The parallel taxyway at LGW doubles as a stand-by runway
Exactly so, I have used it 2 or 3 times this year alone, a bit shorter than the main and no ILS but not a problem for aircraft in normal conditions, if conditions are going to be a problem they normaly leave the work and keep the main RW operational.
( I believe the A1 next to one of the Yorkshire RAF bases had skidmarks
across the road and this was pilots touching down on the road for fun, then hoppng over the fence to land on the runway not sure if there is any truth in this or just apocryphal)
