Because of "Urban Sprawl", land has become a premium in suburbs that were once deemed rural. Over the past decade, parking lots have become an opportunity to maximize land use. In some cases, they have become green projects. These parking lots have been made into parks, condominiums with artificial wetlands to stop runoff, and in some cases, solar power generators.
But where do these parking spots go? Many times these parking spots are simply placed underground or in multilevel garages eliminating the need for the traditional parking lot and optimizing land use. Parking lots are seeing a change from level plains of asphalt to more efficient, greener structures that allow for land to be used efficiently.
Here is a great article from Time Magazine that tells more about the suburban parking lot change to combat urban sprawl. This is just another example of the type of thinking it will take to create an efficient, sustainable world (a lower need for parking spots would be nice too :)).