A national group estimates that the Memorial Day holiday weekend will be the third busiest for road travel since 2000.
The case is the latest dispute in the US about what kind of cultural attire is allowed at commencement ceremonies.
Carriers hope to meet demand for the busiest and most profitable time of the year and avoid the chaos of the last two summers.
The National Oceanic and Atmospheric Administration predicts 12 to 17 named storms, of which five to nine are expected to become hurricanes between June 1 and November 30.