text: The self driving cars will cost a lot less money on gas, nearly 50 percent of gas will be saved. But the money that you save on gas, doesnt make up for how much the car will cost, how much the upgraded roads will be, and the risk you are taking letting a computer drive you around wherever you want to go, even when you have to do some of the driving yourself. The cost of the gas does not make up for how much everything else will cost.