In message , at 12:25:29 on
Sat, 16 Nov 2013, Recliner remarked:
Heathrow's layout means that using buses is extremely
inefficient and slow. It would be a major new fleet and an expensive
operation to run. Far simpler just to let the passengers use the trains,
given that the trains are already there.

Are the buses actually slower to get between T4 and T5? You'd need
two Heathrow trains to do it, and they're only 4tpi. The bus route is
fairly direct using the tunnel.

Are landside buses allowed to use the airside tunnel?

And last time I took the airside bus from T4, it was about a 15 minute
walk from the gate. The official time to allow airside for T4-T5 is 105
minutes!! Even more than the 90 minutes T4-T123.
--
Roland Perry