A series of letters sent by autonomous-vehicle (AV) developers to Democratic US senator Ed Markey of Massachusetts sheds the most light yet on the human side of robot vehicle operations. In the documents, submitted to Markey as part of an investigation into self-driving-vehicle technology and released on Tuesday, seven companies, including Tesla, Amazon-owned Zoox, and Uber- and Nvidia-funded Nuro, released new details about their “remote assistance” programs.All the companies that responded to ...