The self-driving software firm Embark Trucks said Wednesday it plans to go public in a deal that would raise more than $600 million and value the company at more than $5 billion. Alphabet’s Waymo just raised $2.5 billion in fresh funding as it tries to expand its self-driving taxi fleet outside of Phoenix. Chris Gerdes is a professor of mechanical engineering and co-director of the Center for Automotive Research at Stanford and a safety adviser with Ford’s autonomous-vehicle division. Marketplace’s Amy Scott asked him where all this money is going.