Tesla Autopilot System Warned Driver to Put Hands on Wheel, Investigators Say

The Model X electric, sport-utility vehicle accelerated in the final seconds to about 71 miles an hour before the March 23 crash in Mountain View, Calif., according to a preliminary report from the National Transportation Safety Board. The report comes as auto makers and Silicon Valley are testing technologies that allow for varying levels of automation behind the wheel. Those include systems with driver-assist features as well as those that enable fully self-driving vehicles. Fatal crashes have fueled concerns about whether driverless technology is ready for the real world. A Tesla spokeswoman pointed to a previous company blog post about the incident that touted the safety of its vehicles.