What they are up to.

They have self-driven over 1 million miles and are currently out on the streets of Mountain View, CA, Austin, TX and Kirkland, WA. Their testing fleet includes both modified Lexus SUVs and new prototype vehicles that are designed from the ground up to be fully self-driving. There are safety drivers aboard all vehicles for now. They look forward to learn how the community perceives and interacts with the cars, and uncovering situations that are unique to a fully self-driving vehicle.

Why self-driving cars matter

Imagine if everyone could get around easily and safely, regardless of their ability to drive.Aging or visually impaired loved ones wouldn't have to give up their independence. Time spent commuting could be time spent doing what you want to do. Deaths from traffic accidents—over 1.2 million worldwide every year—could be reduced dramatically, especially since 94% of accidents in the U.S. involve human error.

How it works.

The self-driving cars are designed to navigate safely through city streets.They have sensors designed to detect objects as far as two football fields away in all directions, including pedestrians, cyclists and vehicles—or even fluttering plastic shopping bags and rogue birds. The software processes all the information to help the car safely navigate the road without getting tired or distracted.

Recently one of their cars hit a bus during the run. “We don’t like our car bumping into things,” said Chris Urmson, head of Google’s self-driving project, addressing the February 14 incident where Google’s car struck a bus. “This was a tough day for us.”

During a talk at SXSW, Urmson shared images from the Valentine’s Day bump—“bumping” is probably the best possible way to describe it; the vehicle was going 2 mph—and talked about what Google learned from the incident.

Google’s cars have far more experience than any human on the planet—the fleet is driving as many miles in a single day as a typical American drives in a year. And as we know, the cars are also adding features all the time to help them learn how to drive more like humans. In fact, Google had recently implemented a capability for its cars to hug the shoulder a bit on Mountain View’s extra-wide right-hand lanes, allowing it to behave a little more like its fellow drivers might. It’s the same reasoning that allows a Google car to break the law to cross a yellow line to get around an improperly parked car, for example.