If you talk to traffic safety experts, almost all, including those employed by police departments will readily admit that speed limits are too low.
25 is good for residential
65-70 is way too slow for most interstates. The correct speed is referred to as the 85th percentile. Essentially the speed that 85% of drivers are going.
In my last ticket, I was driving through the flats in Montana, high visibility at 180 degrees. The posted speed was 80 mph. I apparently slid above that a bit and got tagged doing 93. Dusk was just starting so I was getting ready to slow down in a few minutes anyhow.
Learn to use your cruise control, even on 25 mph side streets. As a side benefit you will arrive at your destination much more relaxed. Driving on government roads has become a game where the government wins money when you break the rules. A special satisfaction comes when a government hireling gets stuck behind you doing the speed limit. They go bananas.