New speed cameras on the A27

I went to Eastbourne today, and noticed there are two speed cameras between Falmer (Sussex/Brighton University) and Lewes where I work, one just after the University bridge and another a mile or so further on. They're both currently pointing East, ie Brighton -> Lewes. It was hard not to notice, as the cars in front slowed down to 30 mph (which is not in fact the national speed limit, no matter how much people who drive on Sundays wish it was)

Not really a problem for me in my old car. They look a bit temporary, I wonder if they're the harbinger of catastrophic roadworks?

Edit: the cameras have been covered up ever since, and the sign saying roadworks are scheduled has been taken down.