Uber Advanced Technologies Group has resumed testing autonomous vehicles in San Francisco, two years after the company scaled back its testing program following a fatal crash in Arizona that killed a pedestrian.

Uber’s self-driving vehicle unit is tiptoeing back into testing its autonomous vehicle technology on public roads.

Uber ATG ended all testing on public roads after one of its vehicles struck and killed pedestrian Elaine Herzberg in the Phoenix suburb of Tempe. Uber ATG was testing its self-driving vehicles in the Phoenix area, Toronto, Pittsburgh and San Francisco. At the time, the company let go all 100 of its self-driving car operators in Pittsburgh and San Francisco and rumors circulated that the company wanted to sell its self-driving unit.

Uber ATG resumed in December 2018 on-road testing of its self-driving vehicles in Pittsburgh, following the Pennsylvania Department of Transportation’s decision to authorize the company to put its autonomous vehicles on public roads.

The company will initially limit testing in San Francisco to a few weeks with two Volvo XC90 vehicles equipped with Uber’s self-driving system. Testing on public roads started Tuesday and will only be conducted during daylight hours, according to Uber. Each vehicle will be staffed by a safety driver.

Uber ATG received a permit last month from the California Department of Motor Vehicles, the department that regulates autonomous vehicle testing on public roads in the state. The company said at the time that it didn’t have immediate plans to put its autonomous vehicles on public roads in San Francisco. One month later, it’s now back on the road, albeit in a limited fashion.

“We are excited to resume autonomous testing in Uber’s home city this week. Our testing area will be limited in scope to start, but we look forward to scaling up our efforts in the months ahead and learning from the difficult but informative road conditions that the Bay Area has to offer,” an Uber spokesperson said in an emailed statement.

Uber is now testing in Dallas, Pittsburgh, San Francisco and Washington D.C.