Lots of companies are working on self-driving car technology, and whoever gets there first will be positioned to make billions. But as the recent fatal accident in Arizona involving an Uber autonomous vehicle made clear, the technology is still faulty. One of the things that needs to get a lot better is how cars take in and respond to the world around them. Part of that is learning how to navigate back roads, where every bump and pothole hasn't been intricately mapped. MIT's Daniela Rus has research out today to help solve the problem — she talks about it with Marketplace's Amy Scott.