text: The speed limit info doesn't show on any of the map layers, but OSM is more than just the visual representation - the data is used by navigation apps/GPS etc. 
  
  But there are a couple of maps which show major roads without speed limits: http://product.itoworld.com/map/125?lon=-5.62025&lat=54.66807&zoom=13 and speed limits themselves: http://product.itoworld.com/map/5?lon=-5.62025&lat=54.66807&zoom=13
  
  The map is fairly simple to edit with the default iD editor. Best thing to do for a quick first edit is to click "edit", then select Groomsport Road, add the 50 mph speed limit, click save and add a short summary of the edit. 