GM's Cadillac division has reported they plan to release a "super cruise" feature in models mid-decade.

In the Cadillac video below, they explain the system as a combination of ACC, lane-keeping and GPS. This is similar to the other announced plans from many other car companies, including Mercedes, BMW, VW/Audi and others. The use of GPS suggests the car may also use map information, which is not known to be used by the other announced products, but is heavily used by Google and the various eyes-free projects.

It is pure speculation, but perhaps they are building maps of where the lane markers are reliable enough and where they have faded out so that they can refuse to super-cruise when approaching those zones. They might also use the GPS to assure you super-cruise only on the highway or other limited areas.

In the video, which shows a demo at about the 1:10 mark, they are driving on a test track, and always next to a blue line along the lane markers. Obviously a real product could not depend on special lane striping if it wants to be broadly usable, but this may assist them in testing their system with confidence. (ie. compare what their lane-finder detects to what an independent system that tracks the blue line detects.)

GM has had various self-driving projects, including the futuristic EN-V and the sponsorship of BOSS in the Darpa Urban Challenge. The Cadillac brand is well positioned. Self-driving is initially going to be a luxury feature, but companies that sell sporty performance cars don't want to detract from their image as selling a fun driving experience. A pure luxury brand like Cadillac does not have as much of that problem as BMW and Mercedes have. At the same time, the video insists that they don't want to take away from driving.