Is uber safe for female riders?

Uber is safe for female riders, but there are always risks involved within this topic. Now Uber have taken a strong call on the safety of the riders. They have set some rules for drivers. Drivers have to be over 21, have criminal background checks from the police. It is compulsory to have an exemplary driving record. They have to have full insurance policies. So the trip can be safe and Uber can trust that driver before the hiring. But still issues are not sorted out in terms of safety. Travelling alone in Uber by a female driver is not safe in big cities. Uber take strong action against the drivers but it happens after the incident.