and when people go significantly under.
How would you ever monitor WHY someone is significantly under? I've even followed an ambulance with blue lights going at snail pace - god knows who was in it, but that didn't look good.
The queue of traffic behind you means nothing either - don't tell me you've never been in areas where cars just speed. Zone with road work suddenly going to 30mph come to mind, despite constantly repeated 30 signs , cars just try to zoom past and make it clear you should drive a lot faster. Why isn't there more cameras in these zones, I'll never know, they' ll make a fortune.
I can think of many more where traffic catches up with you far too fast even when you are going slightly over the limit yourself, and builds up behind. Being at the front of a huge queue of traffic doesn't mean you are too slow - if you NEVER are, it means you are going way too fast.
That's your problem, but I won't pull over to let you go through, I won't accelerate because you try to intimidate me, if you are not happy with the limit, contact whoever is in charge of them, don't try to push people to crash.
If you plan your trip at the second and cannot tolerate anyone in front of you , you are a bad driver. There are lorries, slower vehicles, learners, road incidents, thousands of reason why the traffic won't go as fast as you think you should. SO WHAT?
Most drivers completely overestimate their own driving skills.