Letter: I Still Think A Tunnel For A281 Traffic Is The Best Option

Published on: 20 Aug, 2016
Updated on: 20 Aug, 2016

From Bibhas Neogi

I agree with John Rigg when he says in his Dragon Interview: “We think that a new east-west crossing is an essential piece of infrastructure if Guildford is to survive. We believe that bridges, while expensive, are cheaper.”

But I do not wholly agree with him when he says; “Tunnels typically will use more land at each end and generally are not very attractive in an urban setting.”

A short tunnel like structure (not a real tunnel) under Millbrook and part of Onslow Street would require some realignment of surface lanes that are to be maintained for emergency vehicles, buses, taxis and cycles.

Tunnel portals of a two-lane tunnel at the locations I suggested would not be visible from most of the town centre area and in my view should be a cause for concern.

At the southern end, some incursions into the car park area and the land in front of the old tunnel portal under Quarry Street would enable the surface lanes to skirt around the tunnel portal. At the northern end the road is wide enough to accommodate a surface lane in each direction around the tunnel portal.

The “tunnel” could be built partly as a cut and cover and partly as a ‘top-down’ method. Traffic management would require to be worked out to keep disruptions and delays to an acceptable level. The link over the railway would need to be two-lane wide and the flyover could be terminated at Mary Road. I have described this option on my website that requires no changes to Park Street, Farnham Road Bridge, Guildford Park Road and much less demolitions of buildings along the route.

I think this alternative has many advantages over the GVG scheme and should be explored by the councils. There are other improvements that I suggested for the area around the station and Walnut Tree Close that compliments this arrangement in order to provide a much better flow of traffic, pedestrian and cycle routes together with relocated bus station on Mary Road car park and modified bus routes to connect the town centre and the railway station by all routes split to suit.

My website could be found by searching for ‘revamp guildford gyratory’.

Responses to Letter: I Still Think A Tunnel For A281 Traffic Is The Best Option

Jim Allen Reply

August 20, 2016 at 4:06 pm

Perhaps someone should go to Madeira and look at how they use tunnels and report back with a worm’s eye view of a surface problem which can be solved – if the will is there!

Or Gibraltar where there are reported to be more roads in tunnels than on the surface. Ed
- Bibhas Neogi Reply
  
  September 28, 2016 at 6:30 pm
  
  In reply to Jim Allen,
  
  Thank you for your comment. I did look at a website that showed various tunnels in Madeira and I was impressed at the way they had tackled the problems of hilly terrain.
  
  The ‘tunnel’ that I have suggested to put the A281 under Guildford town centre stretch is not a true tunnel at all and compared to Madeira tunnels, to construct it would be a piece of cake!
  
  It would be a lot easier to build than a tunnel using boring machines etc. because in reality it would be like constructing a bridge with approximately 12m span that is very very wide – in fact some 800 metres wide.
  
  I estimate the cost would be about £40m on the basis of £4,000 per sq m of deck area. Maybe this would help the councils to rethink about the ‘tunnel’ idea.
Bibhas Neogi Reply

September 27, 2016 at 11:15 am

There is no doubt that tunnels are expensive road infrastructure but the cost depends on at what depth in the ground they are located and how they are constructed. A ‘tunnel like’ structure on the other hand could be build just under the road surface without using any actual tunneling machines.

Basically such a ‘tunnel’ is like a string of underbridges whose spans are the widths of the ‘tunnel’ along its length and are joined up side by side that make up the total length of the ‘tunnel’. The cost is therefore comparable to building bridges rather than a more expensive tunnel.

I have illustrated this method with simple sketches for such a ‘tunnel’ under Millbrook and Onslow Street to take the A281 under the town centre and thus make the area pedestrian friendly. These are described in the website below,-

http://s1130.photobucket.com/user/Gyratory1/library/?sort=3&page=1

I have suggested improvements and modifications of road network around the railway station such as a bridge over the tracks and continuing the route on a Flyover towards Mary Road plus a new river bridge from Walnut Tree Close to Woodbridge Road. All these are longer term improvements.

I have also suggested a relocated bus station on Mary Road car park site. The bus routes could be split to serve the railway station and the town centre with a satellite hub built-in with the Friary Extension or located near Leapale Road. This would be a vast improvement compared to the current location of the bus station. The routes would use three different roads that lead to the bus station and so reduce congestion even further.

For the shorter term, inexpensive improvements to the gyratory are also described in other sketches together with wider footways and cycle lanes into the town centre that would become permanent features.

For the main website please search for ‘revamp guildford gyratory’.

I hope the councils would reconsider their plans for the town centre and improvements to the traffic through it in the light of my suggestions for the benefit of all.
Bibhas Neogi Reply

June 8, 2018 at 3:31 pm

The aspiration for a traffic free town centre seems to have died down. The councils, as far as I am aware, have not put forward any idea of how this could be achieved.

Recently I have come across a promotional video of extension of Kolkata (old name Calcutta) Metro. This video shows how top down construction could be used to put trains underground as well as conventional tunnelling methods.

In Guildford the north south corridor of the A281 could be put underground using a similar top-down construction method that I have illustrated on my website. Whereas this video shows the method that uses diaphragm walls and a road deck spanning between them, an alternative of contiguous piles could equally be used instead of diaphragms walls. The video could be found in https://www.youtube.com/watch?v=SuLIZeoCyGU

The reason I have chosen to cite this video is this that a relatively poorer city of Kolkata is able to expand its metro network quite substantially but a prosperous town like Guildford seems unable to muster anything that would really improve the road network.

Are councils not interested in improving the traffic flow since they have bought into the idea of ‘modal shift’? Or do they lack the vision and the courage to tackle a difficult problem?