A3290 50mph Limit .....Why?

[silverfoxcc]

Going north on the A3290 ust past the Winnersh Turn off there are two 50 mph signs. Now the only thing i can see are a couple of cones just on the 'hard shoulder' just past the nearside sign. There is no End Road works to get us back up to 70 BUT on the old upslip ramp there is an NSL sign visibl from the main carriageway. Could this be used as a sign to get up to 70?
Or can anyonw explain why they are there?