USDOT Secretary Sean Duffy visited Tesla's Gigafactory Texas and praised the company's contributions to U.S. innovation.During the visit, Duffy expressed the need for a national standard for autonomous vehicles in the United States.He discussed with Tesla CEO Elon Musk about the importance of a unified set of rules for autonomous driving across the country.Duffy mentioned that the USDOT is working towards developing a standard to ensure the safe and natural operation of self-driving cars nationwide.