My commute takes me along the A412 from Denham to Slough. There is a short length of dual carriageway between the A40 and Iver Heath, single carriageway through IH and then another stretch of dual carriageway (about 2 miles before you get to all the traffic lights) into Slough. Both sections of dual carriageway are NSL. At least they are today. This morning, along both sections, there are new metal poles set along the verge, most of them having a round, metal plate atop, covered in black plastic. I reckon this means that it will be a 50mph limit in the very near future. I also spotted smaller poles at various intervals, most likely for repeater signs. Ah well, at least it will make it easier to do double the speed limit for while. I wonder how long before the speed cameras are installed.