Travelling along the M3 and M25 recently, it dawned on me that the huge speed limit signs once used at motorway roadworks are no more, replaced by much smaller ones.

I noticed this particularly along the northern section of the M25, where widening is going on.

I'm in favour of speed cameras but I'm wondering if the decrease in the size of the initial speed limit signs is a way of catching more speeders, thus raising revenue. What has happened to those big 50 signs, about 8 ft across, with yellow backgrounds?