Advisory speed limits that are higher than the regulatory speed limit

[BridgesToIdealism]

I'm not sure if this is just a single erroneous road sign or if there are other examples, but I noticed a rather strange goof this morning. When driving southbound along MA 113 approaching Lowell from Tyngsborough (just south of Greater Lowell Tech High School), there is a standard regulatory speed limit sign that states "Speed Limit 35". All good. However, immediately after said sign, there is a yellow advisory sign warning motorists about a curve ahead, and the advisory speed limit for the curve is... 40 MPH. I'm like, wait, aren't you supposed to slow down, not speed up, on a curve!!??

[GaryV]

I once saw a construction zone speed limit that was higher than the regular limit.

Just this weekend on a state highway I saw an advisory limit on a curve sign that was for 45 mph as I was leaving a town where the speed limit was 35.  Then beyond the curve was a 55 mph sign.  Evidently the speed limit actually went up before the curve, but wasn't signed until after the curve.  Which makes some sense.  "OK, you can go 55 now. Oh wait, go 45."

[vdeane]

I once saw a construction zone speed limit that was higher than the regular limit.

Just this weekend on a state highway I saw an advisory limit on a curve sign that was for 45 mph as I was leaving a town where the speed limit was 35.  Then beyond the curve was a 55 mph sign.  Evidently the speed limit actually went up before the curve, but wasn't signed until after the curve.  Which makes some sense.  "OK, you can go 55 now. Oh wait, go 45."

Some... except advisory speed limits are often quite conservative and not strictly legally binding (ie, you can't get a ticket solely for exceeding that speed, though you could get cited for driving too fast for conditions if you exceed it and then crash as a result), and how would one know where the speed limit change is unless they looked it up somewhere or were familiar with the road?  I always assume it's where the sign is unless I know otherwise and don't speed up until I pass the sign unless I know there's an unsigned increase (someone I know got a ticket for speeding up in advance of the sign).