On Wed, 29 Sep 2010 00:26:24 +0100, Roy Badami
wrote:

In some
places, roads merge then separate but keep their numbering before and
after.

That happens here, too.

The difference is what happens during. In the UK, the common section
has the number of the most major road (only), leading the minor road(s)
to be discontinuous. In the US (and I think in many parts of Europe?)
the common section bears multiple designations.

Yes, but the point being made is that combined roads in the US also
keep their N/S or E/W designations regardless of true compass bearing.

We don't append the direction to our road numbers, just provide
generic 'The NORTH' or 'The SOUTH', etc. directions at certain
junctions.