Indeed it is. The company behind Android is also making robot cars. Google announced in October of 2010 that they were testing self-driving cars on actual roads and highways in California. Google clarified that these cars were automated, but they always had a trained driver in the driver's seat and software engineer in the passenger seat as well as a traditionally driven scout car that drove ahead and mapped out the road conditions. However, a robot-driven car on actual roads is a pretty amazing piece of research, and just the idea of actual working robot cars makes me wish I could buy one right now. However, we're probably still many years off from seeing any actual self-driving car in the market.
Automated cars like this will likely find their way into public transportation before they become personal vehicles, but we may have our pizzas delivered by robot in the near future.
How do self-driving robot cars work? They use a combination of GPS, maps, cameras, and other sensors as well as the data from the scout car sent ahead of them. Perhaps future robot cars would also use data from cameras or sensors built into the roads, just as we visually use things like road signs and traffic alert systems.