Cadillac Super Cruise, the luxury automaker’s hands-off driver-assistance system, will by the end of the year work on more than 200,000 miles of highway in the United States and Canada, 35 percent more territory than it covered when it launched in 2017. The bulk of the new miles come from divided highways—the sort of road where Tesla’s Autopilot system has suffered two high-profile deadly crashes, and where Cadillac’s engineers are confident their system can do better.
Alex Davies covers autonomous vehicles and other transportation machines for WIRED.
To make the expansion possible, Cadillac ramped up its cartography. Unlike Autopilot and similarly pseudo-self-driving systems offered by the likes of Nissan, Super Cruise strictly limits where the driver can use it. As it developed the system, Cadillac hired a company called Ushr to drive every mile of limited-access highway in the US and Canada, using a lidar laser scanner to record all the lane lines, tollbooths, curves, merges, splits, and other features. It trimmed away some useless lidar data (like roadside trees), and compressed what was left until it fit easily on a car’s computer. The resulting map helps the car anticipate things like sharp curves, but it has a more important function.
By matching the car’s location (using GPS) to the map, Cadillac disables the system where it’s not confident that the system can handle the driving. Maybe the car’s lane is ending, or it’s approaching a toll booth, or reaching the point where the five lanes of the Bay Bridge split into the various highways of Berkeley and Oakland—anything that demands more than staying between the lane lines and a safe distance from the car up ahead. About one-third of a mile before the cutoff point, lights in the steering wheel go from green to red, the driver’s seat buzzes, and the dashboard reads, “Super Cruise disengaging, take back control.”
For the initial Super Cruise release in 2017, Cadillac and Ushr only mapped limited access highways, the sort with on and off ramps. Now, it’s adding divided highways, which aren’t quite so simple. Cadillac and Ushr tweaked their mapping protocol to account for a few new features, including the stop signs and traffic lights you occasionally see on such roads. Those fall under the no-go-zone for Super Cruise, since the system isn’t designed to handle them. But the car will cruise through uncontrolled intersections where it has the right of way.
That raises the spectre of two Tesla crashes, one in May 2016, one in March of this year. In each case, a driver using Tesla’s Autopilot system died after colliding with a truck turning across its path. Neither driver was holding the wheel in the seconds leading up to the crash, and neither hit the brakes before impact. It’s unclear why the cars didn’t stop on their own, but the shortcomings of the radars they use are a plausible explanation. Cadillac uses the same sort of radar, but the automaker’s engineers are confident in their system’s safety.
“The standout is the driver attention system,” says Mario Maiorana, Super Cruise’s chief engineer. He’s referring to the infrared camera that sits on the steering wheel cowl, watching the driver’s head position and gaze. Look away from the road for more than a few seconds, and you get a buzz in your seat, plus visual and audio warnings to watch the road. Ignore those, and the system will shut itself off, throw on the hazard lights, and slow to a stop. Audi uses a similar setup in its Traffic Jam Pilot, but most competing systems, including Tesla’s, rely on a torque sensor in the wheel to verify the driver is paying attention, a setup easily defeated by a well-placed orange or habitually tapping the wheel without bothering to look at the road.
Current Super Cruise drivers—the system is currently available only on the CT6 sedan, and moves to the CT5 sedan next year—have to trek to their dealer to get the software upgrade that will let them take advantage of the newly added parts of the map. The process is free, and takes about an hour. After that, Cadillac will send out the updated maps via over-the-air software updates starting this summer, and into the fall.