WELLINGTON’S £20m FOOTHILLS MOTORWAY

Press, Volume CVI, Issue 31327, 25 March 1967, Page 5

WELLINGTON’S £20m FOOTHILLS MOTORWAY

(From the Ministry of Works) The first section of Wellington’s £2O million foothills motorway is expected to be open by December this year. The motorway works now under contract have firm completion dates.

The £3,500,000 Thorndon overbridge contract (Wilkins and Davies, Ltd.-Taylor-Woodrow, Ltd.) consists of two threelane bridges each 4600 ft long, with on and off ramps. The bridges are pre-stressed concrete spans resting on umbrella-type girders, each weighing 350 tons. One of the umbrella girders is illustrated above. The ramp will be of continuous pre-stressed concrete box-girder design.

This contract has three distinct stages, each with its own completion date. Stage I will allow the motorway to be opened from Ngauranga to Aotea quay by December this year. Stage II will extend the motorway over the railway yards and Thorndon quay on half the bridge width and allow motorway traffic to enter and leave the city at Molesworth street. The target date for this stage is December, 1968. Taylor-Woodrow, Ltd., is a British firm with world-wide engineering experience and, with Wilkins and Davies, built Auckland international airport under Ministry of Works supervision. The completion date for the Ngauranga interchange being carried out by Downer and Company at a contract price of £186,000 is September this year. This involves the final three-level structure required to complete the motorway interchange at Ngauranga. The Ngauranga stream will be at the lowest level, the traffic interchange at the intermediate and the motorway at the top. Hobson Street Bridge Traffic from Ngauranga Gorge will not be able to use the motorway until the major overbridges are built across the Hutt road at Ngauranga. These will not be constructed until the foothills motorway is completed well Into the heart of the city. The other major structure now under way is the Hobson Street bridge which will provide access across the motorway. It should be finished by July this year. The contract price is £55,000 and the contractors the Williams Construction Company. This bridge is at the gateway to the city and will be the first over the motorway. No final dates have been set for completion of the foothills motorway. The future plan provides for the motorway to be extended from Ngauranga along the Hutt road to the Hutt Valley. Considerable progress has already been made on improving the existing highway along the western Hutt road. How the foothills motorway will affect motorists, and how they will will benefit, depends on their points of departure and destinations. Suburban Access Many of Wellington’s traffic problems are associated with the volume from the Hutt Valley and the west coast But the motorway is needed to relieve Wellington surburban access difficulties and vehicle movements within the city. By-passing the central area will relieve the business section of the city of some of the present congestion, which is at its worst at peak periods. The main southern terminal of the foothills motorway at Te Aro will lead into an area which is being redeveloped for commerce, industry and high-density housing. This redevelopment is being planned in conjunction with the motorway and it will eventually be given considerable impetus by the improved vehicular access. The blending of the motorway with the town planning of the whole city has been one of the major difficulties in the functional design of the over-all redevelopment scheme. The study made by ,4

the Wellington City Council's American consultants, de Leuw, Cather and Company, helped solve this integration problem. Roading Problems Wellington's difficulties are not peculiar to its topography, or to planning which had its origin in London in the horse and carriage era more than 100 years ago. As with most cities in the world, other than “start from scratch” capitals like Brasilia (Brazil) or, nearer home, Canberra, the existing reading pattern and arterial outlet system were not designed to serve highspeed vehicles for function, capacity or operational purposes. The centre of the city was established on the lower slopes and reclaimed areas between The Terrace and the waterfront. The higher range of hills to the north has been a major roading problem since the earliest days of settlement. The road between Wellington and Petone presented worse problems, relatively speaking, in the mudtrack, bullock-drawn dray days than it does now. Today’s four-lane Hutt road follows the foreshore alignment between Wellington and Petone, with a major intersection at Ngauranga which serves the four-lane motorway through the Ngauranga Gorge to Porirua. From here a twolane highway continues along the west coast close to the settled areas which house hundreds who travel by car to Wellington to work and, at Ngauranga intersection, link with traffic from the Hutt Valley to create the first peak-hour bottlenecks of the day. These are repeated at the close of the working day and other busy times. Relieving Congestion It was apparent at least 15 years ago that the rapidly increasing traffic would cause congestion on the highway into Wellington. The Ministry of Works, whose roading division provides engineering and administrative services for the National Roads Board, then made a detailed investigation and feasibility study. The objective was a solution which would meet the position for many years. The outcome was a start on creating a foreshore reclamation to improve the situation on the Hutt road. The reclamation was formed by placing, compacting and stabilising material excavated from the hills near the Ngauranga intersection. The side slopes, or batters, of the excavation on the Hutt road side were terraced and grassed and will later be given further treatment to conceal scars where seed has not already taken. Beautification will follow in time as a normal part of National Roads Board and Ministry of Works policy. Already, along the Hutt road near the Ngauranga Gorge, thousands of succulents have been planted in crib walls which form part of work connected with the Ngauranga interchange. Thousands more will be planted. The excavated material from the hills was carted to the foreshore over a Bailey bridge built by New Zealand Army Engineers. This bridge has stood up remarkably well under the strain of the heavy loads which today form the foundation for the foreshore section of the motorway. After the study by the Ministry of Works, the Wellington City Council engaged de Leuw, Cather and Company to make a comprehensive transportation survey and plan to meet the city’s present and estimated needs and to study and recommend a proposed alignment of the motorway within the city : proper. I After an extensive study

