how safe are autonomous cars?

Do you want to find the exact answer to your question? Then you will find it helpful to read the article Top 5 Autonomous Cars Safety Features to Stay Alive https://www.intellias.com/top-5-features-to-ensure-you-re-still-alive-after-riding-in-autonomous-car/ . From myself, I want to add that the main explanation for the higher accident rate: autonomous cars drive clearly according to the rules, and in a critical situation on the road, where a deviation from those is required due to the fault of other road users, they cannot prevent an accident.