On Mon, 4 Sep 2006 13:25:16 +0100, Clive D. W. Feather wrote:

Could it be to let them get experience with the effects of pathing
the ELL on to the NLL, before it opens?
That's what I thought, but it doesn't seem to work - it must either run
to Dalston Kingsland or Dalston Junction; if it's the former, then
wouldn't they need to build expensive and temporary turnback
facilities? If it's the latter, then there seems to be little point
running a precursor when the proper ELL could be run through.

Not if they build the junction, with temporary buffer stops on the ELL
route, early, well before finishing the rest of the ELL stuff (in
particular, the link from Whitechapel to the viaduct).

The link from Whitechapel to the viaduct is part of ELLX Phase 1. The
connection from Dalston Junction to Canonbury, and through running
onto the NLL, is part of Phase 2, so it won't need to happen till much
later.