However, I've long thought that motor vehicles should have some kind of black box that monitors various driving metrics such as how "smooth" the driving is. This could provide valuable data to insurance companies and they should provide a sizable discount for drivers who agree to provide that data and have good driving scores.
There's also another benefit to measuring acceleration/deceleration data and that is to highlight if someone's faculties suddenly decline (e.g. illness or old age). Typically, when someone has failing eyesight, they might not be able to predict other vehicles as well and that would lead to more aggressive braking which can easily be measured. This could provide an important early warning system to the drivers that their driving has suddenly worsened and they might want to see a doctor unless they have a known temporary condition (e.g. hay fever).
Also, if the aim is to detect drink-driving, then that's easy enough to do from outside the vehicle with CCTV cameras and the police already have methods to stop drunk drivers. I suspect that the aim is surveillance rather than law enforcement.