American Car Rental Association v. Humphreys

On July 27, 2026, a divided Tenth Circuit panel affirmed a district court’s decision upholding Colorado’s $3-a-day “Congestion Activity Fee” on short-term vehicle rentals. The American Car Rental Association had challenged the fee as preempted by federal law, and WLF’s amicus brief urged reversal to restore Congress’s intent and to protect the free flow of air commerce. The Tenth Circuit’s majority held that Colorado’s congestion impact fee is not preempted by the Anti-Head Tax Act because the fee is imposed on consumers rather than on car-rental businesses at airports. Judge Eid dissented, arguing the fee is levied directly on airport car-rental businesses and is not generally imposed on sales or services, so it is preempted.