Back in February, I got very excited about the Cadillac CT6 sedan. It didn't handle better than its competitors. It wasn't faster or better put-together. But it did come with Super Cruise: a cutting-edge semi-autonomous driving assist that combines HD mapping and a proper driver monitoring system. Super Cruise is geofenced, so it only works on divided lane highways—and only when it knows you're looking at the road ahead, thanks to that driver monitoring system. That made it the best such system on the market—yes, even better than Tesla's Autopilot—and it seems Consumer Reports agrees . On Thursday it published its first-ever ranking of semi-automated driving systems, putting Super Cruise in at the top.

The proliferation of advanced driver assistance systems (ADAS) across the auto industry has been quite a thing to watch. Some features are there for driver convenience, like adaptive cruise control and lane keeping. Others—collision warning or emergency braking for example—are more consciously safety features. But the rollout can also be a bit bewildering, particularly when it comes to relative performance. The problem is that comparative testing is easier said than done, at least without the right resources.

The Insurance Institute for Highway Safety is one of the few groups to have been doing this with some rigor. Now Consumer Reports joins the fray. Like IIHS, its first results are from a rather limited sample—in this case, it tested Super Cruise in a Cadillac CT6; Autopilot in Tesla Models S, X, and 3; ProPilot Assist in an Infiniti QX50 and Nissan Leaf; and Pilot Assist in a Volvo XC40 and XC60. (With regard to software versions, Consumer Reports says it evaluated the systems as they were operating in September 2018.)

"We have been evaluating these systems on a case-by-case basis for a few years, but we are at a tipping point where they are now going mainstream," says Jake Fisher, director of Auto Testing at Consumer Reports. "Stacked up against each other, you can really see significant differences. The best systems balance capability with safeguards—making driving easier and less stressful in the right situations. Without proper safeguards, over-reliance on the system is too easy, which puts drivers at risk."

Consumer Reports says it tested "not only how well the technology works but also how well it monitors driver engagement and reacts if drivers don't respond to warnings." For that reason alone I'm not surprised Super Cruise won, as it remains the only system to take driver monitoring more seriously than using a torque sensor to measure steering input. It also rated GM highly for making it clear when it was safe to use the system.

Tesla got good marks for Autopilot's capabilities but did not do well when it came to monitoring or alerting its driver. ProPilot Assist came third, with Volvo coming last, in part because its displays can cause mode confusion. I don't do this job for validation, but it's always nice when another august publication comes to the same conclusion I have—and I agree entirely with Consumer Reports' take.

Super Cruise is the most complete system on the market, and anyone who is serious about offering this level of driver assist needs to provide proper driver monitoring. (GM also needs to hurry up and make it available in more models.) Autopilot is extremely capable but doesn't have your back the way Super Cruise does. ProPilot Assist is indeed very good about avoiding mode confusion. And Pilot Assist is the only system with which I've experienced mode confusion, assuming it was engaged when it wasn't. Twice.

As a responsible arbiter of information, Consumer Reports also stresses that these kinds of assists are really there for convenience and that operating them introduces new safety risks. As we stress every time we cover the topic, no matter what a car calls its combination of adaptive cruise control and lane keeping, it's not responsible for situational awareness: that responsibility lies with the human in the driver's seat.

Listing image by Cadillac