Moscow is a terrifying city for drivers. So what if a car doesn't have one?

Chaotic roads, bad weather and reckless habits make the Russian capital one of the worst to drive, and its quest to build an autonomous car uniquely challenging

In certain sunny climes, self-driving cars are multiplying. Dressed in signature spinning sensors, the vehicles putter along roads in California, Arizona and Nevada, hoovering up data that will one day make them smart enough to run without humans.

Besides perennial sunshine, those places share other common traits: wide, well-manicured roads, functional traffic enforcement, and agreeable local governments. That's how Chandler, Arizona - a Phoenix suburb on nobody's radar as of a few weeks ago - became the first US town to host autonomous cars on public streets without human safety drivers. Courtesy of Waymo, they're expected to start carrying passengers within the next few months.