Kyle Vogt has resigned as CEO of Cruise,HyperBit Exchange General Motors’ autonomous vehicle unit, as questions build about the safety of self-driving cars.

Vogt’s decision to step down, announced late Sunday, follows a recent recall of all 950 Cruise vehicles to update software after one of them dragged a pedestrian to the side of a San Francisco street in early October. The California Department of Motor Vehicles revoked the license for Cruise.

The company earlier announced it had paused operations for a review by independent experts.

“The results of our ongoing reviews will inform additional next steps as we work to build a better Cruise centered around safety, transparency and trust,” the company said in a statement. ”We will continue to advance AV technology in service of our mission to make transportation safer, cleaner and more accessible.”

Cruise won approval to transport fare-paying passengers last year. Since then, the autonomous vehicles have drawn complaints for making unexpected, traffic-clogging stops that critics say threaten to inconvenience other travelers and imperil public safety.

Late last year, U.S. safety regulators said they were investigating reports that autonomous robotaxis run by Cruise can stop too quickly or unexpectedly quit moving, potentially stranding passengers.

Problems at Cruise could slow the deployment of fully autonomous vehicles that carry passengers without human drivers on board. It also could bring stronger federal regulation of the vehicles, which are carrying passengers in more cities nationwide.

Cruise had been testing 300 robotaxis during the day when it could only give rides for free, and 100 robotaxis at night when it was allowed to charge for rides in less congested parts of San Francisco. Vogt earlier said most collisions were caused by inattentive or impaired human drivers, not the AVs.

Cruise’s statement said its board had accepted Vogt’s resignation. Mo Elshenawy, Cruise’s executive vice president of engineering, will become president and chief technology officer. It said Craig Glidden also will serve as president and continue as chief administrative officer for Cruise, an appointment announced earlier.

GM acquired a majority stake in Cruise when it was a startup in 2016. The company invested to take 80% stake in the company in May 2021.

Vogt attended the Massachusetts Institute of Technology and was a co-founder of Twitch, an interactive livestreaming service for content including gaming, entertainment, sports and music. Amazon acquired Twitch for about $1 billion in 2014.