The land value data comes straight from New York City public data from the assessor's office. The parking lots are automatically identified using freely available public satellite imagery data paired with commodity computer vision algorithms we found on hugging face.
Not only does New York City have some of the most valuable real estate in the world, a lot of it is just sitting there as low value uses. This visualization makes it much easier to find and quantify this.
There is an open source version of civic mapper that includes the 3D visualization feature we showed before, but we have not yet released the parking lot identifier. The open source version is at www.putitonamap.com #education source