Many of
Florida Atlantic University and Palm Beach State College's roads or parking lots throughout the campuses are former runways.
The site has a darker history; it was once part of the Yamato Colony, and was seized by "eminent domain". It then became an Army Air Corps' training facility, and part of it became Boca Raton's municipal airport. Training changed to another site, and the site went to a new public University. (FAU has made some amends with its past, and frequently donates to the nearby Morikami Museum.)
But yeah, it was possible to drive like a nut on some the campus roads and
still not get in anyone's way. There was never much of a battle for parking, either...local EMTs and helicopters used to train on some of the far-off runways. But there's been a lot of new construction over the last 20 years which eliminated a lot of the disused runways.