It could be the road that has been longest in planning, and even though it now has the go-ahead, it could still be nine years before a single private vehicle moves along its whole length.
The Transmission Gully project, for which consents have been recently granted by a Board of Inquiry, is part of a Road of National Significance on the northern corridor from Wellington Airport to Levin. It is expected to cost about a billion dollars for 27 kilo- metres of road through an inland route generally following the path of transmission lines from Linden (near Tawa) to the current State Highway 1 at MacKays Crossing near Paekakariki.
It duplicates the current coastal high- way but is located further inland.
Funding, technical issues and local arguments have confounded decisions about the road ever since it was first proposed.
Even the date the road was first mooted is shrouded in controversy. Popularly it is believed the United States Marines offered to build the road to help move troops and equipment from their Paekakariki base to the port of Wellington during (or after) the Second World War. Even though this is regularly referred to, authentication is hard to prove.
Former Commissioner of Works, Bob Norman, who was a cadet in the Department of Public Works in the early part of the Second World War, says he never “encountered anyone who has ever said that”. Historian Dr Michael Bassett, who has written a biography of wartime Prime Minister Peter Fraser and a history of the Department of Internal Affairs, says he found no reference to such an offer in any of the papers.
The consultants’ report, “Assessment of Environmental Effects”, which was prepared for the planning hearing, says “there is a persistent ‘urban myth’ (which the NZ Transport Agency – NZTA – is unable to confirm or debunk), that the United States Army offered to build an inland route during or soon after World War 2. The NZTA does not have records of any of these early considerations of an inland route.
In any event, Mr Norman adds, (if true), “the Marines would probably have built a military track. They wouldn’t have built the kind of high- way we are now talking about. There would have been limited earthworks and Bailey bridges, just enough to move their military equipment around.”
Back in 1919, the Evening Post reports on a local Member of Parliament and surveyor, a Mr W H Field, introducing a delegation from the Hutt County Council to the then Minister of Public Works, Sir William Fraser. The delegation wanted improvements to the Paekakariki Hill Road, then the main route out of Wellington. It said the road was dangerous compared with a proposed new coastal route via Plimmerton and Paremata.
Mr Field, however, mooted an entirely new road. The report continues that “the question of a better route should receive attention at the hands of government. So (Mr Field) urges a new road (other than Paekakariki) by way of Pukerua, or a better one if available, to avoid the hill and its dangers”.
The first Labour Government built Centennial Highway from Wellington up the Ngaraunga Gorge to Tawa.
This four-lane highway was opened in 1940 – the centenary of the Treaty of Waitangi. Now there will be a second route north from Wellington. According to the NZTA, the current timetable for the Transmission Gully project “sees construction beginning in 2015 and completed by 2021”.
Assuming the road is completed on time, it will be just over a century since the idea of a second northern road out of Wellington was first mooted. So why has it taken so long, and why a second road at all? The answer is a combination of feuding local politics, arguments among various professionals about technical matters, and a shortage of money.
Transit New Zealand (the successor to the National Roads Board and the NZTA’s predecessor), was for a 14-year period the nation’s state high- way system’s builder. Former Chief Executive Dr Robin Dunlop (1989–2004) puts most of the blame on the benefit-cost ratio approach.
“At Transit we started working with benefit-cost ratios of 10 (to one), and finally managed to get them down to five, but with the difficult bits [of roading] the BCs [benefit costs] were around one or two, so they weren’t on the radar screen. Transmission Gully was like that.”
(The NZTA’s ratio for Transmission Gully is currently somewhere between 0.8 and 1.0.)
“The root cause of the indecision was funding. If the money had been there the decision would have been made earlier,” Dr Dunlop says. “A Pukerua Bay route was possible, but no one really wanted four lanes spilling out into the sea. In engineering terms it was feasible, but it was unattractive environmentally.
“Transmission Gully was relatively straightforward in engineering terms, although there were debates about the use of tunnels and bridges. These weren’t anything major. I never saw the engineering issues as big ones; to me it was always a money issue.
“What was important was the decision to look at strategic routes and work out how to deal with them.
The BC system left all the tricky bits behind: Waterview, Huntly Bypass, Transmission Gully.
“Transit NZ advanced a corridor approach where you look at a whole stretch of highway, – Wellington to Levin for example – and funded the whole stretch accordingly,” Dr Dunlop says. This eventually led to the Roads of National Significance policy, for which the current government has made considerable extra funding available.
The most recent round of local controversy began in 1986 when the Ministry of Works released its five- year study into options for relieving congestion on the northern route out of Wellington. It recommended dropping the inland route and widening the coastal route. That touched off 20 years of local argument as politicians and communities sought to overturn that conclusion on technical and financial grounds. However, others think there were, and still are, difficult technical issues associated with the Transmission Gully route.
Mr Norman is one who is concerned. He wrote to the then Minister of Transport, Annette King, in 2007 setting out his objections. “There will be large, long limiting gradients, much longer than Ngauranga Gorge and equally steep, with significant fallout in fuel costs and exhaust discharges.
“The new alignment will be through highly faulted, geologically unstable country with potential for frequent rockfalls. This is the sort of problem encountered in Cromwell Gorge and the only safe solution was to provide, at great cost, additional shoulder width to accommodate the falling rocks.”
In its final decision released in June 2012 the Board of Inquiry said, “Transmission Gully will (provide) a new four-lane route which will avoid congestion, reduce travel times and achieve consistency in travel times.
The new route will be safer than the coastal route.”
At present, the NZTA’s Wellington State Highways Manager, Rod James, says staff are “working on determining the best delivery model for the funding and construction of the Transmission Gully route – work which is to be completed in the next three months”. He says the NZTA is confident construction will be finished within a six-year timeframe based on experience with other highway projects in New Zealand and overseas.