While walking around our neighborhood my wife and I noticed a coach house; not an uncommon sight in Chicago. Coach houses no longer provide shelter for horses and carriages and have mostly been renovated into either garages or living spaces, but it brought up an interesting question. What other physical objects or parts of our environment are obsolete but have been repurposed because of their embodied cost, and what other objects do we commonly see today that will be obsolete soon but are expensive or permanent enough that they will need to be repurposed?
Being an (intern) architect the obvious answer is buildings. They're the most expensive thing, very permanent, and get repurposed continually but that's been going on since buildings have been built. The most recent widely adopted answer is smart phones. They have largely replaced calculators, GPS, maps, watches, address books, social interaction, etc. They've also created things that most of us couldn't have imagined just a decade ago, but none of these tangible items are objects of any significant permanence - old GPS units aren't going to be crowding us out of urban centers. My answer is parking lots.
It's always bothered me (oh the things that trouble me) that vast amounts of capital sits idle for much of its useful life. If we could put it to use more often it would raise the quality of life for all of us. The majority of cars sit idle 20-something hours a day, most people's homes are empty while they're at work or on vacation, offices (outside of architecture anyways) are empty at night, my computer doesn't run at full load continuously, most of the tools I own go unused 99% of the time - the list goes on. Cue the sharing economy.
People can rent out parts of their homes, Uber and Lyft make use of idle vehicles, zip car does it with a different business model, and cloud computing places processing burden on machines that run near full capacity continuously. There will always be inefficiencies, but the gain of even a few percentage points can free up billions of dollars worth of wealth to the benefit of all - assuming the powers that be don't hoard it all for themselves; that's another question though.
I think we can safely say that autonomous cars will soon be a reality. Tesla just released a car that has impressive autonomous features and the self driving Google cars keep getting better. This combined with the quick adoption of Uber seems to spell out a clear endgame. I have no idea when, but at some point in the not so distant future few if any of us will own cars. They'll be autonomous; rented, borrowed, or subscribed to; we will get places quicker; car accidents will be greatly reduced; roads will change; traffic will largely cease to exist; car insurance premiums will decline; police departments will have to find a new source of revenue; and parking lots will stop being built because cars won't need to sit idly (sort of, they'll need a place to charge at 3AM).
This will free up valuable real estate in urban areas, but how this could affect the suburbs is less clear. Certain typologies like strip malls and shopping centers rely on parking to create a sort of interstitial border. The mat to the artwork if you will (don't take that analogy too far). You can't just place infill there as it'd obscure the duck (branding of the businesses that occupy the buildings).
The whole situation is a reminder that our built environment is a reflection of our current level of technology. Advances like smart phones and the internet often get dismissed as some novel curiosity, but the reality is that such technology can be transformative. In this case some mostly intangible items like clever programming, sensors, and machine learning (to greatly oversimplify) will replace thousands of square miles of physical asphalt and concrete. It will reduce water runoff caused by hardscapes, the urban heat island effect will be reduced, the load on sewage treatment plants will be reduced in areas with a combined sewer system, urban areas can become more dense which means shorter commutes, and in turn a virtuous cycle of energy reduction will begin as less energy is needed for all the aforementioned activities. That and less parking lots. No one likes parking lots.