The tunnel would be nice ,but the country can’t afford it at the moment.
It is purely a vindictive vanity project.
Widening the road is cheap, this would allow the site to be investigated then the tunnel built when we can afford it.
As was settled with the prevous government before the current redevelopment began.
Thanks moose07. There was a discussion about the relative merits of road-widening as well — the complaint often is, it just spread out the traffic and made formerly quiet towns noisy. But that’s what they’re intended to do. :’) I wholeheartedly agree about the cost of tunnels. Much cheaper to put a sinewave barrier (perhaps in polymer) to counteract the racket.
http://www.bbc.co.uk/programmes/p01gydzp