1995 was the year the national 55 mph speed limit law was changed. If you look at the NHTSA statistics between 1995 and 1996 you'll find that road fatalities dropped about 30% between the two years. You'll rarely see it mentioned, and I don't even know if you can find it in the stats today because they're probably covered up. I submit that the reason for the drop in fatalities is because you no longer had a big disparity in speeds. Before 1996 you had half the drivers doing 55 and half doing 75, once the law changed pretty much everyone was doing 75 and traffic flowed much better, you didn't have everyone constantly passing and vying for position. It's not speed that causes accidents, it's vehicles doing different speeds and the conflicts that brings.
The national 55 mph speed limit killed a lot of people unnecessarily.
Not sure what you are referencing deaths were steadily declining from 88-92 and then they started to rise again.
https://www.iihs.org/topics/fatality-statistics/detail/yearly-snapshot