I was a few hours outside of Los Angeles, tooling down I-5 at the wheel of a sleek Audi A7 on a gorgeous day when a little girl in an SUV smiled and waved. I waved back.

With both hands.

This immediately freaked her out, and she started jumping up and down. All I could do was laugh, knowing my vigorous wave was in no way a safety hazard. In fact, I hadn't touched the steering wheel in more than an hour.

What that little girl didn't know, despite the stickers on the car, was that I was piloting Audi's latest autonomous vehicle, a prototype designed specifically to handle the monotony of highway driving. The, er, driving was not nearly so difficult as the preparation—an arduous task that required a day of training in Arizona, a ream of paperwork and a little bureaucratic wrangling that resulted in the great state of California issuing me a license to operate an autonomous vehicle.

And so it was that I found myself riding along in the car of tomorrow on an autonomous road trip from Palo Alto, California to Las Vegas, where Audi is showing off autonomous tech that may be in showrooms by the end of the decade.

If this A7, nicknamed Jack, wasn't advertising “Audi piloted driving” on its side, you'd never know it wasn't just another German sedan cruising down the 5. All the gadgetry that keeps it squarely centered in its lane at precisely the speed you select is discretely incorporated into the car. It's top-end stuff, too: six radars, three cameras, and two light detection and ranging (LIDAR) units. The computers that allow the car to analyze the road, choose the optimal path and stick to it fit neatly in the trunk. It's remarkably smooth, maintaining a safe following distance, making smooth lane changes, and politely moving to the left to pass slower vehicles controlled by carbon-based life forms. It's so sophisticated that I never felt anything unusual, and in fact the car is designed to reassure you that you need only grab the wheel or tap the brake to immediately resume control.

And that's the most remarkable thing about Audi's robo-car: All that tech recedes into the background. Driving this car is mundane, almost boring. My interaction with that little girl was the most exciting part of the trip. And Audi couldn't be happier about that.

A Baby Step into the Future

It should be said straight away that Jack was designed specifically for highway driving, which, by its nature, tends to be largely uneventful. Now, developing autonomous tech that works only on the highway may not seem impressive when you consider Google's racked up more than 700,000 miles in its autonomous vehicles and has developed a prototype that doesn't even have a steering wheel. It may even seem like a glorified version of adaptive cruise control, lane departure warning and other semi-autonomous tech you can get on many high-end sedans these days.

But the autonomous A7 represents one of the biggest steps forward any automaker has taken toward the day when we're all simply along for the ride. It's a prototype, yes, but Audi says this technology will be in production cars within three to five years.

Josh Valcarcel/WIRED

Audi, like every major automaker experimenting with autonomous driving tech, sees many hurdles—the technology, yes, but also regulatory issues, insurance questions, and consumer acceptance—that must be cleared before we have cars that drive themselves in all places at all times. So it is nibbling away at the edges, planning to introduce autonomous features one by one. It’s a slower timeline than Google's "moonshot" approach, but one that gives everyone time to accept the technology.

“We call it a revolution by evolution. We will take it step by step, and add more functionality, add more usefulness to the system,” says Thomas Ruchatz, Audi’s head of driver assistance systems and integrated safety. Full autonomy is “not going to happen just like that,” where from one day to the next “we can travel from our doorstep to our work and we don’t have a steering wheel in the car.”

Audi’s been developing this technology for more than a decade, and has made remarkable progress in the past five years. In 2009, an autonomous TTS hit 130 mph on the Bonneville salt flats and carved the brand’s four-ring logo into the ground. The next year, the same car completed the winding course to the summit of Pikes Peak—a 12.42-mile ribbon of asphalt with 156 turns–in 27 minutes. That's far slower than Sebastien Loeb's record-setting pace of 8 minutes and 13.9 seconds, but nevertheless impressive for a car controlled exclusively by silicon and steel. The TTS lapped Thunderhill Raceway Park in 2012, and an autonomous RS7 hit 150 mph on the Hockenheimring F1 track in October.

Racetracks are impressive, but they're controlled environments. The real test is on the road. Last year, Audi rolled into CES with a car that could park itself and drive itself through stop-and-go traffic. These features, called, appropriately enough, Parking Pilot and Traffic Jam Pilot, should hit the market before long. Highway Pilot, the tech crammed into the A7 that I piloted down I5, is essentially a more sophisticated version of Traffic Jam Pilot and will follow that to market.

Learning Not to Drive

They don't let just anyone behind the wheel of an autonomous car. California and Nevada—two of the four states and Washington, D.C., that have adopted regulations governing autonomous vehicles on the road—have reams of rules that must be followed. One of them dictates that anyone who gets behind the wheel must be properly trained.

For Audi, this means learning to be a better than average driver. The way Audi sees it, anyone given the responsibility of piloting this device on public roads had damned well be up to the task of taking over, because if you need to grab the wheel, the odds are something's gone terribly amiss. A nicer way of saying this is it takes a lot of skill to be better than Audi’s robot.

