On Tue, 6 Jun 2006 17:14 +0100 (BST), Colin Rosenstiel wrote:

do the Jubilee and Metropolitan Lines share tracks between Baker
Street and Finchley Road?

At Baker Street the Jubilee (was once part
of the Bakerloo) is in a tube tunnel, and I don't think the lines
merge until Finchley Rd. Even then, they stay as two pairs of track,
each dedicated to one of the lines.

But there are crossovers which allow trains some interchange between the
tracks of the two lines.

Weren't these removed sometime in the past few years?