According to the Washington Post, Musk's Tesla (TSLA.O) is preparing to launch a taxi service in California, which may eventually allow paid passengers to travel around the state in self-driving cars. Tesla submitted an application to the California Public Utilities Commission late last year to use its vehicles to transport passengers. The company is currently approved to test driverless cars in the state, but people will be able to summon their taxis from Tesla for free if additional permission is obtained.