text: One problem is money--how will people be able to afford these driverless cars? For example, Google's modified Toyota Prius uses position-estimating sensors, a rotating sensor on the roof, a video camera, four automotive radar sensors, a GPS receiver, and an inertial motion sensor. The combination of all of these is absolutely necessary for the driverless car to have the skill of a human at the wheel. The combination of all of these is also very costly. Only a minority of the population would be able to buy such a car, and just because they're able to, doesn't mean they will be willing to. Many people might think the car isn't worth that much money if they can drive themselves. Economic problems will always be around.