When planning a new runway, it used to be a reuqirement to furnish decades of 'prevailing wind' data to determine runway direction, when crosswind component was more important to commercial aircraft. however, my experiences of nearly 2 decades at a large aerodrome in the South-East with a currently 08/26 orientation was that this 'prevailing wind' idea is no longer relevant. A North-South orientation would have been much better at LGW, because whilst all the current a/c using it would have been easily able to cope with 260/10-15 winds, almost invariably the Winter lows brought surface winds of 180/30G45, a real challenge on 26L, especially coming out of the lee of 'Laker's Revenge' or Hangar 6 as it used to be called.
Generally the operational split between 26 & 08 ops at LGW was/is around 70/30 respectively. The results for LHR are slightly skewed as they operate a Westerly preference i.e. will accept up to a 5kt tailwind on 27L/R - easily accommodated by the length of the runways. The recent closure of 23 at LHR was I suppose a demonstration of the cross-wind tolerance of many modern large aircraft(05 closed many moons ago). STN's runway 05/23 remains the best dirty-weather runway in the South-East.
Of course non of the above helps us types flying a/c with a demonstrated crosswind performance of only 17kt!
TheOddOne