Until ALL vehicles on the road are autonomous and there are external monitors to assist (i.e. receiving info from sensors in the road, nearby, etc) there will always be a significant risk when using autonomous vehicles. Maybe at some point, self-driving vehicles will be prohibited on the major interstates where there would be a very low risk of incidents. However, I think anything like that is even remotely likely in the next 25 years. There are people still driving around in cars without seatbelts or airbags. Hell, people drive around with parts and shit hanging off their shitbox cars. It'll be a long time before the vast majority of people have self-driving vehicles and even then, they need to maintain them properly. If sensors aren't working properly, software is out of date, etc. it will cause issues.