Will self-driving cars ever be safe to hit the roads? Report claims the vehicles would need to drive 'billions of miles over hundreds of years' to be fully tested

Autonomous vehicles would have to be driven hundreds of billions of miles to create enough data to clearly demonstrate their safety, according to a new report. Under even the most-aggressive tests, it would take existing fleets of autonomous vehicles hundreds of years to log sufficient miles to adequately assess their safety compared to human-driven vehicles. Researchers say the findings suggest that in order to advance autonomous vehicles into daily use, alternative testing methods must be developed to supplement on-the-road testing. Autonomous vehicles (Google's car pictured) would have to be driven hundreds of billions of miles to create enough data to clearly demonstrate their safety, according to a new report. The report, Driving to Safety: How Many Miles of Driving Would It Take to Demonstrate Autonomous Vehicle Reliability?, was written by Rand Corporation.