Hit these two buttons simultaneously to trigger piloted mode. Josh Valcarcel/WIRED

I was trained at Volkswagen's proving grounds outside Chandler, Arizona (VW is Audi's corporate parent). The day started with a warning that I'd have a better than average chance of experiencing some car sickness, and Audi's security Was. Not. Kidding about there being absolutely, positively no photography. As if to underscore that point, my phone was locked in a secure box when I arrived and a security guard escorted me everywhere.

The proving ground resembles Tatooine, minus the landspeeders and banthas, and it sits downwind of a farm with millions of chickens. There's not a lot to suggest Audi is doing a lot of really cool work here. This is where VW puts its cars through hell, tuning them and adjusting them on a high speed oval, a pair of smaller tracks and an outrageously bumpy stretch of road. There's even a huge shallow pool and a dirt oval, which would probably be lots of fun in an Audi TTS or VW GTI.

After an orientation session in a dreary office where every sign is posted in English and German (a language in which everything sounds like an admonishment), we headed for the track. VW’s instructors, who have forgotten more than you've ever known about driving, led me through a slew of exercises in a GTI that's been driven hard. I had to drive a slalom, then drive it in reverse. I mastered emergency braking and evasive turning and skid recovery. They even made me hone my parking skills. It was a day-long lesson in fundamentals that everyone ought to master before being issued a license. It also was, for the most part, a blast.

Once everyone was confident I knew what I was doing, they taught me how to operate the autonomous A7. This took all of five minutes. Basically, you wait until the car's system determines it's safe to turn on autopilot (meaning you're cruising on a highway, and not near an exit or entrance ramp), then you press two steering wheel mounted buttons simultaneously and let go. It couldn't be easier. That's by design. Even as Audi engineers were developing the backend tech that lets the car handle itself, a design team was honing the UI based on extensive focus group testing in Europe, China, and the US. “We really want to make sure customers understand it,” says Jurg Schlinkheider, Audi’s head of driver assistance systems.

They did an excellent job. Much like the car's exterior, the interior appears utterly stock at first glance. But little things identify it as something special. A small screen below the main infotainment screen tells you when piloted mode is available, when it’s active, and when it will shut off. A line of LEDs stretches along the dash. The lights change color to pass along similar info: they glow bluish-green when the car’s doing the work, yellow when it's time to resume control, and red when you're in command. And there are two buttons along the bottom of the steering wheel—one for each thumb—that you press simultaneously to activate piloted mode.

To communicate the transfer of responsibility to the autonomous system, the steering wheel retracts a few inches. It's just far enough to make it clear you are no longer in charge, but close enough to grab if things go sideways. Because Highway Pilot is for highway driving only, the car makes it abundantly clear when you need to resume driving when, say, the highway ends or your exit approaches. Audi's UI experts chose a combination of audio and visual alerts. Fifteen seconds before the transfer, the bluish-green LEDs turn yellow and a voice tells you autopilot will be turned off. Ten seconds before the transfer, the LEDs turn red and the steering wheel extends to meet you. If you fail to respond, the car activates its hazard lights and slows to a stop, moving to the shoulder if possible.

The A7's trunk now holds eight PCs, which will be condensed into one unit the size of an iPad for the consumer version. Josh Valcarcel/WIRED

Turning off piloted mode is easy: Hit the two buttons on the wheel, press the gas or brake pedal, or grab the wheel with a bit of force and you're in control again. It's just that fast. And it's remarkably sophisticated—drumming your fingers on the wheel (perhaps out of boredom) doesn't do anything, but even the slightest turn will shut off piloted mode. “We put a lot of effort into … making it feel right, so to speak,” says project leader Daniel Lipinski.

I was supposed to take the autonomous A7 out for a few laps on VW's high-speed oval, but a glitch with the adaptive cruise control sidelined the car. Lipinski tried some quick fixes—which, as with all gadgets, included powering down and restarting—to no avail. We gave up for the night and headed for the hotel. Of course, we were halfway there when the engineers solved the problem. They hopped in and met us on the road.

And so it was that I found myself behind the wheel of an autonomous vehicle for the first time. I wasn't confined to the safety of a track, but on a busy street, among real people in real cars—at night. The issue here is the street has traffic signals, which the Highway Pilot system is not programmed to recognize (you don't see a lot of traffic signals on I5 or I10). So I used piloted mode for cruising along, then reverted to manual mode when approaching intersections. Lipinski suggested I let the car do all the work, since it is programmed to maintain a safe following distance and avoid hitting anything in front of it. Audi's engineers hadn't tried this before, butLipinski had enough confidence in the tech to let me be the first to test it.

Damned if it didn't work at the next light, bringing the car to a safe stop two car lengths behind the guy in front of us. “We didn’t know it would do that!” Lipinski said with some excitement. That hammers home a fundamental point about autonomous technology: It is remarkably advanced, yet still in its infancy. It works very well, yes. But we don’t really know exactly how well. And it may, for better or worse, very well surprise us with what it can do.

