Google has just released a new update on its self-driving car initiative, and the company has made a good deal of progress on the road over the summer. So far, Google's fleet of self-driving cars (about a dozen of which are on the road at any one time) have now logged more than 300,000 miles of test drives without a single accident in a "wide variety of traffic conditions." That's up from the 200,000 miles Google reported back in late April. It's a significant milestone — many more miles than the average car's lifespan — but still only represents a fraction of the testing that'll be needed before these cars are publicly available.

Google previously said it'll be driving "millions" of miles before self-driving cars are on sale, and the company also noted that it needs to test in many more driving situations as well. Google specifically mentioned snow-covered roadways and navigating temporary construction signals, but there's surely quite a few more challenges it'll need to work out before you can just sit back and enjoy the ride. Still, there's another milestone close at hand besides hitting 300,000 miles — testers will soon be using the cars solo (instead of in pairs) for driving to work, something Google says will bring this technology one step closer to every commuter."