Mostly military aerodromes. Unfortunately. I think they are great references. But in this day and age of runway analyses and balanced fields i.e. go/no go takeoff speeds, the bean counters and the regulatory agencies deem these signs as completely unnecessary. In the old days, they could be used to monitor takeoff acceleration. Nowadays we have much better engine instrumentation and higher thrust engines.
So in the end, the signs would be nice to have but not all that useful given the reality of today's equipment and takeoff analysis data. Additionally, in most places in North America where winter snow is a factor, it would be an extra cost to keep the signs clear of snow not to mention lit all year round.