> That's one thing I found weird driving in the US. Everyone consistently drove about 5 mph above the speed limit
This is the same in Europe as well. At least from my experience(-s) of driving in Lithuania, Netherlands, Poland and Germany.
> If people, including law enforcement are comfortable with doing 70mph on 65mph roads, why not make the speed limit 70mph
The speed limit is set based on what is considered safe upon collision in a particular area. Furthermore, if you increase the speed limit from 65 mph to 70 mph, you'll likely see drivers going at 75 mph.
This is the same in Europe as well. At least from my experience(-s) of driving in Lithuania, Netherlands, Poland and Germany.
> If people, including law enforcement are comfortable with doing 70mph on 65mph roads, why not make the speed limit 70mph
The speed limit is set based on what is considered safe upon collision in a particular area. Furthermore, if you increase the speed limit from 65 mph to 70 mph, you'll likely see drivers going at 75 mph.