Why have tunnels at all??
They need to be shut for maintenance.
https://m.dailyexaminer.com.au/news/highway-tunnel-will-close-this-week/3573423/
Very good question Jon. Some of the excuses are drawing very long bows. The main excuse is tunnels are quieter then cuttings.
- Some how in the darkness of a tunnel, black magic happens and noise just disappears, where as with cuttings the noise will reverberate around the natural amphitheatre around West Coffs and the noise will be continually deafening. Even though the requested tunnels are sort of at the extremes of the Bypass as it passes around the back of Coffs, I just can not see any advantage of tunnels suppressing any noise when the open Bypass passes closer to the residential areas.
- A technical excuse is the angle of the roadway is increased by having cuttings, the tunnels are dug deeper lowering the elevation of the bypass by a whole 10 meters over in West Coffs.
- The natural backdrop of Coffs Harbour will forever be scarred by cuttings so to keep the natural beauty of private property slowly being over taken by suburbia there must be tunnels. The Bypass does not go above the existing scars on the private property that has been cleared and being developed.
- the best excuse I saw was the massive cutting on Gatelys Road, the northern cutting, due to it's size, 60-70 meters deep 380m long and not sure of width, but the cutting will change the landscape to the extent it will also change the climate of Coffs Harbour.
I agree, why the need for tunnels. Collectively the tunnles at best will make up just over 1km of a 14km bypass. I just can not see sufficient noise suppression of a tunnel, compared to the noise from the open road, to the majority of the residential areas of West Coffs to justify the additional cost in the additional construction and infrastructure of tunnels. Further when you look at the ongoing, ever increasing cost of the scheduled , ongoing maintenance of tunnels, two nights per tunnel per every three months. The ongoing cost , again I just can not see the justification for it. That expense could be better used else where, either other road construction or health, education, law etc. What school or hospital will knock back a lazy $1m a year.