back of a spreadsheet; back of the net

I’m fascinated at the moment by two particular technologies and their impacts on the economy and on how we live. 3D Printers and Electric Self-Driving Cars. This post is about a potential second order effect of the widespread adoption of electric self-driving cars; what happens to all the car parks?

There are thousands of car parks in the UK. NCP alone have over 700 with spaces for some 200,000 cars. Most supermarkets have a car park. Most shopping malls have a car park. Factories, out of town offices and retail centres, railway stations, airports and sports grounds have car parks.  With 17 millions cars on Britain’s roads they have to be parked somewhere. In fact, they have to be parked in more than one place; near where we live and near where we are going to visit.

Self-driving cars mean fewer car parks.  Firstly, I think there will be fewer cars.  I think self-driving cars in cities will function more like taxis or car clubs than privately owned vehicles. (1)  With no driver to pay it makes more sense for more people to rent a car for a trip or by the hour than to own one out right.  So the absolute number of cars probably falls. These are cars that don’t have to be parked anywhere.  Secondly, as people’s usage of the car changes they need to be parked near destinations less often.

As an example I offer up a trip to the supermarket. Currently a trip to the supermarke involves driving to the supermarket, parking the car in the car park for an hour of so, and then driving the same vehicle home. If cars operate more like taxis there’s no need to park the car at the supermarket. You take one self-driving car to the supermarket. (2)  Do your shopping. Take a second, different self-driving car home. Or take the car that dropped you off once it has finished its next job. In the hour you are inside the self-driving car you came in could complete 4 return journey of 2 miles. (3)

Now, you may think “I don’t want to take a taxi to Sainsbury’s.”  All well and good but the land that Sainsbury’s lets you park on is worth cash money to Sainsbury’s. Given a choice between having you park there and having you take a self-driving car Sainsbury’s will want you to take the self-driving car. They would rather operate a taxi rank at the front of their building and sell the land.

With fewer cars needing to be parked less often there appears to be a long term over supply of car parking spaces. There are already just about enough car parking spaces in domestic streets and garages to house all the cars we own. If we’re not parking when we go shopping do we need all those car parks.

I’m assuming that the car parking spaces to be liquidated are those which are a) most easy to sell b) those furthest from where the car is going to start its duties in the morning. So the large car parks of out of town retailers will be those that are liquidated.

So what happens to the land?

Presumably the land holders will sell it for the best price they can get for it. It’s worth less and less to them as a car park.

So a stream of realatively easy to redevelop brown field sites become available for housing.

Two follow up questions occur to me.

What happens to out of town or suburban shopping centres when the value of the subsidised parking they offer to their customers is reduced because customers don’t need to park to shop any more?

What happens to council income from charging for car parking?

(1) and I think the cost structure looks something like 31 pence per mile for a standard drive yourself car, 11-18 pence per mile for a self-driving car and £2-3 per mile for a driven taxi cab. I think self-driving cars are half to 1/3^rd the cost of owning and driving yourself and tens of times cheaper than a traditional taxi.

(2) You might of course walk to the supermarket and then ride in a self-driving car home.

(3) At 20 mph urban driving speed 4 return journeys of 2 miles is 2*2*4 = 16 miles plus loading and unloading time. At a charge of 25 pence per mile this would yield revenue of £4, and a profit of about £1. £1 more than the car would generate sitting in Sainsbury’s car park.