based on traffic survey figures and modern roading evaluation principles, de Leuw, Cather and Company reported in August, 1963. The report recommended the foothills motorway route as practicable and economically justified. “Foothills motorway” is an apt name, as the proposed route skirts the foothills around the business area of the city and into the Te Aro Flat redevelopment area. The description also distinguishes the route from the “waterfront motorway” which would, the consultants considered, have many features to which strong objection could be taken. It is not being proceeded with. As the name suggests, it would have followed the line of the waterfront. Sources Of Traffic The need to extend the foothills motorway beyond the northern entrance to the city, at Thorndon, has been questioned. The figures determined by de Leuw, Cather and Company showed that of the traffic entering the central area 40,000 vehicles a day (40 per cent) came from the north (the Hutt Valley and the west coast), 30,000 (30 per cent) from the southern and eastern suburbs and the remaining 30 per cent from the other suburbs, among them Karori, Northland, Kelburn and Wadestown. - The figures indicated that the foothills motorway would serve and be travelled over by a large proportion (up to 70 per cent) of all vehicles travelling to and from the city and within its confines. In 1965 the National Roads Board asked the Wellington City Council to reaffirm the council’s approval of the foothills motorway from Ngauranga to Taranaki street. The council sought the advice of Professor Robert T. Kennedy, professor of town planning at Auckland University. His conclusion was that one or more new; relief high-capacity highways around or in the central area would seem to offer the only major and practical solution to the central area congestion. He largely agreed with the findings of de Leuw, Cather and Company. The council then reaffirmed its approval. Route Through City The foothills motorway as finally planned and now being built is, first, an extension of the reclaimed foreshore (Ngauranga - Aotea quay). Then, from near the Cook Straight ferry terminal at the west end of Aotea quay the motorway will continue on a viaduct over the railway yards, over Thorndon quay, under Hobson street in an open cut which is largely along the line of the disused Hobson street gully and along an alignment parallel to and south of Tinakori road to Hill street. Interchanges and ramps will be constructed at Aotea quay, Molesworth, Hill, Bowen, Boulcott, Vivian, Ghuznee and Taranaki streets. Beyond the Boulcott street interchange the motorway will descend into a tunnel section 1500 ft long and then under Vivian and Abel Smith streets and turn east towards Taranaki street. De Leuw, Cather and Company estimated the total cost of the foothills motorway at around £2O million. Roads Board Will Pay The National Roads Board has accepted financial responsibility for the whole project from Ngauranga through to Taranaki street. The future construction programme depends on how much it can :inake available each financial ; year. j The motorway is a direct ' charge on the National Roads

Fund. This now has a total revenue of about £36 million a year from petrol, mileage (diesel) and tyre tax, motor registration, licence and heavy traffic fees. Counties get 26 per cent of the fund’s net income, municipalities 14 per cent Highways are allocated 49 per cent from which come motorway finance. The board may also allocate part of the 11 per cent remaining. The percentages are determined by law. Land acquisition for the motorway is a big problem, handled by the land purchase section of the Ministry of Works.

Run-Down Area The purchase of about 400 properties is involved in the Aotea . quay-Taranaki street section .of .the motorway. Negotiations are complete, or under way, for half of these. Many of the properties are very old and would be, motorway or not, earmarked for demolition in the not distant future. These acquisitions are an inevitable part c f major city modernisation anywhere. Statistics show that over the last 20 years there hat been a marked loss of population in the areas through which the motorway will pass. This decrease has resulted from commercial and industrial growth and the extension of the business area of the city at the expense of the old and largely run-down residential area. A committee of Ministry of Works and City Council officers deals with problems of hardship to those whose properties are affected by the present construction. Alternative accommodation is offered, where required, and assistance with resettlement. The National Roads Board has now decided that before it accepts motorway projects it will first ensure that the local authorities through whose .areas the motorway will pass are taking adequate steps to house those persons affected who are unable to make alternative arrangements.

Cemetery And Memorial Some places in which the Wellington public has a deep interest are affected by the foothills motorway. One is the lower (The Terrace) end of the Bolton street cemetery. A scheme has been approved which could provide more convenient pedestrian access to the cemetery grounds and be aesthetically pleasing. Another is the national war memorial carillon and Hall of Memories, below the Dominion Museum. A further study by de Leuw, Cather and Company shows that a reasonably adequate area in front of the carillon and hall can be retained. Though it is possible to extend the motorway from Taranaki street to avoid serious disruption of the Basin Reserve, alternatives adjacent to this sports ground are being investigated. Detailed planning in this area has not been completed. The ultimate plan is for the motorway to link up with the Mount Victoria traffic tunnel. Another parallel tunnel adacent to the present one is planned and further upgrading of the suburban streets will provide an excellent vehicular route through to the already wide Cobham drive and on to Wellington Airport. It has been argued that an underground railway into the heart of the city from the north would be a more satisfactory solution than the foothills motorway to the traffic problem. But the findings of de Leuw, Cather and Company already show that both the motorway and the underground will be essential to the future development of the city. In fact, they are complementary and with both, and Wellington Airport, the capital would be one of the best anywhere in its transport and communications setup.