Heathrow Airport's autonomous cars (photos)

Autonomous cars aren't the future--they're already here and in use in London. Heathrow Airport swapped two diesel buses for 22 electric pods that shuttle passengers from Terminal 5 to the parking lot without the help of a driver.

Each electric pod can carry up to four passengers and their luggage.

At the terminal, passengers request a pod and enter their destination to tell the pod where they want to go.

In the pod, passengers don't have to worry about traffic or the pod's ability to navigate around cars because they travel on designated roadways, and it takes about 5-6 minutes to travel approximately 1.2 miles to the T5 Business Car Park.

The autonomous vehicles, made by Ultra PRT, have yet to be in an accident, according to an article in The New York Times.

They operate at a top speed of around 25 mph, and can handle light snow.

Because the electric vehicles operate only when needed, they're more energy-efficient than the pair of diesel buses that formerly looped the airport, stopping at every drop-off point regardless of the passenger load.