The airport' s runways are too close to each other to allow simultaneous use of adjacent runways when visibility is poor
the airport allows only 30 planes an hour to land in poor weather; in good weather 60 planes an hour are allowed to land. Because airline schedules assume good weather, bad weather creates serious delays.
In poor weather, only half as many planes are allowed to land each hour on any one runway at the airport as are allowed to land on it in good weather.