wrote to uk.transport.london on Sat, 5 Feb 2005:

Why does it take so long for bus drivers to swap over and why is it
done half way through a route?

It doesn't always take a long time if the replacement driver is waiting
- just the time for the getting-off driver to log out, and the
getting-on driver to log in. But you can wait ages if, for some reason,
he or she isn't waiting at the bus stop!

I agree, I wish they would warn of a crew change mid-run; I find the 159
is particularly prone to changing crews at Brixton garage. The only
time other buses stop there is if the driver is "taken short".
--
"Mrs Redboots"
http://www.amsmyth.demon.co.uk/
Website updated 23 January 2005 with new photos