GM's first car with self-driving technology is likely to be a new top-of-the-line Cadillac sedan. Its styling is expected to resemble that of last year's Elmiraj concept car, shown here. Source: General Motors Company.

Are you ready for a Cadillac that drives itself -- at least sometimes?

It's coming. General Motors (GM -0.17%) CEO Mary Barra said at an event on Sunday that GM would put its "Super Cruise" system, which can drive a car automatically under limited circumstances, into production on an unspecified 2017 Cadillac model.

While it's still not quite a "self-driving car," GM's Super Cruise system will allow drivers to take their hands off the steering wheel and pedals under certain circumstances -- while the car drives itself.

Is the world ready for this? It doesn't matter: It's going to happen, because the competition has forced GM's hand.

A limited self-driving system that's coming very soon
"Super Cruise" is sort of a catchall name for GM's automated driving technology, and the system that reaches customers will likely evolve considerably over time.

But as its name suggests, the system that's expected to come to market in a couple of years is essentially a super-smart cruise control: At highway speeds, or in stop-and-go traffic, the system can take control of the car's steering, acceleration, and braking.

GM says that the first version of the Super Cruise system will be "designed to increase the comfort of an attentive driver on freeways, both in bumper-to-bumper traffic and on long road trips."

In other words, it's not all that different from the current "adaptive" cruise control systems that use radar to keep you at a set distance from other cars; it's just... smarter.

It's also -- and this is very relevant -- very similar to the new Mercedes-Benz "Intelligent Drive" system that Daimler (MBGA.F -0.69%) recently started offering on Mercedes' top-of-the-line S-Class sedans. 

Here's why GM is rushing Super Cruise to market
Most observers agree we're still years away from the arrival of mass-market cars that can drive themselves under any circumstances, or even most circumstances. 

Google's famous experiments and cute self-driving prototypes notwithstanding, there are a host of big problems that need to be solved before self-driving cars hit the market, starting with the need for a legal and regulatory framework to govern them.

Google's prototype self-driving car is cute and distinctive. But self-driving technology is much more likely to appear first in big luxury sedans. Source: Google. 

Like most of the big global automakers, GM has been working on aspects of self-driving technology for a while. And as we've seen at Ford, Toyota, and other automakers, some bits and pieces of that work have already come to market: Think blind-spot warnings, self-parking systems, and the aforementioned adaptive cruise control, among others.

But now, GM needs to get Super Cruise to market. Barra may not have been willing to say which Cadillac would get it first, but she didn't have to; it's an easy guess. 

It's well-known that GM is gearing up to launch a new top-of-the-line Cadillac sedan that will confront the Mercedes S-Class head-on -- and it's a safe bet that that new car will bring lots of new technologies to market, including the Super Cruise system.

A must-have to take on Mercedes-Benz and BMW
Traditionally, automakers have brought their latest innovations to top-of-the-line models first, and then gradually rolled them out on mass-market models as costs fell.

Innovations from the first automatic transmissions to the latest smart cruise controls have followed that pattern. And since technologies like lane-change warning systems have already begun to appear in mainstream sedans (and even some compact cars, like the upcoming 2015 Ford Focus), the pressure is rising on luxury-car makers to push the envelope even further.

The all-new 2014 Mercedes-Benz S-Class includes a system similar to GM's Super Cruise. Under very limited circumstances, the car can drive itself. Source: Mercedes-Benz.

Like GM, Daimler has been working on self-driving technologies for years. But that competitive pressure is why it chose to bring its first production system to market on the all-new S-Class that debuted last fall.

Right now, it's a big competitive advantage, and it's one reason global S-Class sales have more than doubled this year. Mercedes-Benz's archrivals, BMW and Volkswagen's Audi brand, don't have anything like it -- yet.

But it's a safe bet that they will, soon. And that means GM, which very much wants Cadillac to be seen as a global peer of BMW, Mercedes-Benz, and Audi, needs to have it in its upcoming new top-of-the-line model.