We humans are often the most dangerous part of an automobile. That's why scientists have been working on automated highway technology for decades. In the 1990s, the U.S. Department of Transportation sponsored the National Automated Highway System Consortium (NAHSC), which successfully demonstrated the potential of radar, magnetic and visual sensors that allowed test vehicles to navigate a specially prepared length of highway. The U.S. Defense Advanced Research Projects Agency (DARPA) also underwrote an autonomous vehicle research and development program, culminating in its 2007 Urban Challenge.
But this is one future invention that we're probably going to see sooner rather than later. Since the mid-2000s, Google scientists and engineers have been working to develop autonomous vehicles that use artificial intelligence software and Google Maps to navigate. Testing of driverless cars on public roads actually has been approved in Nevada, Florida and California [source: Gudipaty]. In fact, Google says that about dozen self-driving cars are on the road at any given time, and they've travelled 500,000 miles (804,672 kilometers) in beta tests [source: Fisher].
Google still awaits federal and state regulatory approval to engage in more extensive tests, and it's still unclear when -- or rather, if -- ordinary folks will be able to buy a car that drives itself [source: Crawford]. But there's talk that Google is set to build its own driverless car [source: Worstal]. Electric car company Tesla also is throwing its driving cap into the race, claiming it can have a car that does 90 percent of the work by 2016 [source: Carroll].