text: There are many things that have been done to make this idea become reality. For example, Google's modified Toyota Prius uses position-estimating sensors on the left rear wheel, a rotating sensor on the roof, a video camera mounted near the rearview mirror, and a GPS receiver. With modifications on these resources, they could potentually work. Of course, the driverless car will not be 100% driverless. The driver would need to be alert and ready to take control when needed. GM has developed ways to alert the driver. For example, they have made driver's seats that vibrate when the vehicle is in danger of backing into an object. Google and GM have taken great precautions in developing the driverless car.