Uber has been doing an extensive review of the self-driving vehicle program since the Tempe pedestrian was struck and killed as she crossed the street. Investigators later said the sole vehicle operator, whose job was to be a fail-safe for when the cars act erratically, was streaming a television show on her phone, contributing to the accident. Self-driving vehicle experts have questioned the effectiveness of Uber's technology and its move in late 2017 to stop using a second safety driver that it had previously stationed in the front passenger seat of its autonomous test cars. The company had disabled an automatic emergency braking system on the Volvo involved in the crash, which put added responsibility on the operator to stop or swerve the vehicle in the case of an obstacle, according to a report from federal investigators last month. Many technologists view self-driving vehicles as the future of transportation because they eliminate human error, thereby reducing costs from crashes and liability insurance.