Quote:
Regina53: I did have a question for you, Glabliser. We noticed that the line for the bus to T3 was interminable. When we got to T1/T2, there were directions to T3. If we'd had to get to T3, might it have been faster to go to T1/T2 and get to T3 from there.
I'm assuming that you arrived at T4?

If you take the bus from T4 to T1/2, you get dropped off at the Flight Connections Centre. If you were really headed for T3, you can clear security at the FCC and then get another bus to T3. The problem with deliberately choosing this route is that you don't know how long the security queue is going to be at the FCC, nor how long the bus queue will be for the FCC -> T3 transfer. But theoretically, yes, it could well be faster if the queue for the T4 -> T3 bus is very long indeed.

There is one further complex option if you have no passport/visa issues. If, when you get the FCC, you discover that the queue for the FCC -> T3 bus is also very long, it is also theoretically possible to cut yourself out of the airside transfer system at that point by walking into T1, taking yourself from the departures stream into the arrivals stream by walking towards some of the gates where there's still mixing of outbound and inbound traffic and doing a U turn to follow the arrivals signs, clearing immigration (hoping that the queue is not too long here) and then walking through the landside tunnels to get to T3. But you'd have to clear security again at T3, where the queue can sometimes be long, so this really is an in extremis option.

Long-haul flying - how to sleep your way around the world.