Try making a left turn in a state with sub-par signals without tripping the accelerometer threshold for a bad driver. This will punish good drivers forced to deal with bad civil engineering.
Or is it more accurate to say it gives them an incentive to address the bad civil engineering through their behavior.
The insurance company is operating on an actuarial table that shows cornering with those accelerometer values is statistically involved in more accidents. The user will slow down because now they're aware of the requirements to make a safer turn. That is a third order effect based on the insurance company adding more information to the driver's calculus.
The 'punisher' here is the design that forces you to choose between dangerous turns or slow navigation.
By the way, I guarantee their actuarial tables don't know whether you're creating high g forces in or out of control.
And now we've created a system that punishes the driver that brakes hard to avoid the tentative turner, who is incentivized to make the situation MORE dangerous by turning timidly.
I think it'd be pretty easy for sensors with a CPU to determine what's out of control. That tech is well developed and very stable, similar to how iOS can tell the difference between me walking and me shaking my phone.
Because they're not trying to reward you/punish someone else.
It's a risk mitigation tactic, despite what Progressive's commercials frame it as.