According to Sky News:
Self-driving cars are generally safer than cars driven by humans, according to a new study released on Tuesday. However, the cars were found to be more accident-prone in certain scenarios.
- at dawn
- at dusk
- during the day and at night
- when turning and going straight
- when starting and stopping
- when they don't have an internet connection
- when they don't have a driver
Otherwise self-driving cars are prefectly safe.