Whilst I share some of the environmental concerns, the EU opinion seems utterly blinkered. This is not just about economic reasons and its justification seems flawed.
The reliance on the current road has proven to be a threat to life when road closures due to problems with the road surface during winter rains prevented (for a period) ambulances on serious emergency work from taking the only real route. This is not a simple fix of upgrading the current main route, the problems are widespread. It’s not possible in many many areas to widen the existing road, for example. Disruption to local power lines, water supply, telecoms etc the current road provides will be massive.
The shear economic impact of upgrading this road, the massive delays to existing traffic for years and years and resultant increased pollution from traffic backing up, will have a significant impact both on those forced to use the main access route and local traffic that uses this road for even relatively short journeys.
A straighter, more direct route also has an impact on road safety, accidents, pollution close to village population centres, schools, etc. Wildlife is likely to repopulate the area’s on the existing road if the majority of traffic is taking a faster more direct route.
BT had a different point of view though
Personally I don’t think there is an awful lot wrong with the road considering the size of town /area at the north end.
Also there is an alternative route which is in distance not too different and also not that bad although a bit twisty.
Don’t know how it could be justified building a new highway.