text: My First Reason , That They Use Half The Feul Of Today's Taxis , Is Because Who Wants To Keep Causing Global Warming By The Gases That Come Out Of Your Car ? In Order To Even Have Driverless Cars We Have To Have An Earth To Keep Them On . Global Warming Is Basically Over Heating Our Earth And Is Caused By Many Things Including The Gases That Come From Cars . Using Half The Fuel Of Today's Cars For A Far More Better Transportation Sounds Pretty Good To Me .