What are the Autonomous Driving Levels?

Some of the first concepts for self-driving cars date back to the 1920s. However, it wasn't until recently that the idea of consumer self-driving cars began to near reality. As the technology for self-driving cars has become more feasible at scale, the need for regulation has grown along with it. With all of the buzz around autonomous or self-driving vehicles in the news, you may be wondering, "What are the autonomous driving levels"? Back in 2013, the US Department of Transportation's National Highway Traffic Safety Administration (NHTSA) came up with a set of five levels (well, six including level 0) to characterize the classes of self-driving cars and their capabilities.