If you’re wondering why you don’t have a self-driving car yet, you should know that you’re part of the problem. Maybe even most of the problem. But don't worry. Cadillac has a solution.

When it comes to semi-autonomous systems—cars that do some of the driving, but leave the tricky stuff to humans---the biggest hurdle isn’t the technical challenge of making a car safely drive itself. It's ensuring that you're alert and ready to grab the wheel if a sensor craps out, someone cuts you off, or any number of other sudden and random things happens.

Engineers call this the handoff problem, and it's so tricky that companies like Ford and Google's Waymo have given up on partial autonomy because they figure it's easier to go straight to full autonomy and cut you out of the equation entirely. But a few think it's worth pursuing. Tesla has done it pretty well with its Autopilot system, for example. Cadillac thinks it might do it better.

General Motors

Super Cruise arrives later this year on the company's flagship CT6 sedan. It renders you all but irrelevant on any divided highway in the US or Canada because a front-facing camera, military-grade GPS, and an array of radars keep the car within its lane and a safe distance from everyone else. I took it for a spin on Wednesday, and it handled Interstate 280—which winds through Silicon Valley—with aplomb, even at 80 mph (it maxes out at 85).

Like other semi-autonomous systems, it demands you remain alert and attentive so you can take control in an emergency. Tesla and Mercedes-Benz do that by insisting you give the steering wheel a nudge every so often. The downside there is grabbing the wheel can inadvertently disengage the autonomous system. Worse, it doesn’t require you actually look at the road.

To ensure you're paying attention, Cadillac developed what it calls the first truly hands-free driving system. A gumdrop-sized infrared camera on the steering wheel tracks the position of your head. Look left, right, or down (at your phone, probably), for more than a few seconds and a green light bar in the steering wheel flashes. The higher the car’s speed, the less time you have to look away. Keep ignoring the road, and you’ll hear a chime, feel a buzz through the seat, and see that light turn red and start flashing. (You're colorblind? Different colors pulse at different tempos.) Refuse to respond at all and the car turns on its flashers, slows to a stop, and summons OnStar to make sure you haven't had a heart attack or something.

To ensure Super Cruise never faces obstacles it can't handle—intersections, pedestrians, traffic lights—Cadillac programmed it to only work on divided highways. And, it dispatched a crew to map every mile of those roads in the US and Canada.

That knowledge base offers two advantages. First, if your lane is about to end or you're approaching a toll booth, the car gives you plenty of time to assume control. Second, if the camera stops working or you go through a tunnel and the GPS loses its signal, the car can keep driving itself, using the map, its speed, and its steering angle to maintain its exact position. (Cadillac plans to periodically update those maps through over-the-air software updates, but not to change the car’s driving software once it’s in the customer’s hands.)

Cadillac hasn’t yet revealed how much it will cost to add Super Cruise to your CT6, which starts at $54,000, or just when you'll see it in cars. But it’s coming soon, and if you’ve got the cash, get ready to finally take your hands off the wheel.