Originally Posted by
dergon darkhelm
Thanks!
So ...... just use trial and error? Get on a train and if it isn't heading to T4 I have 20 stops to change to the next one?
Or is there signage?
IIRC there's an indication on the front of the train as to which line it is (I believe that it designates which terminals at Heathrow it services). The sign at the station (The one that indicates the next trains to arrive) should also list that. I don't recall if every station has those signs, though.
ETA: If you accidentally get on a Route 1 train you can get off at Hatton Cross and wait for the next Route 2 train. I believe that the conductor makes announcements w/r/t which train you're on and where it will stop at Heathrow.
Remember when boarding the Piccadilly line going to Heathrow
do not get on a train bound for Uxbridge. The Heathrow trains say Heathrow on the front.