If the car of the future is going to be able to drive itself, its appetite for data will be almost insatiable.

That's because to drive themselves safely and reliably, cars will need numerous sensors to gather as much information as possible about their constantly changing surroundings, and powerful onboard processors to analyze that information. Some data may flow to remote computers for crunching, too. Cars will need to talk to each other, as well, for a better sense of how traffic patterns in the immediate area are developing. And all of this will have to happen lightning fast.

"Building a robot that can understand everything that is going on around it—knowing exactly where the stop signs are, decoding the lanes around it and never mistaking mailboxes for pedestrians on the side of the street—is really hard," says Edwin Olson, a University of Michigan professor who is working with Ford Motor Co. on autonomous-car research. "The variety of odd situations that a vehicle can find itself in is so high."

Here's a closer look at what's involved in making all this happen.

Gathering Data

It all starts with a clear picture of a car's immediate surroundings as it zips around. Car makers are experimenting with different types of sensors and different combinations to figure out the best way to detect moving and stationary objects and gauge their relations to the car and to one another.