I'd prefer something with a slightly more libertarian bent:
The hardware is required in new cars. It's illegal to make it report false values or for someone other than the driver to record. When you press the start button, an LED shines into your skin and records fingerprint hash, and blood alcohol. This data is recorded/reported only when a public road has been entered or crossed, and erased from local storage in 24 hours.
The reporting is optional. You can turn it off. You set it up to report to your insurance company. If you don't, your insurance rates will probably rise.
What does society get out of this? People are strongly encouraged not to drink and drive. They get a clear and unambiguous signal if they are over the legal limit or not. We get some insurance data about how many people are drinking and driving nonetheless, and their actual accident rates. Insurance rates can be higher for people at higher risk, and lower for those who are not. There's no emergency situation where someone can't activate their car. Drivers' "freedom" to drive without insurance or without historical monitoring isn't infringed. You can still drive drunk on private property without consequence.
We could probably also partially do away with constructive DUI (DUI where you are drunk, but asleep in the vehicle and in possession of the keys). You can set a maximum startup BAC in the car computer. You can lower it, effective in 8 hours. Your sober self can agree that future you shouldn't drive drunk, and even if you sleep in your car, the police can't show that you were in control of the vehicle.
I wouldn't describe myself as libertarian. To make a libertarian strawman, such a strawman might claim that all safety features in cars ought to be provided by the free market. Of course, the predictable outcome is that most people won't prioritize safety in cars, so cars that spend their production budget on non-safety features will outsell those that spend on safety features, leading to at best a niche market for safety cars.
So no, I don't think any libertarian is OK with being forced to do almost anything, in principle. The very idea that you'd need to wear seatbelts or have a license or be compelled to have insurance or not have an open bottle of vodka in your cup holder is anathema. The free market should simply operate through the courts and put those that can't drink responsibly and cover the damage they cause into debtors prisons, to continue the strawman.
I would actually prefer much stricter enforcement of insurance and licensing laws, akin to say, the UK or Germany. I don't think you need hardware interlocks to do it, but you would have to have police willing to actually pull over people with fake license plates or missing insurance. That is not the case in much of California.
The hardware is required in new cars. It's illegal to make it report false values or for someone other than the driver to record. When you press the start button, an LED shines into your skin and records fingerprint hash, and blood alcohol. This data is recorded/reported only when a public road has been entered or crossed, and erased from local storage in 24 hours.
The reporting is optional. You can turn it off. You set it up to report to your insurance company. If you don't, your insurance rates will probably rise.
What does society get out of this? People are strongly encouraged not to drink and drive. They get a clear and unambiguous signal if they are over the legal limit or not. We get some insurance data about how many people are drinking and driving nonetheless, and their actual accident rates. Insurance rates can be higher for people at higher risk, and lower for those who are not. There's no emergency situation where someone can't activate their car. Drivers' "freedom" to drive without insurance or without historical monitoring isn't infringed. You can still drive drunk on private property without consequence.
We could probably also partially do away with constructive DUI (DUI where you are drunk, but asleep in the vehicle and in possession of the keys). You can set a maximum startup BAC in the car computer. You can lower it, effective in 8 hours. Your sober self can agree that future you shouldn't drive drunk, and even if you sleep in your car, the police can't show that you were in control of the vehicle.