For some reason your site won't load.

Actually all accidents are darn close to 100% fault of someone, the question is who is at fault and why. Some people may blame weather but weather conditions means that person didn't slow down enough for conditions present. Mechanical almost the same thing, brakes or suspension failure the owner of the car didn't check their brakes or suspension components; a tire blew either the owner again didn't check the condition of the tires and or panicked when it blew and loss control of the car. In almost all cases, except maybe a rock slide the driver had some ability to control the situation better than they did either with proper maintenance or better driving skills or not driving when impaired or distracted.

Anywho there is actually a statistical time frame when most fatal accidents occur, between the hours of 6pm and 9pm 15.9% of fatal accidents occur during that time frame; the second most fatal time period is between 9pm to 12 midnight with 13.8% fatality rating; almost 30% of fatal accidents occur between 6pm and midnight...that's quite a high figure for that time slot but it figures because more drunks are out at night which accounted for 54% of those deaths! And yet the drunk killer might get a year at the most in jail if it's their first offense, that is the real crime. Most crashes by the way are not due to mechanical their due to driver error which of course the driver blames other factors but it's all about the driver. Saturday is the worst day of the week.

So the way I see it it's it much closer than 90%, but I buy your premises that it is at least 90%.