The Economist:

CARS that need no driver are just around the corner according to Google, which has been testing vehicles bristling with aerials and cameras on public roads in America. But Google does not make cars (yet), so it will be up to firms that do to bring the technology to market. And carmakers are a conservative bunch. Still, slowly and steadily the autonomous car will arrive, with the help of an increasing number of automated driving aids. Volvo recently demonstrated one such feature: a car that really does park itself.

Some cars already have systems that assist with parking, but these are not completely autonomous. They can identify an empty parallel-parking space and steer into it while the driver uses the brake. The Volvo system, however, lets the driver get out and use a smartphone application to instruct the vehicle to park. The car then trundles off, manoeuvres into a parking place and sends a message to the driver to inform him where it is. The driver can collect the car in person or use his phone to call it back to where he dropped it off. Autonomous parking could thus be provided at places like shopping centres and airports, which are controlled areas in which automated vehicles can be managed more easily than on open highways.

In the past, designs for doing this have relied on car parks being fitted with buried guide wires that a vehicle can follow to an empty bay. That, though, creates a chicken-and-egg problem: car-park operators will not invest in such infrastructure until there is a sufficient number of suitably equipped cars on the road. Drivers, conversely, will not want to buy self-parking cars if there is nowhere to use them.