Re: Sigh.
It's perfectly legal to do 25 mph in a 30, but if conditions are suitable for 30 mph then it's not very clever.to do 25. Because the road isn't just for one person and the compression of traffic behind a slow driver causes other knock on problems. And do it on a driving test you will get at least a minor strike against you.
Thais piece of tape on a sign thing, interesting because my car shows the speed limit on the satnav, presumably from its own database. And also reads the posted speed limit from the road signs and they don't always agree. Especially in temporary reduced limit signs for roadworks. My car alerts me and then takes the lower option.