UK Mapping Priorities
UK Mapping priorites was a historic wiki page that listed poorly mapped towns with a population greater than 50,000. It attempted to score the completeness of the map of each towns by dividing the population by the OpenStreetMap filesize for the town (with higher scores indicating less 'completeness').
As the remaining missing roads were added to OpenStreetMap this page became increasing out of date. It has therefore been removed for the time being. If you are interested in bringing this back, please discuss on the "talk-gb" mailing list.