ready to drive without a person monitoring them.”

Uber has been blazing a trail in the self-driving car realm, and, alongside other technology titans such as Google, has introduced some significant advances to the autonomous vehicle realm throughout 2016. But both Uber and Google were beaten by another lesser-known company in the push to launch the first public self-driving taxi service — NuTonomy launched on Singapore roads back in August.

In many ways, it feels as though there is a rush to get to market, and Uber acknowledges that it may face some scrutiny from regulators, including the Department of Motor Vehicles (DMV) in California, which has so far issued testing permits to Google, Ford, Baidu, BMW, and myriad technology and automotive companies — but not to Uber.

“Several cities and states have recognized that complex rules and requirements could have the unintended consequence of slowing innovation,” continued Levandowski. “Pittsburgh, Arizona, Nevada, and Florida, in particular, have been leaders in this way, and by doing so have made clear that they are pro technology. Our hope is that California, our home state and a leader in much of the world’s dynamism, will take a similar view.”

By referencing “complex rules and requirements,” it seems fairly clear that Uber is aware that it could be contravening Californian regulations. But it’s going ahead and launching anyway, in traditional Uber style.

Today’s news comes a day after Google announced it was spinning out its own self-driving car division as a subsidiary called Waymo, which will now operate under Google’s parent company, Alphabet.