KEY POINTS:
Transport Minister Steven Joyce brought some bad news for Auckland yesterday. The last link in the western ring road, a tunnel proposed under Waterview and Avondale, is now reckoned to cost $2.77 billion, nearly half as much again as an earlier estimate. It would be an inordinate share of the national roading budget to spend on a 4.5km stretch, six or nine times as expensive as comparable lengths on the surface, and the minister has asked for alternatives.
Oddly, none of the alternatives his ministry will investigate include moving the connection from Waterview, on the western edge of the isthmus, to the Rosebank Peninsula, the route favoured by the Auckland Regional Council. That may be a marginally longer connection to the new motorway at Mt Roskill but it would appear to offer less disruption to residential neighbourhoods than a multi-lane motorway through Waterview.
The Rosebank route, if it followed the shoreline, would threaten only marine life. If that is no problem for the ARC, it ought not to trouble the Transport Ministry. Mr Joyce should widen his re-assessment of the project. He has at least widened the envisaged tunnel.
The previous Government was contemplating twin tunnels of just two lanes each way, which sounds like the original Harbour Bridge without room to clip on the extra capacity it needed within a few years. If the western ring link is to be underground he wants three lanes in each direction, which raises the likely cost to more than $3 billion.
Just the two-lane cost estimate is equivalent to about 1.6 per cent of New Zealand's GDP. Even by the standards of economic stimulants currently under discussion, the Waterview tunnel costs are out of all proportion. The cost-benefit equation barely breaks even and - most tellingly - the tunnel is reckoned unable to support a $2 toll.
If even that token contribution to the tunnel's costs would cause too many motorists to divert to surface streets, the need for the link must be questioned. Aucklanders possibly do not see the benefits that transport officials predict in a motorway around the western edge of the city. It seems a circuitous route from the North Shore to Auckland Airport, though officials are certain it will attract that traffic.
In any case, the ring is mostly built now and the last link should not be delayed. To quote the head of the Council for Infrastructure Development, Stephen Selwood, yesterday: "Completion of the Waterview connection is central to releasing the full value of the corridor... It will provide significant economic stimulus to West and South Auckland, and is central to lifting productivity across the whole of the Auckland region."
The project already has been seven years in gestation and we had been given to expect its completion by 2015. The latest re-evaluation of alternatives may take a few months and if the tunnel does proceed, its finishing date would now be mid-2016.
The principal alternatives for the connection would be a "cut and cover" construction, which would bury the road fully or partially after clearing a swathe through Waterview's housing, or an "open cut", which sounds worse. In the name of all reason, Mr Joyce should send his officials back to Rosebank where a path could be laid through mainly industrial areas.
Nothing is to be gained from a stretch serving Waterview, particularly if it is underground. Travellers from that part of the isthmus can easily enter the motorway at Avondale or Mt Roskill.
Auckland's transport planners can suggest more worthy projects that would come at a third of the cost of this extravagant underpass. It's gone.
