https://phys.org/news/2018-12-uber-resumes-autonomous-vehicle-pittsburgh.html > The ride-hailing company received permission to resume testing from the Pennsylvania Transportation Department on Monday. It plans to start with a few cars in an area near its offices. > Uber has pledged to have two human backup drivers and take other safety precautions in each Volvo SUV. It also will stay in an area where speed limits on most roads are 25 mph.