Key Points:

An ambitious Auckland road-widening project to cope with extra traffic from the motorway extension ploughing through Mt Roskill faces a long interruption because of council cost-cutting and staff shortages.

Auckland City chief executive David Rankin has blamed a shortage of transport planners for a recommended delay to the $17 million project between the end of the motorway extension and New Lynn.

But transport planning group manager Allen Bufton said last night the project was not regarded as essential until 2015 to 2020, making it a candidate for deferral in a round of cutbacks ordered by the new council.

Although the council this year finished widening a difficult section of Tiverton Rd in New Windsor for $3 million, it is likely to defer the rest of the project between Maioro Rd and New Lynn in a new budget determination in February.

The next stage of the project, including widening Wolverton Rd and the rest of Tiverton Rd to four lanes, was to have started next year, before Transit NZ's completion of the 4km Mt Roskill motorway extension in 2009 for $195 million.

Mr Bufton said the project either had to be completed before the Rugby World Cup, or left until afterwards, as the worst thing would be to have a half-finished job disrupting traffic during the event.

He said congestion in what is a key route to Waitakere City was expected to remain within acceptable limits for some years after the motorway opened.

Even so, expectations of higher traffic flows through New Lynn from the motorway were key to Waitakere's success in persuading the Government to spend up to $120 million next year sinking a double-tracked railway line through 1km of the town.

Transit also hopes to extend the motorway even further - to Waterview - by 2015, taking pressure off the Tiverton route. Mr Bufton said road-widening could also allow bus priority lanes to be built.

The completed first stage of the project involved building two large embankments to widen Tiverton Rd between Whitney St and Blockhouse Bay Rd to two lanes in each direction.

Although Transit will widen Maioro Rd from the end of the motorway, the delay will leave New Windsor Rd with just one lane for westbound traffic trying to reach Tiverton Rd.

Mr Rankin said Auckland City had at least managed to boost its transport "infrastructure delivery" staff numbers, after a heavy reliance on outside contractors seriously weakened its project management capability. That led to a $13 million blowout on Greenlane roading improvements which are now expected to cost more than $32 million. But it needed more planning staff to lay firm foundations for future projects.

A council review of Project Greenlane blamed "multiple systems failings" within and outside the council for the cost blowout.

But it identified poor project management as the single biggest failing before lines of accountability were tightened this year, handing sole responsibility to a new group manager for transport infrastructure delivery.

Although the council is refusing to release a full audit report on the debacle - citing issues yet to be resolved with management contractors - it has produced an abbreviated document disclosing a "dysfunctional" relationship between planning and delivery arms of its transport division before they were reorganised under a single general manager.

The document referred to "deep-seated animosities" and confusion over who in the council was primarily responsible for managing the project, to the point that each of the two arms thought the other was in charge.

Mr Rankin expressed confidence that the project was now being well-managed towards a completion date next June, nine months later than first planned.

The project

* The route: End of the Hillsborough motorway extension to New Lynn.

* The cost: $17 million.

* The delay: Until 2015 to 2020.