Originally Posted by
CATIII-NDB
"In fact LHR used to have 4 -6 runways until they closed the cross runways to expand the Terminals........................"
With modern computing technology was this in part a mistake ? - Not all Six runways; but perhaps keeping two.
Hardly.
One of the cross runways was in use until about 15 years ago, but its existence made no difference whatsoever to runway capacity.