The technology behind self-driving cars has advanced in recent years, but the vehicles still have a long way to go before becoming a common feature on the roads, said an executive from a a major Chinese automaker. Some of the hurdles impeding self-driving cars include legal restrictions, people's mobility habits, and technology that's still changing and maturing, Feng Xingya, president of Guangzhou Automobile Group or GAC, said on Monday at CNBC's East Tech West conference in the Nansha district of Guangzhou city, China. "A self-driving system is a developing concept," Feng said in Mandarin translated by CNBC. He added that the technology behind such vehicles are still being developed, with breakthroughs coming in batches.

In a few years, well-mannered, self-driving robotaxis will share the roads with reckless, law-breaking human drivers. The prospect is causing migraines for the people developing the robocars and is slowing their development.

Someday autonomous cars will have common sense programmed in so they will cross a double-yellow line when warranted or to speed up and find a gap to enter a freeway. Carnegie Mellon has taught its cars to handle the "Pittsburgh Left" by waiting a full second or longer for an intersection to clear before proceeding at a green light. Sensors also track crossing traffic and can figure out if a driver is going to stop for a sign or red light. Eventually there will be vehicle-to-vehicle communication to avoid crashes.