I’ve had the role of accessing databases for large auto insurance companies. (Don’t believe everything the PR department tells you.)
ABS brakes, seatbelts and DUI enforcement all came into high visibility in the 90s. ABS brakes and seat belts were phased in by vehicle make and model. The same driver could be compared with the old model and the new model. Millions of drivers could be compared to get statistical data.
The benefit of ABS brakes was so dramatic it could not be missed. It could be demonstrated both anecdotally and statistically to reduce deaths in the thousands; and of interest to insurance companies, to reduce damage to vehicles in the millions (if not billions) and of interest to consumers, to reduce fender benders and most importantly to avoid a crash at all. Consumers saved hundreds of millions in deductibles and in depreciation on their cars.
The same type of analysis was applied to seat belts. But with seatbelts other factors came into play. The laws were phased in with some states having more aggressive laws than other states. At first seatbelts were voluntary. When most people didn’t buckle up, idiot lights and buzzers were installed. Then, for a while, the belts buckled you up automatically. Then states made buckle up mandatory. Of course, with each of these steps of increasing government mandate, the states only did it because federal highway transportation money was tied to it.
Enforcement was (and is) notoriously uneven. Enforcement is most stringent when the Feds provide extra money to enforce it. States that value personal freedom enforce it less than states have no regard for personal freedom.
Thus Bernie Sanders Vermont and Massachucetts historically have the weakest seat belt laws and weakest enforcement...and also the lowest rates of car crashes of any state. Red states that value personal freedom are next lowest. Anti-freedom states are at the other end.
But there are other factors. There are more police in high crime areas and those police are looking for an excuse to pull someone over because he “looks suspicious”. So there are more seat belt violations in high crime areas.
A whole list of other factors is too long for this post. But be it said that my SQL compared virtually every column on dozens of tables looking for a correlation any which way and could only find correlatons so weak that they would be laughed at in a statistics class.
The only way to find a correlation is to start with a pre-conceived conclusion and then only select (cherry pick) the data that proves that conclusion. (Sort of like the climate-change people do.)
By the way, in looking ad auto and homeowner and life insurance data there is one correlation that jumps out and has no competitor even close.
ALCOHOL (add drugs if you wish. and my statements are pre texting while driving.)
Alcohol is the single strongest correlation with vehicle tragedies, and with tragedies in the home and with tragedies with guns and tragedies with knives and with domestic violence and boating/swimming tragedies and snowmobile and RV tragedies.
People do stupid things when they’ve had alcohol. A little alcohol increases the tragedy rate well above the non-alcohol rate. A lot of alcohol puts the correlation off the chart.
Prior to working on databases, my career was loss prevention and safety consultant for the same big P&C Insurance Companies, mostly in Illinois from Galena to Zion to Cairo. But most of it was in the Chicago inner city which had the population and where I lived. I was good at it. But preventing losses didn’t pay anywhere as good as IT. So I switched careers.