WHO put the new speed limits in Rishton?

Coming from the roundabout towards Rishton, the limit is 50mph, and when you reached the Rishton Reservoir, it went to 40mph.

But since coming from holiday, I find that the speed limit has been changed to 30mph when you reach the reservoir.

How can you drop your speed from 50mph to 30mph in such a short time?

I can see a lot of motorists being fined for speeding as I find I cannot drop from 50 to 30 in time.

A JACKSON, Fielding Street, Rishton.