Rebecca Tinucci has just been assigned one of the toughest jobs in transportation. She was named chief executive officer of Uber Freight after its founder, Lior Ron, jumped ship to become the chief operating officer of Waabi, a driverless large-truck startup.Tinucci, a Tesla Inc. veteran, was hired by Uber Technologies Inc. to help develop infrastructure for Uber drivers who own electric vehicles. She’s now in charge of solving Uber’s freight problem. The ride-hailing company made a bet that usi...