The National Highway Traffic Safety Administration has launched an investigation into crashes it said occurred while Tesla vehicles were operating with a parking feature that allows owners to summon a car from a parking space without anyone being in the vehicle.The preliminary investigation into an estimated 2.6 million Tesla vehicles with the “Actually Smart Summon” feature was disclosed Monday. The agency said that it is aware of “multiple crash allegations” where the user was unable to prevent a collision, either due to line of sight or reaction time issues. It is the latest probe by the federal safety regulator into self-driving features of Tesla vehicles.It comes just two weeks before President-elect Donald Trump takes office and Tesla CEO Elon Musk, a major supporter of Trump during the campaign and since the election, starts to officially exert his influence over a wide range of federal government policy.Shares of Tesla have climbed …