Google's self-driving cars tear up 3 million miles a day - CNET

Google's autonomous cars drive millions of miles each day along virtual roads.

In its self-driving car report for January, Google notes that actual road testing is a vital but that simulation plays an equally important role. Each time Google improves or refines a key feature in the technology, it tests that feature in a virtual environment using thousands of variations.

As a result, Google's vehicles drive a simulated 3 million miles each day. "That's the equivalent of circling the equator five times every hour," the company said.

The report offers a glimpse of how Google is using simulation to replicate real-world driving. The virtual tests are necessary to prevent real-life problems and to assuage conces that have cropped up amid increased interest in the technology.

As one example cited in the report, Google wanted to make left tus at intersections more comfortable for passengers, so the company tweaked its software to adjust the angle of the tu. To test this change, the company repeated its history of more than 2 million miles with the new tuing patte to ensure that the modification actually improved left tus and people's experiences in the cars.