After years of anticipation, tech giants and car manufacturers alike are now testing autonomous vehicles on public roads around the world. As ambitious innovators race to develop what they see as the next high-tech pot of gold, some experts warn there are still daunting challenges ahead, including how to train artificial intelligence to be better and safer than humans at making life-and-death decisions. How do self-driving cars work? What must computers be capable of to truly take the wheel?
