Is it technically legal to exceed the speed limit when passing? Don’t get me wrong, I’m not saying no one ever speeds. I’m just wondering what the reasoning would be in this case. Seems to reify speeding, if anything.
There's also what I've observed (not sure if there's an official name for it), that if you pass someone slowly, they will "lock tractor beams" onto you and start to match your speed. So you want to have a noticeable speed difference between your vehicles to prevent this.
But as long as you're only going a few miles over the speed limit for a few moments, nobody's going to write you a ticket for it.
One of many situations where the law in theory and practical application differ, since officers are given discretion (read: ability to apply common sense) in their duties.
It's not a perfect system, but it's what we've got.