Full-width hard shoulders are provided on most new, upgraded (from the 1980s onwards), and major "national roads" in the Republic of Ireland, especially on wide two-lane and dual-carriageway roads (the shoulders on most 2+1 roads are narrow however). They are defined within the official document the "Rules of the Road" as a part of the road that should normally only be used by cyclists and pedestrians. Their provision of on interurban routes in the 1970s reportedly resulted in a 50% decrease in accidents involving pedal cyclists.