I thought I knew the national speed limit but not sure if I've been caught out or not, driving down from Cumbria today there was an odd looking speed camera on the A 590 at a place called Townend, it's the new road that has Clearway circular signs and a mile or so further on it is a dual carriageway, I was doing 60mph as I passed the speed camera as I was certain the clearway signs allowed that, i had passed the national speed limit signs (white with black diagonal) earlier along the previous dual carriageway. Does anyone know what the speed limit would be at that point?