From 2012 to 2019, the Volpe Center assisted the National Park Service (NPS) Alternative Transportation Program with understanding the role and impact of transit in the parks by producing the National Transit Inventory and Performance Report. These annual inventories track the annual operational performance of NPS transit systems, and present ridership, operational characteristics, and environmental impact information collected from roughly 100 transit systems operated in more than 60 national parks across the United States. This reporting helps NPS preserve park environmental resources while enhancing access to these national natural treasures.

Key findings from the 2019 inventory include:

• 95 transit systems operated in 60 of the 421 National Park Service units.
• Total passenger boardings across all systems were 45.9 million.
• NPS owned and operated 21 of the 95 systems.
• NPS transit vehicles have an estimated $139.3 million in recapitalization needs between 2019 and 2031.