What are the weakest links in the autonomous driving chain?

The US is jockeying for a leadership position in autonomous vehicles (AVs), both for the safety and the economic benefits they could bring. While the Department of Transportation (DoT) has been supporting efforts in the form of guidance documents, proposed rulemaking and grants, automakers and suppliers are busy developing and testing new technology. Today, AVs are undergoing road tests in more than 34 US states, as well as numerous closed facilities. The University of Michigan's MCity is one of the largest of these.