While no car can prevent all accidents, we work every day to make them less likely to occur. The massive amount of real-world data gathered from our cars’ eight cameras, 12 ultrasonic sensors, and forward-facing radar, coupled with billions of miles of inputs from real drivers, helps us better understand the patterns to watch out for in the moments before a crash.

As our quarterly safety reports have shown, drivers using Autopilot register fewer accidents per mile than those driving without it. That’s because Autopilot is designed to reduce fatigue by helping drivers stay in their lane, while also ensuring that they keep their hands on the wheel. While lane-keeping and hands-on monitoring can be extremely effective at helping to reduce the likelihood of an accident when Autopilot is in use, we believe that these precautions can also be extremely effective for preventing accidents when Autopilot is not in use.

Source: https://www.tesla.com/blog/more-advanced-safety-tesla-owners