When can consumers buy a Google driverless car? And why would they?

    Google's (GOOG) dramatic experiments on California roads with driverless-vehicle technology, publicized with mild fanfare within the past week, could legitimize a once far-fetched concept for personal transportation.

    The general public hasn't closely followed breakthroughs in artificial intelligence and digital control systems as they apply to so-called autonomous vehicles. But the military's drone aircraft, which can take off, land and carry out military missions by remote control may provide some hints as to how far driverless cars can go. Achievements in the automotive realm have been made partly by university scientists who receiving funding from the U.S. Department of Defense's research and development arm, DARPA, as well as by automakers.

    Thanks to the the financial resources and creativity of Google, driverless technology is moving toward mass-market application sooner than anyone predicted, in the same manner that Internet technology migrated from university laboratories to personal computers once it was embraced by companies like Aol (AOL).

Why it took Google to build a working driverless car

    What Google brings to the table is an outsider's perspective and an understanding of tech-savvy consumers. Automakers have long known that cars could be built to drive themselves, but have been cautious about overselling the idea to the public or predicting their imminent arrival. In the meantime, automakers have developed a raft of features to mitigate driver distraction, which ultimately could be used to take driving out of human hands.

    "The industry knows the long road that has to be traveled to make driverless technology successful,'' said Tom Kowaleski, a spokesman for BMW's U.S. operations.

    Safety and litigation worries by the industry have previously slowed the introduction of features now considered basic, such as airbags. Conventional wisdom has held that no machine could process as much information as a driver or react as well – but the time may have finally come where perhaps the opposite is true. "Every new piece of technology we introduce takes three to five years of gestation before it can be introduced. I have no crystal ball," Kowaleski said.

    While Google's latest experimental vehicle uses sensors to see its surroundings and respond appropriately, BMW, Toyota and other automakers have been experimenting with a different kind of technology: Their experiments revolve around communication systems that allow cars to exchange wireless signals. A car that encounters a slippery road, for example, could inform others approaching the area, Kowaleski said. In an early stage of the technology, the driver could respond to a warning; eventually cars could be taught to respond on their own by slowing down or engaging all wheel drive or some other feature.

    Toyota was the first automaker to offer a feature that allowed a driver to overcome the difficulty of parallel parking by letting the car do so on its own. John Hanson, a Toyota spokesman, said in an emailed message that the automaker has been working on autonomous vehicles and related technologies and "will be a leader'' when such vehicles are introduced.

    Beyond the technological hurdles, which seem less difficult to surmount as companies like Google weigh in, automakers may have to consider a different model for personal transportation once a human driver is no longer essential. Here's where the technology might both empower consumers and startle car makers.

    Cars that don't need drivers also may not need private owners – since they could be summoned remotely and returned once their journey is complete. Why take on a lease if you can purchase a subscription to a car instead? Netflix (NFLX) has already soundly proven that consumers will change their habits if enough of an incentive is provided. Car owners who never want to spend a Saturday under the hood or in the waiting room of a mechanic's shop again might quickly adapt to a car subscription model.

    With Google's driverless leap forward, both in terms of technology and in presentation to an increasingly tech-savvy and tech-obsessed world, the joys of car driving and car ownership may give way to the convenience of forgoing the gasoline pump -- or the charging station -- for good.