Book excerpt: Ongoing and emerging shifts in customer ground access behavior, resulting from the growing use of transportation network companies (TNCs) and the eventual adoption of emerging technologies, are posing a significant challenge to the reliance of airports on parking revenue. The TRB Airport Cooperative Research Program's ACRP Research Report 225: Rethinking Airport Parking Facilities to Protect and Enhance Non-Aeronautical Revenues is a guidance document that identifies near-term and long-term solutions to help airports of all types and sizes repurpose, renovate, or redevelop their parking facilities to address the loss of revenue from airport parking and other ground transportation services.