text: The cars have sensors to alert the drivers if they are heading towards something dangerous or the car deal with the circumstance they're in. The cars have gone miles without crashing but still need a driver. What if the car is in traffic issues where the driver needs to be in control and the sensor is broke and can't alert the driver? The driver could stop paying attention for one second and the car could wreck. The sensors could also malfunction and run into something when it was supposed to brake.