Earlier quoted context omitted.
20% means you drive at 80 in a 65. That is in no way acceptable.
There is a lightly trafficked, mostly straight, 2 lane highway between where I live and the closest city large enough to need 5 digits on its population signs. The speed limit is 65. I drive 75 on it. Most people drive 85. In fair weather, with the right vehicle, 95 would be safe for most of it. A few years ago, the limit was 55, and at that time, a sheriffs deputy told me they don’t bother anybody going under 70. I…
IMO roads with 80 MPH speed limits are much safer. Even the crazy folks don’t go much over, so you don’t get a huge delta in speed, which is a lot more dangerous than any absolute number.