PITTSBURGH (AP) — Uber has taken the first step toward relaunching its self-driving cars on Pittsburgh-area streets four months after a fatal accident involving one of the cars in Arizona.
A spokeswoman said the company put a handful of vehicles back on the road at noon Tuesday, with some safety modifications to the cars and driver training. But for now, the cars won’t be free of human control or respond to ride-hailing calls.

A car in autonomous mode is operated or driven without active physical control by a person sitting in the driver’s seat, while a driver operating in manual mode has the ability to brake, turn the steering wheel or control other operations.
“Building best-in-class self-driving technology will take time, and safety is our priority every step of the way,” Eric Meyhofer, head of Uber Advanced Technologies Group, wrote in a blog entry posted to Medium.com Tuesday.
Meyhofer outlined some of the changes that have been made to the cars since the fatal accident in Tempe, Arizona, in March.
Elaine Herzberg was struck and killed by a self-driving car as she crossed a darkened road outside of the crosswalk. A 300-page investigative report by the National Transportation and Safety Board showed the driver had been streaming a television show for more than 40 minutes before the accident while the car was in autonomous mode.
Uber halted the program in all of its test markets to launch a safety review of the cars and training. The cars for now are not being reintroduced in the other test markets including San Francisco and Toronto.
Meyhofer said the cars will now have driver-monitoring systems that alert a remote monitor if the drivers are not being attentive. Uber’s collision avoidance system, which was already built into the cars, will now remain enabled during manual driving.

The company also increased driver training at its test track near Pittsburgh. And Meyhofer said the Pittsburgh roll-out will help the company make further adjustments by creating real-life scenarios for driver training. The company would not specify how many cars are being put on the streets in the rollout.