What is allowable value of weight span and wind span ratio in transmission line?

Its depends on location and type of towers. Supposed the transmission line is erected at hill area and second line is erected in desert area and third one in forest area. Then the allowable value of weight span and wind span ratio in transmission line will different. Also this ratio will depends on types of tower . Like the value is different in 132KV, 220KV , 400KV and 765KV.