Off topic, but one of the more maddening things I see here in the US is signs which say "End thus-and-such speed limit." I don't want to know what the speed limit was. I want to know what it is!
In much of Europe, including the UK, they have the concept of standardised "national" speed limits, which vary depending on the road type and which you are expected to know. When a road returns to the national speed limit, the sign is a white circle with a slash through it, indicating that there are no more local speed limits and the national speed limit is in effect.
I find this easier to remember than the constantly changing limits in the USA. In my two weeks here, I've seen every multiple of 5 between 5 and 70mph.
I never quite saw the point though -- my response is the same either way: adhere to the limit that applies going forward. (I suppose maybe it's useful feedback of inattention and the need for rest?)