If your trade, traffic, or transportation is one of the following, this is considered interstate commerce. Source: 49 CFR 390.5.:
Between a place in a state and a place outside of such state (including a place outside of the United States)
Between two places in a state through another state or a place outside of the United States
Between two places in a state as part of trade, traffic, or transportation originating or terminating outside the state or the United States
U.S. DEPARTMENT OF TRANSPORTATION Federal Motor Carrier Safety Administration, 2014 December 12th https://ask.fmcsa.dot.gov/app/answers/detail/a_id/249/~/what-is-the-difference-between-interstate-commerce-and-intrastate-commerce%3F