The state legislature of state A enacted legislation prohibiting the use of tractor-trailer rigs weighing more than 100,000 pounds gross, on the basis that superheavy trucks rapidly degrade the state's roadways and pose a greater safety danger than smaller trucks. A trucking firm that frequently uses state A's highways for trips between state B and state C purchased several tractor-trailer rigs weighing over 100,000 pounds when loaded. The trucking firm brings an action for declaratory relief in federal court in state B, seeking to have the state A legislation declared unconstitutional. It presents expert testimony that the heavier trucks are no less safe than smaller models. State A produces no evidence, but asserts that the legislation is justified as an exercise of its police power.
How should the trial court rule?