In American Trucking Assns., Inc. v. Michigan Pub. Serv. Comm'n (2005) 545 U.S. 429, Michigan imposed a flat $ 100 annual fee upon trucks engaging in intrastate commercial hauling (undertaking point-to-point hauls between Michigan cities). (American Trucking, supra, 545 U.S. at p. 431.) The petitioners challenged the fee on the ground that it discriminated against interstate carriers and unconstitutionally burdened interstate trade, because the fee was flat but trucks carrying both interstate and intrastate loads engaged in less intrastate business than trucks carrying only intrastate loads. (Id. at pp. 431-432.) The United States Supreme Court held that the fee did not violate the dormant Commerce Clause, because it was imposed upon only activities taking place exclusively within the state's borders, did not facially discriminate against interstate or out-of-state activities or enterprises, and applied evenhandedly to all carriers making domestic journeys. (545 U.S. at p. 434.) In addition, there was little if any evidence that the fee imposed any significant practical burden upon interstate trade or unfairly discriminated against interstate truckers. (Id. at pp. 434-435.) In response to the petitioners' argument that the fee failed the internal consistency test, the court conceded that if every state imposed such a fee, an interstate trucker doing local business in multiple states would have had to pay hundreds or thousands of dollars in fees if it supplemented its interstate business by carrying local loads in many other states. The court nonetheless found no Commerce Clause violation, because it would have to incur such fees only because it engaged in local business in all those states. (545 U.S. at p. 438.) "An interstate firm with local outlets normally expects to pay local fees that are uniformly assessed upon all those who engage in local business, interstate and domestic firms alike." (Ibid.)