Cadillac has made no secret of its plan to tackle the German luxury-car leaders, but it hasn't quite cracked the code yet. The CT6 is good, but it lags in the technology stakes compared to the semi-autonomous showoffs you can buy from Mercedes and BMW. The company has taken a baby step towards matching its European rivals with the new Super Cruise system.

According to Cadillac, the secret to Super Cruise lies in LiDAR. Every car manufacturer has a different take on the best way to do semi-autonomous driving at the moment – Tesla has put its faith in a combination of radar, camera and GPS data, while the likes of Nissan and Subaru are relying on stereo cameras alone. Along with the standard array of cameras, radar and GPS inputs, Super Cruise draws on a LiDAR map database for more detail about the road ahead, including hills and corners.

The question with map-intensive self-driving systems is: "what if you're driving on an area that isn't mapped?" The answer, in the case of Super Cruise, is to simply map every single mile of limited-access highway in the USA and Canada.

The light on the steering wheel in the CT6 is used to catch the attention of dozy drivers

Even though this LiDAR mapping data is combined with information from the set of cameras and radar units mounted around the car, the system clearly relies heavily on LiDAR data. It can only be used on highways that have already been mapped, limiting its effectiveness to North American highways that were complete when Caddy was collecting its information. When activated, it will take control of steering, throttle and brakes and when it's switched off, the sensors act as a lane-keeping assist system.

Although this is the same basic capability you get from the BMW 5 Series and Mercedes E-Class, limiting Super Cruise to pre-mapped highways is a touch unlikely to win fans outside of America. According to Cadillac, North American spend the majority of their time on urban and suburban highways, but that isn't necessarily the case in Europe and Asia.

Short of mapping every mile of highway in the world, the approach used in the CT6 Super Cruise system simply won't work on a larger scale, leaving global GM brands like Holden and without the tech.

One of the biggest issues with semi-autonomous systems like this is driver attention. Even though their systems are able to handle things most of the time, manufacturers (all of them) say the driver needs to be ready to take control in case of an emergency. Of course, saying the driver needs to stay awake is one thing, making sure they actually do is another.

The infrared sensor and camera in the CT6 is used to make sure the Super Cruise 'pilot' is being attentive

Cadillac uses a small camera mounted on the steering column and infrared lights to track the driver's head position when Super Cruise is turned on. If the system detects the driver has spent too long looking away from the road, it will gently remind them to start focusing on the road again using audio, a light bar on the steering wheel and animations in the instrument binnacle. Should the driver fail to respond, the car will pull to the side of the highway and call emergency services.

Cadillac will be slotting Super Cruise into the 2018 CT6, set to go one sale in Northern Hemisphere Fall.

Source: Cadillac

