MILFORD, MI – General Motors joins the salable autonomous-vehicle market with the launch this fall of the ’18 Cadillac CT6 with available Super Cruise, a hands-free driving technology that is superbly integrated and easy-to-use if not a skosh late to U.S. dealers.

Operating the technology requires regular driver supervision and it works only on limited-access highways without cross-traffic intersections or stoplights. But once activated, the driver can pull his hands from the wheel, peek out the window here and there and leisurely let adaptive cruise control manage the following distance of cars ahead.

“This is hands-free, (but) the driver is responsible for supervising,” says Daryl Wilson, lead development engineer-Super Cruise at GM.

Super Cruise could be considered Level 3 autonomous-driving technology, or conditional automation where the car is in control and constantly monitors the roadway but will re-engage the human driver when appropriate. However, GM refuses to assign it SAE taxonomy as other automakers have with their systems.

“Levels are interpreted differently across the industry,” says Pam Fletcher, executive chief engineer-autonomous and electrified vehicles at GM. “There are so many nuances.”

Besides, she adds, “Customers don’t care. So we just say, ‘Hands off on the highway.’”

The 3-year-old, Level 2 AutoPilot system from Tesla on the Model S and Model X can be used under a broader range of conditions, although the startup electric-vehicle maker has toned down its rhetoric around the system and some functionality because of crashes. Its newest models reportedly contain software to permit full autonomy, or Level 5 capability, but it is unclear how much of that Tesla will unlock for its customers due to regulations.

Volvo’s self-driving technology might be further ahead than any in the industry, but it is limited to a small test group in a tightly geo-fenced area of Sweden. No retail availability, in other words.

The next-generation Audi A8 due in 2018 with Traffic Jam Pilot is billed as Level 3. It can be used at speeds up to 35 mph (56 km/h) during limited-access-highway driving and, unlike Super Cruise, comes with technology to park remotely in garages and surface lots.

Tesla’s recent trouble with driver shenanigans aside, those three automakers have won themselves lots of positive press by getting autonomous technology on the street, or at least in the headlines, ahead of Cadillac. GM originally intended to roll out Super Cruise on the CT6 last year but safety concerns delayed the project.

But don’t sell Super Cruise short. During a brief test drive here near GM’s suburban Detroit proving ground the system performs flawlessly on the freeway, keeping the big CT6 luxury sedan dead-center of the driving lane. Even through sweeping bends in the roadway and a construction-zone traffic shift, Super Cruise confidently guides the CT6 ahead at speeds up to 85 mph (137 km/h).

Super Cruise steers the car smoothly, too, surprisingly devoid of constant little adjustments to maintain its path of travel. Acceleration and braking is silkier than a human could perform. If the driver applies the brakes manually, Super Cruise will disengage, but not if he accelerates. Drivers must make lane changes themselves, but once the car is centered back into the lane Super Cruise quickly restarts, and it’s time to again ease back and enjoy the ride.

The system also is superbly integrated. Activating Super Cruise is no more difficult than a traditional cruise control system and a green light bar along the steering wheel indicating it is in operation does not tarnish an elegant interior.

Super Cruise uses two key technologies, a sophisticated driver-attention system to keep the driver engaged and highly detailed Lidar map data of every highway in the U.S. and Canada.

The driver-attention system uses infrared lighting from a small, industry-exclusive camera mounted to the steering column to track the driver’s head and eyes. Go ahead and wear shades while operating Super Cruise, as it will penetrate 99% of the sunglasses on the market, GM says.

If the driver turns his head from the roadway a split-second too long, alerts will bring his attention back. The green light bar blinks red until Super Cruise determines if the driver is looking straight ahead again. If inattention persists, a series of escalating alerts, including haptic pulses from the seat and voice prompts, alert the driver.

In the most dramatic scenario, where, for example, the driver has become ill and cannot regain control of the car, Super Cruise will bring the vehicle to a stop safely and connect it with an OnStar advisor to contact emergency responders, GM says.

Another key element of the driver-attention system is haptic sensors inside the steering wheel, which sense when a driver’s hands have returned to the wheel.

The other half of the technological puzzle is a fusion of data from precision Lidar mapping, real-time cameras, sensors and GPS. Super Cruise does not use onboard Lidar, so GM partnered with Atlanta-based GeoDigital to perform Lidar mapping. GM owns the data and it will be updated over the air to the cars as necessary. GM discovered GeoDigital through an investment in the company by GM Ventures, the venture-capital arm of the automaker.

Sunnyvale, CA-based Trimble supplies real-time GPS to Super Cruise. It locates the car within 6.5 ft. (2 m). Trimble technology already exists on every OnStar-equipped GM vehicle on the road today. Cameras detect right- and left-lane marking to center the vehicle and provide its directional heading. The radar works with the cruise control to maintain following distances.

Enter a tunnel and Super Cruise will remain engaged for up to 0.6 miles (1 km) using dead reckoning.

GM has not yet determined pricing for Super Cruise. It will be standard equipment on top-of-the-line Platinum models and optional on Premium Luxury trim levels.

Initial availability will be restricted to the U.S. and Canada and is subject to limitations imposed by state and local governments, such as New York where hands-free driving is prohibited. China will get Super Cruise soon, although GM executives along for the drive here would not speculate when because the highway infrastructure there is more challenging to manage.

So what comes next for Super Cruise? CT6 Chief Engineer Lyndon Lie will not divulge much but agrees it would be logical to assume a lane-change feature for overtaking cars on the highway.

It also is worth noting Cadillac President Johan de Nysschen has said driverless cars are not the future for Cadillac, because removing the driving experience entirely is not within the spirit of the brand. So look for future, fully autonomous technology that Super Cruise lays the ground for at another brand.

However, this much is for sure: GM may have moved deliberately with Super Cruise but it delivered a safe, reliable technology that has put the automaker in the fast lane to an autonomous future.

jamend@wardsauto.com