President Donald Trump’s recent executive order saying truckers who don’t read and speak English proficiently would be considered unfit for service is causing ripples of concern within the industry.

U.S.-bound container import volume—at 2,217,675 TEU (Twenty-Foot Equivalent Units)—was up 1.8% compared to May and down 3.5% annually, following a 9.7% sequential decline from April to May and a 7.2% ...