The EU funded SARTRE project (Safe Road-Trains for the Environment) is working to develop what is called vehicle platooning. This means that only the first vehicle has a driver. Developers hope that the idea will improve safety, efficiency and mileage, will reduce journey times, road congestion and pollution from cars. Various surveys have shown that 90% of accidents are due to boredom while driving on motorways, but with SARTRE a car can drive itself up the motorway.
The idea has been around for a long time, maybe over 20 years, and there has been many attempts at it. Maybe this time it's the right attempt. After all the technology has matured a lot, and latest legal developments with the Google car make autonomous vehicles seem more realistic.