[Talk-GB] Road route relations in the UK

[SomeoneElse]

When looking at a bit of the A1:
http://www.openstreetmap.org/browse/way/34158443
I happened to notice that it seems to belong to 6 route relations.

There's a bus route, an E road (both of which make sense) and 4 A1s 
(which don't), one of which (103597) seems to have a lot more versions 
than the others.

I have two questions:

1) Why the need for 4 A1 route relations?

2) Why the need for even one?  After all, the "ref" tag on all the 
component parts of the A1 should identify them without the need for a 
relation.

Yours etc.,
Confused of Derbyshire