In article , Roland Perry
writes
I have never in my life seen construction companies do this
even when the new road is well away from the old route
It costs millions extra to do it that way

Come and look at the A14 rebuild between Girton and Swavesey. It's being
done in a similar way.

And there's only disruption to the through traffic for two isolated
overnight periods (while they switch some virtual points)?

You have got-to-be-joking.

Let's see when it happens.

At the moment, the next disruption is a closure this weekend to demolish
what's left of the old Bar Hill flyover. Closures for this sort of
thing, or installing gantries, seem to be more disruptive than switching
the alignment.

--
Clive D.W. Feather