In most cars not at 30mph but you're right you're revs will race if you go over. Try it, you may be surprised
Sometimes it's not only about money........... if doing that makes you keep your speed down and so prevents you from killing or maiming someone then, in some people's minds, it is worth it
30mph in 4th gear 1700rpm
30mph in 3rd gear 2100rpm
Which ever way you look at it the engine is turning more in 3rd gear at 30mph so it will cost more.
I understand what you are saying about slowing down. I am all for road safety, which is why I think there should be speed cameras outside every school to start off with. But there is such a thing as inappropriate speed, and that is what is the killer.
40mph in the Bidston Bypass is an insane speed limit for a road that was previously 70mph, and absolutely nothing has changed on that stretch of road.
There are areas of the Wirral where the speed limit is set unreasonably low, and there are areas of the Wirral where the speed limit is set dangerously high. Yet the powers that be dont exercise common sense and do anything about it.
You find me 1 person that would object to 20mph and a speed camera in front of every school in the borough. Yet they wont do that. What they will do is nearly halve the speed limit on a piece of road that has been perfectly safe up to that point with a 70 limit.
I dont think anyone would condone inappropriate speed, because it is simply dangerous, a lot more dangerous than 35mph in a 30mph road, when that road is the Wallasey Dock Road with little to no pedestrian activity.