Uber's driverless cars return to public roads nine months after fatal crash

Uber said its autonomous vehicles returned to public roads on Thursday, nine months after one of its self-driving cars killed a pedestrian in Tempe, Ariz.

But Uber’s driverless vehicles are operating at drastically reduced speeds and in less challenging environments than before, the company said, as it eases back into testing and tries to ensure people’s safety.

“We will continue to prioritize safety and proactively communicate our progress until we’ve built a self-driving system that lives up to the promise of making transportation safer and more affordable for everyone,” Eric Meyhofer, who leads Uber’s autonomous vehicle unit, said in a statement.

Uber said it received permission on Monday from the Pennsylvania Department of Transportation to test its driverless cars again on public roads in Pittsburgh. The company said it planned to put fewer than five cars on the road on Thursday, and slowly add to that over time.

Each car will have two drivers inside, ready to take over in case something goes wrong, Uber said. The operators will work in four-hour shifts, down from eight to 10 hours previously. No passengers will ride in the cars.

The autonomous cars will also go no faster than 25 miles an hour, down from as fast as 55 m.p.h. before. They will operate only on a limited loop in Pittsburgh’s Strip District, a bustling commercial area, and only during daylight hours on weekdays, Uber said.

Uber said it was also putting autonomous vehicles back on the streets in Toronto and San Francisco, although those cars will operate in manual mode, which means a human driver will control the vehicles’ movements rather than software.

The company had grounded its fleet of autonomous vehicles in March after one of its cars — with an emergency backup driver behind the wheel — struck and killed Elaine Herzberg, 49, on a street in Tempe.

Getting the cars back on the road since then has been difficult. As Uber worked to make its cars safer, it lowered its expectations for speed and performance, The New York Times previously reported. Even so, the cars struggled to pass safety tests. Last month, the cars were still failing 10 out of 70 safety tests, according to internal documents.

The safety overhaul “required a lot of introspection and took some time,” Mr. Meyhofer said. “Now we are ready to move forward.”

Uber’s autonomous vehicle group will most likely face intense scrutiny over the next several months. The National Transportation Safety Board’s investigation into the fatal Arizona crash is still open.

Uber has pitched autonomous vehicles as a way to reduce the fees it pays to human drivers. But the company is still spending heavily on developing and testing the cars. Dara Khosrowshahi, Uber’s chief executive, has been focused on winnowing unprofitable businesses ahead of taking the company public next year.