It’s reported that Google’s driverless vehicle devision, Waymo, has put so-called “safety drivers” back behind the wheel of its most advanced driverless prototype vehicles.

The website The Information says this ends a year-long period in which those people generally sat in the passenger seat or in the back.

The report adds that this is despite the company having only weeks to meet its self-imposed deadline to launch a public taxi service using fully automated cars by the end of 2018. “Right now,” it says, “That deadline looks tough for the company to meet.”

Meanwhile, The Information says it has also learned “from people with knowledge of the situation” that Waymo is only testing its most advanced prototypes in about 60 square miles, or roughly 5% of the Phoenix metropolitan area adding that these cars have Waymo’s most stable and vetted software, and which are supposed to be the basis for the fully automated robotaxis. “That previously unreported figure suggests that any service launched this year will be severely limited for some time,” it says.