text: Okay, so smart raods are a terrible idea. What about smart cars? Google came out with a Toyota Prius. The prius uses postion-estimating sensors on the left rear wheel, a roatating senor on the roof, a video camera mounted near the rearview mirror, four automatic radar sensors, a GPS receiver, and an inertial motion sensor. Sounds cool right? There are a couple problems with all of this stuff on a car. The first problem being that if one thing broke it would be super expensive. the second problem being if one thing broke nobodywould be able to drive at all. The last problem with all of the gudgets on the car is having the extra weight on the car would make the gas milage go through the roof.