I would say this is a crooked speed trap. You are dead on about not knowing you are in a construction zone until it is too late. I was coming over a hill where they were working on a bridge, realized it was a construction zone, slowed down to 55 and still got a ticket. The trooper told me the only reason I slowed down was because I saw him and hit the breaks. I told the trooper I didn't realize it was a construction zone until I was going over the hill, and his reply was the exact mile marker where it was posted 7 miles back, with no construction at all between this sign and him. He also said I should know where the construction zones because its been going on for five years. I haven't been down this stretch of interstate in ten years. I wound up paying $281 total and he wrote it up as no workers present( which there weren't, how generous). I guess as the write tickets they can call in another worker and pay his salary for the day.......or two or three.