$201m motorway extension nearly ready to take traffic

Motifs on the Mt Roskill motorway extension are designed to reflect the terrain's volcanic characteristics. Photo / Richard Robinson.

More than 50 years after the route was designated, final touches are being applied to Auckland's $201 million Mt Roskill motorway extension.

Traffic will start using it in less than three weeks.

The 4.5km extension between Hillsborough and Owairaka - a central piece of the region's western ring route - is to open in stages over several days from May 15.

That will be preceded by an open day on Saturday, May 9 so residents can inspect features such as the six bridges over the motorway and urban design motifs reflecting the volcanic characteristics of the difficult terrain through which it passes.

These will include replica basalt mouldings under the Dominion Rd interchange bridge, at the motorway's mid-point, where Transport Agency engineers spent 18 months redesigning an on-ramp to soften its boundary with the Roskill mountain.

However, questions have arisen over the affordability of a 360m section of a foot and cycle path yet to be built between motorway and mountain.

The agency has built a concrete path along the rest of the motorway for Auckland City for $1.2 million, but the council is reviewing the mountain section against a cost blowout to $2 million for the 360m.

That is its estimate for meeting Environment Court conditions aimed at preserving the cultural and heritage values of the slope, but city transport chairman Ken Baguley revealed yesterday that officers were "revisiting" the project to find a less costly solution.

He said the council still hoped to complete the project in the next financial year, and would continue to recognise the area's cultural and heritage significance in working with interest groups to achieve the best result for them and city ratepayers.

Roskill Community Board chairman Richard Barter said he was disappointed the cycleway would not be ready for the motorway opening, as an important link in a 7.5km network of off-road paths already built between Keith Hay Park and Owairaka.

But veteran city councillor for Mt Roskill Graeme Mulholland expressed confidence the missing link would l be built.

He acknowledged congestion was likely to move to the end of the motorway, along Tiverton and Wolverton Rds, where the council has run short of money to complete a $22.5 million widening project before 2014.

But despite funding uncertainty also over the $2 billion-plus Waterview motorway extension, for which the Government is reviewing the economics of building tunnels, Mr Mulholland was convinced it would give motorists a clear run through Mt Roskill to the Northwestern Motorway.