Safety and Comfort, Little by Little

Once I made peace with the fact I wasn't in control of the car—something that took roughly four minutes—seeing that little girl freak out was the most exciting part of the drive. Frankly, autonomous vehicles are boring. That’s how it’s meant to be: Piloted driving is about safety and comfort.

Every decision the car makes comes down to two questions: Is it possible (i.e., safe and legal) and is it beneficial (i.e., does it make the ride more comfortable). Tuning the system to properly assess and balance these two things and speed up, slow down, change lanes, or make turns smoothly has been key to developing the technology. At one point during my drive, the A7 moved effortlessly into a relatively small slot in the right lane to make way for a faster car approaching from behind. It was seamless. That kind of decision-making and maneuvering is quite advanced, yet needs fine tuning before commercial production can begin. Audi's team hasn't yet worked through every situation the car may encounter, or settled on a balance between maintaining a steady course and making tiny adjustments to avoid every single tiny thing the sensors pick up.

As my excitement turned to boredom—I5 just goes on and on and on and on, and then you've got I15—it became easy to see Highway Pilot as a feature drivers will embrace. And it suggests Audi and other automakers are on the right track rolling out autonomous tech one or two features at a time. Knowing I can immediately resume control of the car, and feeling a conventional steering wheel in my hands and pedals beneath my feet, makes the transition to being chauffeured by a robot easier to embrace. It's a more sophisticated version of the adaptive cruise control we're already using. In that way, the A7 isn’t a self-driving car, it’s a luxury sedan that can, with my approval, make driving safer, easier and more relaxing. “Our experience is that our customer wants to accept first and understand first what they are getting, and what the limitations are as well,” says Schlinkheider. “Accept our function, and learn first how it works, and get used to it.”

A piecemeal approach also is easier for automakers, and regulators. Making one swift jump to fully autonomous driving, as Google is pursuing, requires perfecting all of the technology and considering every possible scenario. The car must know exactly what to do, everywhere, under every condition. It’s a massive undertaking, and it’s easy to see why the automakers want to take things one step at a time.

Audi is allowed to test its car in California and Nevada, but the states have different regulations—and license plates. Josh Valcarcel/WIRED

Shortly after crossing into Nevada, we pull over in Primm, a dusty town with a couple of casinos, an outlet mall and about 400 people. We've got to swap the license plates, because California and Nevada have different rules regulating autonomous vehicles. It underscores why Audi and other automakers want to see the feds take the lead regulating such cars. “It’s good to have clear regulations, on what to do to test those systems safely,” Lipinski says. The patchwork of rules is, at this point, one impediment to marketing Highway Pilot. As the rules in each state currently stand, autonomous technology is limited to prototypes, not production vehicles.

Building the Central Brain

There are other challenges to marketing this tech, not the least of which is packaging all the sensors and computers. Consumers don't want a car that looks like it was used to rob a CompUSA. Each of the eight PCs in the back of our A7 serves a different function. They control data logging, planning a path, controlling steering, braking, and acceleration, operating the near field cameras, and fusing sensor data. When it’s time to go to market, Audi will consolidate these functions in a single computer, called the zentrale Fahrerassistenzsteuergerät, or zFAS. It’s “a central brain like the one we have in our head,” says Thomas Meuller, Audi’s head of development of braking, steering, and driver assistance systems. Two years ago, the zFAS filled the trunk. When Audi rolled into CES last year, it was a bit smaller than a shoebox. By the time Highway Pilot sees production, it will be the size of an iPad.

The car I took to Sin City hasn't seen that downsizing in tech because it’s a research vehicle. Working with individual PCs makes it easier to tinker with the software, and this phase of development involves a whole lot of tinkering. There’s no sense in combining the parts until they’re much closer to a final product. The idea, Schlinkheider says, is “just be super flexible, try out different things. And then when it comes to series production, to the option that our customer can buy later on, that all will be running on the zFAS controller.”

After the drive from Silicon Valley to Vegas, the car feels ready for showrooms. But Audi says there's more work to do. The rules that govern how the car adjusts its speed and position need more fine tuning, for example. The Audi team has put some 50,000 miles on the Highway Pilot feature, and will rack up many more before going public. From deer to sinkholes, highways hold a lot of potential hazards, and the system has to be prepared for them.

During my time at the wheel, I never needed to take control from the car, except to take an exit. I turned the system on and off to get a feel for how it works, but I only felt the need to grab the wheel once–and only then to accommodate the Audi camera crew in a passing car. The photographer wanted me to move into the right lane. The lane change would be safe, yes, but not beneficial, because it would put me behind a lumbering truck.

The car didn't see the logic in that, and had no reason to oblige the photographer’s request, so I grabbed the wheel, put on my turn signal, and changed lanes. It was almost as exciting as spooking the girl in the SUV.