Rates for human drivers are currently at the correct level for insurance companies to pay for damage and make some profit.
If autonomous cars result in less damage than humans, their insurance price will be cheaper than human drivers, but there's no reason to raise the human rate at the same time, their accident rate should stay the same.
I don't think you're seeing the future trajectory. Autonomous cars and trucks will be able to do their thing with a much smaller margin for error - because they don't make errors. So for example instead of two seconds distance to the car in front of you it will be 0.1 second. The vast majority of humans would have an accident as soon as they got on the road.
We need that increase volume and reduced accident count in order to grow without having to build more roads.
> If autonomous cars result in less damage than humans, their insurance price will be cheaper than human drivers, but there's no reason to raise the human rate at the same time, their accident rate should stay the same.
Wouldn't the accident rate for humans go down as well as the percentage of SDV increase? After all, the humans won't be exclusively having accidents with each other.