I have no clue, but some studies by traffic engineers would have shown that 85 mph is, believe it or not, the safest speed to travel on any given stretch of road. I just read 2 years ago that Europe, where overall roads and highways have higher posted speed limits, the number of accidents, injured and deaths per mile traveled is much lower than in the US.
A CBS Texas station just reported that driving 85 mph could soon be a legal reality, at least on Texas highways. The State House has passed a bill that would give the Department of Transportation power to raise the current speed limit. If the bill is voted in Texas Senate, the Lone Star State would have the highest speed limit in the nation. New engineering tests and traffic studies are requested by opponents, with Jerry Johns from the Insurance Institute claiming that higher speed limits would create more accidents, more injuries and more deaths, but without giving any statistics to support his statement. (thank you Keith Thomas),