LAS VEGAS—Have we mentioned that self-driving cars were a big thing at CES this year? Among all the drones and connected fridges and 8K TVs, companies like Ford and BMW and Audi were all on hand to update us about their respective visions for autonomous driving. We were fortunate enough to sit down with Audi's Thomas Müller, who heads up autonomous technology at the company, to pick his brain about where the Ingolstadt-based OEM is going with its robot cars.

Audi is currently working on fully autonomous cars, but these cars are research vehicles. However, right now, it will sell you a car that's autonomous to almost the same degree as Tesla's Model S (minus Autosteer and Summon), which the National Highway Traffic Safety Administration classifies as level two self driving. (Level four would be a car that goes from A to B with no human intervention, something that most people say is at least five to 10 years off). I recently had cause to put one of these—an A7 TDI—to the test on a drive from Washington, DC to Columbus and back again, and I jumped at the chance to pick Müller's brain about how it works and what's next for the company.

For one thing, terminology matters. "Today we have all the cutting edge technology of a level 2 system," he told Ars. "In the new Q7 there's some new technology [over the A7 we drove]. As soon as we call it 'pilot', it's a level 3 system. With some of our competitors they call it pilot or autopilot, but it's still cruise control. It's misleading and the customer needs to understand [what the system is and isn't capable of] which is why we call it 'assist.'"

"With traffic jam assist in the Q7, if you're driving up to 60km/h, the car recognizes it's in a jam and as soon it does it will give you a different HMI (human machine interface) on the dashboard, and you'll have a combined cruise control and lane keeping, and at very low speeds you can take your hands off the wheel for longer," he said. (We should note we tried a similar system from Volvo last year, fitted to its new XC90 SUV.)

"The second thing we're bringing to the US is called predictive control. It's the first generation Audi, which combines the information from maps and road signs with adaptive cruise control," he said. Here, Müller is talking about the normal GPS navigation maps, not the HD machine-readable maps from companies like HERE (which Audi is now part-owner of). "We made a layer where we extract the curvature of curves, information about roundabouts and crossings, and we adapt the speed of the cruise control. Something you have to do [manually] today, slowing down when you enter a city or have a curve to negotiate, the car will do for you. I think it's a huge advantage for the customer and one more step in level 2 functionality, trying to get it to the border of true autonomous driving," he said.

This obviously requires a lot of sensors. Right now, that means cameras and a Mobileye EyeQ3 chip (which also enables Tesla's Model S Autopilot), two long-range radar sensors in the headlights, ultrasonic sensors around the car, and midrange radar doing blindspot detection. "So there's a lot of sensors around the car doing sensor fusion," Müller explained.

Something that I've been wondering since my A7 road trip was how the car coped with turns, particularly when there was a car directly ahead longitudinally when both drivers were turning. How does the car know I'm not going to have a collision?

"We sensed curves by analyzing the lines, but at low speed, the traffic jam assist wouldn't work in an urban environment because you're driving so close to the car in front it can't see the lines," Müller said. "What we implemented in the Q7 and new A4 is a corridor—the most probable corridor you should follow. You have a lot of information that goes into that. One of them is lines—when you see lines, take them. The other one is what the cars in front are doing."

Audi uses the car's radar sensors to look several cars ahead (because the radar is mounted low enough to be able to see underneath cars ahead). "One more source is what the cars to the right and left are doing, and when you put all of that together you have the most probable path the car should follow in a traffic jam," Müller told us.

Audi's next step is applying the technology from traffic jam assist to higher speed driving. Right now, adaptive cruise control and lane keeping will let you take your hands off the wheel for about 15 seconds before ordering you to take control. Soon, that feature will change.

"On the highway, following the lines is reasonable, because you have more distance to the car in front of you, but we want to take that level of intelligence to higher speed," Müller said. "Sometimes you have boundaries that are looking into the road or you have a truck close to you where you'd drive a little further to the other side of your lane. All these things you and I do naturally while we drive, and take it into consideration with our [self-driving] logic, so that it feels like me driving."

We also were curious about systems further off into the future. With regard to piloted driving, Müller told us Audi has two main areas of research and development. The first one is with Jack, a car that drove from San Francisco to Las Vegas. "That car has the whole sensor package on board, and their task is understanding what's happening around them. There's millions of tons of raw signals, and you have to extract the right information," he said. The second area of research is with Bobby and Robby.

The point of the research is to understand how to best model driving behavior and how to teach a machine to cope with problems. "Every time you develop autonomous functionality or even driver assistance systems, you have to think about this," Müller told us. "You need to consider what the critical hazards are that could happen, and you need to manage them."

"For example, how do I manage an autonomous steering evasive maneuver around something without spearing off the street on the next corner, which could be even worse? Both parts are very important, and when you put them together you get to specific scenarios, and then you get to our roadmap [for piloted driving]," he said.

As we've found with Volvo and BMW before, Audi doesn't think self-driving cars are going to involve seats that swivel 180 degrees when they're driving us around. "Our vision is not robocars driving around and picking people up and dropping them off," Müller said, although Audi is working on self-parking technology. At the end of the day, he said that a self-driving Audi still had to be fun to drive, otherwise it wouldn't be an Audi.

Listing image by Audi