(NewsNation) — Cruise’s self-driving vehicles will start being tested in Nashville, Tennessee, on Friday, the company announced on Twitter.

“Today we are announcing Nashville as our next robotaxi-enabled city!” Cruise CEO Kyle Vogt said Thursday. “You’ll see driverless @cruise AVs there in a few months.”

According to Vogt, that means Cruise will be available in seven cities. Just one year ago, it only operated in San Francisco, California.

More cities Cruise is planning to expand to will be announced soon, the company said.

However, although it has tested vehicles in multiple cities already, Cruise is only commercially operating them in San Francisco, Austin and Phoenix.

To roll its vehicles out Cruise has developed a system, TechCrunch writes, where it enters a new market with test vehicles that eventually lose its “human safety operator.” Then, access to the vehicles is given first to employees, and then customers, who signed up for Cruise, with a limited service area and hours that end up expanding, TechCrunch reports.

“Each time we add a new city, the performance in our current cities keeps getting better. We’ve got a playbook running now,” Vogt said on Twitter. “Scout a city, augment our datasets, retrain, validate, and go. Once we’re up and running, the data keeps streaming in.”

Currently, Cruise is working on expanding its commercial operations in San Francisco — although officials, according to the Los Angeles Times, are skeptical of the driverless cars, saying they block traffic and emergency vehicles.

“They’re not ready for prime time,” San Francisco Fire Chief Jeanine Nicholson said, according to the newspaper.

In a statement to NewsNation, Cruise spokesperson Hannah Lindow said the company is proud of its safety record.

“We’ve received overwhelmingly supportive comments as we have sought to expand our service  –– including from accessibility advocates, small businesses and local community groups,” Lindow said.