Structured Parking, a Stranded Asset?

Ryan Falconer of Arup posted some interesting thoughts about how automated vehicles (AVs) will change the parking that serves airports and train stations. My mind immediately turned to structured parking.

Due to both zoning mandates and client level-of-service concerns, projects that aim for anything approaching an urban level of density generally include a parking structure. The two most common forms in the recent housing expansion seem to be the sub-grade garage that serves a tower and the mid-rise pre-cast garage that is wrapped in wood-framed apartments.

If the coming of the AV does indeed radically reduce the need for static parking, purpose-built parking structures run the risk of becoming, if not stranded assets, non-performing ones. Only those garages that serve ultra-premium properties are designed to anything significantly above code minimums for floor-to-floor height. Smaller garages generally slope the floor plates rather than have dedicated ramps. While cars are heavy, they are also large, meaning the structural loads are actually quite a bit lighter than those for general office or storage uses. That combination of low height, sloping floors, and light loading means that these structures will be very difficult, if not impossible, to adapt to other productive uses.

Structured parking is often seen as a necessary evil, but how much darker is it to have such a large, unnecessary evil?