Tom Smith was hired to drive an airport shuttle for a rental car company back and forth from the airport to the rental car company's off-site parking lot. When Smith was hired, he signed a written contract that stated specifically that he was an independent contractor. He was paid every two weeks, based on a rate per mile plus an hourly rate for waiting time. He drove the shuttle times and locations directed by the rental car company and was on-call twenty-four hours day. Is Smith an employee or an independent contractor - and explain the basis of your conclusion.