A lot of what we're doing with the urban challenge is very focused on the moment. We have to get the car moving, we have to keep it from running into things, and so on. For the challenge, of course, this is vital. There's only a certain amount of time for us to do things in, and plenty to do. So we stay focused.
Still, for all its complexities, the Urban Challenge is very simple compared with real life. Oh, from an abstract viewpoint, cars are just boxes that move around other boxes, and for the Challenge, we can think of it that way. However, in real life, everyone who's driven knows this isn't entirely true. It's more true in some places than others, but it's still not everything.
Let's take a 4-way intersection as an example, with everyone having a stop sign. Legally, it's a very simple procedure. You drive up to the stop, and see if anyone else is there. If someone was there first, you wait until the people who had arrived earlier go, then you go. Very simple, no problems there.
When you add people into the mix, though, things change. Sometimes people are distracted, and don't pay attention to who was at the intersection first. Some people have different ideas of what it means to be properly arrived. Is it the first person whose front bumper lines up with the stop line? Is it the first person who comes to a complete stop near the stop sign? Then there's the fact that not everyone cares about intersection precedence rules. Some people feel that they have the right to go through the intersection just because they are more important than you, or are in a bigger hurry, or have a bigger car, or whatever.
So we don't just pay attention to when the cars arrive. We can't just pay attention to when they arrive. Instead, when the situation is ambiguous, we look at the other drivers faces, and we gesture to them, and we negotiate the precedence order. The rules change, because we believe that we can change them. Unless one of the cars is a police car. We tend to skip the negotiations then.
An autonomous car can't negotiate. The cars that the teams are making now don't really have any faces. They can't look at the other drivers and indicate, "Hey, I'm a computerized car, and chances are good that I don't care that you're in a hurry, because I know the law. Oh, and I have a camera, so I'd be happy to present evidence in court if you run into me." Without that communication, situations become more ambiguous.
One way to deal with this is to make sure that everyone knows that the car is autonomous. Put a big warning sign on it, much like a student driver. Just as with a student driver, this will warn other drivers, "Look, whoever is driving that car probably doesn't want to deal with you driving like a moron, so do things properly, okay?"
That gets you some of the way to a solution of people understanding an autonomous vehicle. Still the other drivers aren't the only trouble. What about the passengers? Sure, the early autonomous cars won't carry passengers. They'll be all about transporting goods and supplies across dangerous territory for the military, and the whole point will be not to have anyone else in the car. But this isn't just about the military; it's about the future we were promised. You know the one with the jetpacks and the cure for the common cold and the robot butler and the car that drives itself around. Your robotic chauffeur. That's part of the future we were promised, and we want to make that future happen.
Still, with an autonomous car, how do you know it's paying attention? How do you know it sees the deer on the side of the road, or the big pothole, or the guy swerving back and forth in oncoming traffic. Normally, you can point these things out to the driver, or at least pull in a little breath and grasp the handle by the passenger window, and the driver can reassure you that it's all okay. Or you can see where the driver is looking, and get an idea of what has been noticed and what hasn't.
With the robot driver, especially the robot driver who is not really there, but is built into the car, you may not have any of that. It'll be necessary, though. You'll need to have an idea of what the car knows, and what it plans to do, or riding in the car will make you a nervous wreck, especially in the beginning, and especailly if anything ever goes wrong. If there's one problem, even if it's not the car's fault, but you can't tell if it was the car's fault, you'll not know whether to trust it any more. And that would be bad.
So it will be important to give the passengers, and the other drivers, proper feedback that they can understand. Let people know what's happening and what the car intends to do. Trust will need to be built, and building trust will require communication. Just one of the many things that we have to consider when we try to build the future.