The speed limit through the roadworks on the M1 is 50 mph.
I invariably - right or wrong - try to stick to the speed limit, or at least not more than three or four mph above it. Granted, that's easier with our car, which has a speed limiter linked to the cruise control, both features which are lacking in the current courtesy car I'm using while our car is in for being fixed. But even so, I make that effort.
When going through the roadworks on the M1, which is dotted with signs saying there are cameras along the road checking average speed, that attempt to stick rigidly to the limit is even more important, IMO.
So driving rapidly up behind me until the front radiator of your vehicle is about all I can see in my rear view window, and then flashing your lights at me impatiently, is not really going to make much difference to my speed.
Jamming your horn on because I don't speed up just for you is going to do nothing other than show you up.
And as for that rather rude hand gesture? Grow up.
I personally have no intention of getting done for speeding. If you do have such an intention, then on your own head be it. It really is no skin off my nose. Just don't expect me to help you.