This morning, I joined a westbound Circle Line train at King's Cross St.
Pancras. As we arrived at Edgware Road (platform 4) a westbound train was
just leaving platform 3, so our driver announced that passengers for the
westbound Circle Line should cross the footbridge to platform 2. I knew
that he meant the other kind of westbound Circle Line train, i.e. one that
would reappear as my kind in about an hour, so I chose to ignore the
instruction. But what should he have said to have made it clearer?