Bob Cotgrove, in his excellent summary of road transport issues facing Hobart (The Mercury 11 Jul 2015,) challenges our political leaders to take “a realistic look at current and future urban travel behaviour and plan accordingly”.

To Bob, that means investigating as a matter of urgency a western arterial bypass around Hobart CBD, to connect the southern outlet with the Brooker and Tasman Highways following the route of the Northside Freeway as proposed in the 1964 Hobart Area Transportation Study.

Fig 1 (see note 1)

It was unfortunate but hardly surprising that political leaders at the time did not approve and fund the bypass, but they could hardly afford both the bypass and the hydro electric schemes then under construction. However, what they might have been able to do was to place road reservations preventing new or further development over the proposed route. Sadly, they didn’t and the absence of road reservations has allowed the development of many more homes, businesses and offices over a period of five decades.

Today, these could not be compulsory acquired and demolished without incurring massive costs, before the first bucket of concrete was poured into a new road. Even if it were affordable, today’s laws protecting heritage properties would most likely render the project politically impossible. Imagine the reaction to the Battery Point walkway and multiply it by 100! Clearly then, if a Western Bypass is Hobart’s only option and if we can’t go over it, then we have only one option … we have to go under it.

Hobart needs a tunnel!

Indeed, a tunnel was also proposed by Bob Cotgrove twelve years ago (the Mercury 17 Mar 2003) who recommended that it be put through a full social cost benefit analysis.

“Certainly one can look at a number of benefits that would come from getting traffic underground, and also of course there are the substantial costs, but it’s something that needs to be looked at,” he said.

During last year’s election campaign the RACT hosted a forum on traffic solutions with a panel of political candidates and traffic commentators. No new solutions were identified and panellists mostly agreed tunnels were too costly and wouldn’t solve the problem.(the Mercury March 04, 2014)

At first glance the Western Bypass Tunnel may indeed be unaffordable and if the full cost were to be recovered through tolls, it may also be politically infeasible. But let’s take a closer look. The 1964 proposed route is approximately 4 kilometres long, but what if it could be shortened or even halved? Do we really need a tunnel to cover the entire distance of the bypass?

What if, instead of a bypass tunnel looping around Hobart and connecting to the Brooker Highway at Burnett Street, it took the direct route under Davey Street, starting at the entrance to the Southern Outlet and exiting near the railway roundabout / cenotaph at the start of the Tasman Highway? The start of the Tasman Highway between the railway roundabout and the bridge may need to be upgraded and widened to ensure traffic disperses quickly and the feasibility of a expanded car parking on the domain explored.

“We could name the Davey Street tunnel “Ringini”, after the indigenous word for burrow”

Such a project would have many advantages. Firstly, it would fix what is without doubt the worst of the worst traffic problem in Hobart, the Macquarie Street/Davey Street “chainsaw” that bisects Hobart and can only get worse as Hobart expands. Furthermore, it would facilitate traffic flow from the southern suburbs of Kingston to the northern suburbs and improve the flow from the southern suburbs to the Eastern Shore. Last but not least, unlike the 1964 ring road plan, a tunnel would be visually unobtrusive and not affect existing buildings or heritage assets.

But could even such a shorter tunnel, when coupled with improvements to the Tasman Highway, now be affordable? It is clearly beyond my expertise to estimate the cost of the Davey Street tunnel, especially if it were to be a bored tunnel and not a cheaper “cut and fill” tunnel (just imagine closing Davey Street for a year or two while one was being built!).

The cost would depend on many variables, not the least being the type of rock and geology to be drilled through but perhaps an indication can be derived from recent tunnel projects. The $2.65 billion NorthConnex tunnel in Sydney, to be built by the NSW and Federal Governments and the private company Transurban, will be 9 km long, or roughly $300 million per kilometre of 6 lane tunnel. $300 million / km also seems to be a median cost, when looking at tunnel costs around the world.

* data prepared by Alon Levy

The proposed 2 km, 4 lane Davey Street tunnel could then be estimated to cost about half a billion dollars, including $100m to upgrade the highways at the access/entry points. Half a billion dollars, is that too much? What will Tasmanians in 40 years time think of the half a billion dollars spent today? Perhaps we should look at what Tasmanians were spending on tunnels about 40 years ago. On June 11, 1977 the HEC completed the 1km Gordon River tail-race tunnel at a cost of 10 million dollars! It was a project that took 2 and half years to complete, on time and within budget, through the hardest and most difficult of rock, in an isolated location, with a workforce of 150 and led by civil engineers using slide rules (including my late father, John Willink).

“Lets get the Hydro to build it!

I guess the point that I am trying to reinforce is that large sums of money are realistic when considering infrastructure projects with many decades of useful life and in the current environment with record low interest rates. They are also realistic in the prevailing political climate with a Federal Government keen to commit funds to large infrastructure projects.

Who can forget that only 5 years ago the Federal Government was prepared to spend a billion dollars on a new Royal Hobart Hospital, twice what might be needed for a tunnel. Current polls indicate that next year’s Federal election may again be close with the prospect of another hung parliament and with the seat of Denison again in a position to negotiate additional funding. Clearly, we need fully costed and shovel ready projects, if we are to take advantage of opportunity funding and the Ringini tunnel might just be the sort of project the Federal Government are looking for. When the funds are approved, just one more thing … let’s get the Hydro to build it.

*Hans Willink is a former Army Officer, IT Director and political candidate. In 2014 he campaigned in support of an Eastern link road extending the Flagstaff Gully Road to connect the Tasman with the East Derwent Highways, bypassing Lindisfarne and reducing congestion on the Tasman Bridge.

• Ben Cannon in Comments: Not realistic solutions? Look at a graph of public transport usage by state. You’ll notice that every other state has gone up since the 70’s, while Tasmania has gone down. Why? Because of that same mantra about how everyone should just get a car that lead to rails being ripped up. Public transport in Tasmania has received little more than lip service via a few buses which are often crowded beyond even standing capacity at peak hours. If most people have a choice they will pick an hour by car over 2 hours by bus. If most people have a choice they will pick 1/2 an hour by rail over 1 hour by car. How many people will pick a modest fare on reliable public transport over expensive inner city parking fees? That’s why rail elsewhere is struggling to fit enough trains on the tracks without building new lines …

• Ben, Melbourne, in Comments: Tony Abbott rejecting sustainable solutions such as rail is no surprise. The self proclaimed infrastructure pm has done little for such other than fund a few roads. Melbourne has a population of 4 million. It has 25 tram lines at an average distance of 10km and 16 train lines at an average of over 20km each and 9 arterial bus routes at an average of 40km each. There are also a lot of feeder bus services. Just based on the two forms of rail and arterial bus, this equates to roughly 1km of rail or arterial bus for every 4000 people Most train and tram routes are so packed at peak hour that even finding standing space can be difficult. Using this formula for Hobart we arrive at 50km of rail for 200,000 people. A Bridgewater to Kingston line would total about 30, Bridgewater to Lauderdale would be similar. Add on a little for rail across Tasman bridge. You’re left with a similar ratio to Melbourne. Current bus services along these routes suffer similar overcrowding.