I have recently installed a GPS device in my car. It knows the time and the location of my car and thus can compute the speed of my car. It has three variable preset limits and if I exceed any of them I am warned. It also indicates when I am approaching a school zone etc.

My problem is unless I am continually scanning the road side verges I can miss a poorly placed or obscured speed sign and thus I am not always able to discern what the speed limit is.

I have a suggestion to overcome this.

There are marker posts on the sides of rural roads. They usually have colored reflectors on them. There are dashed lane lines on city roads.

If colour coded reflectors or painted marks indicating speed limits were placed on occasional marker posts and road lane markings the speed could easily be determined at any time. This would release the need to continually scan for speed signs and allow more driver time to scan for small children and wild life instead.
Geoffrey Nash, Deviot