With the welsh 20mph speed limits which most cars do not like doing and having to watch the speedo continuously which is taking your eyes off the road a lot as you tend to get paranoid it is unsafe I think, I do know that certain situations it is needed such as outside schools but not necessary as much as on some roads. Anyway This is the reason I have always used a speed camera detector which as least warns me if I do stray over the limit. It has Radar detector and covers most uk cameras in uk and has done me proud.