The long term trend for national parks over the last 100 years has been increasingly upward: https://fivethirtyeight.com/features/the-national-parks-have-never-

The long term trend for national parks over the last 100 years has been increasingly upward: https://fivethirtyeight.com/features/the-national-parks-have-never-been-more-popular/ https://fivethirtyeight.com/features/the-national-parks-have... -- it seems like the only dips in visitation occur during times of economic depression or war. The most extensive survey I could find on outdoor activity (http://www.outdoorfoundation.org/pdf/ResearchParticipation2016Topline.pdf http://www.outdoorfoundation.org/pdf/ResearchParticipation20...) seems to indicate that, while popularity of individual activities varies, the participation rate seems to have been roughly the same overall for a decade, at least. Maybe hunting and camping will decline a little bit in importance, as it seems to be doing over the long term on this survey. But others might take its place. On this survey, it seems like day hiking, kayaking, BMX biking, and trail running / adventure racing made some significant gains over the last ten years, for instance. The main thing I can see autonomous cars doing is improving the park experience overall, by easing the traffic congestion in the most popular parks.