text: Driverless cars have sensors in them that apply force when there is danger but how can you be for certain that something won't block a specific necessity of the sensor and make the sensor invalid to apply force. If the sensor didn't detect a sign of danger when there was a pedistrian or wall or car in front of them. The cars sensors would not be able to automaticly brake. Some driverless cars also have cameras in them. How do we know that what the camera sees won't mistake it with a different action. The sensor on the roof updates the car with a 3-D image of its surroundings. This 3-D imaging could pick something up that is different than what it makes or it could make the thing it saw and apply force when they needn't be any.