Uber today restarted tests of its self-driving cars in Pittsburgh, eight months after one of its prototypical Volvo SUVs struck and killed a pedestrian in Tempe, Arizona. Uber received a letter earlier this week from Pennsylvania’s Department of Transportation authorizing it to redeploy its fleet in the city. And Eric Meyhofer, head of the company’s Advanced Technologies Group (the division responsible for the bulk of Uber’s driverless car research) said in a blog post this morning that manual tests had relaunched in San Francisco and in Toronto.

“Manual driving introduces new scenarios that our system will encounter and allows us to recreate them in a virtual world or on the test track to improve system performance,” Meyhofer wrote. “This is an important step to self-driving operations. We will only pursue a return to the road for self-driving in these cities in coordination with federal, state, and local authorities.”

The Pittsburgh redeployment won’t be close to full scale. Uber’s cars will operate on a mile-long route between two of its offices in the city’s Strip District and will travel no faster than 25 miles per hour, the company said. They will also stay off of the roads at night and during inclement weather. Moreover, the vehicles will be driven by teams of two employees — “mission specialists” — who will switch off every two hours and who will both be limited to four hours behind the wheel in a workday.

A spokesperson for Pittsburgh mayor Bill Peduto told the Verge that Uber has “accepted established state guidelines, demonstrated transparency, and conformed to our expectations in addressing the unique conditions of a complex urban environment” and that its autonomous cars “will not introduce an increased level of safety risk in Pittsburgh.”

Uber started reintroducing fleets of self-driving cars in Pittsburgh late this summer, albeit with their autonomous systems disabled. In a blog post published in June, Meyhofer detailed other newly implemented safeguards, such as a training program focused on safe manual driving and monitoring systems that alert remote monitors if drivers take their eyes off the road.

Uber says that it has spent months testing its self-driving technology on a closed track and that it has completed a lengthy internal review. It has also hired an advisor — former National Transportation Safety Board (NTSB) chair Christopher Hart — to assess the company’s safety culture.

Following the March crash, Uber halted self-driving tests in San Francisco, Toronto, and Pittsburgh, shortly after Arizona governor Doug Ducey suspended the company’s permission to deploy cars in the state. More recently, Uber laid off 100 of its autonomous vehicle operators, although it has encouraged them to apply for new jobs in Pittsburgh.

This summer, the NTSB determined that Uber had disabled the automatic emergency braking system in the Volvo XC90 involved in May’s fatal crash. (In internal documents, the company said this was to “reduce the potential for erratic vehicle behavior.”) The NTSB also found that the car’s perception system detected the victim about six seconds before impact but that it didn’t determine emergency braking was needed until 1.3 seconds before impact.

According to a separate report from the Informationa former Uber manager raised concerns about the driverless cars’ road-readiness in an email sent days before the accident

In a voluntary safety assessment filed with the National Highway Traffic Safety Administration, Uber said that with a newly established systems engineering testing team it’s now better positioned “to reason over many possible outcomes to ultimately come to a safe response,” and that in the coming months it will form a self-driving safety advisory board of outside experts.

“At Uber, we believe that technology has the power to make transportation more efficient, accessible, and safer than ever before,” Meyhofer wrote. “Self-driving technology has the potential to make these benefits an everyday reality for our customers, but it’s not going to happen overnight. Building best-in-class self-driving technology will take time, and safety is our priority every step of the way.”