The Labour Government's plans for light rail in Auckland have come under fire from an elder statesman of the party, Sir Michael Cullen.
In his last two columns in the Weekend Herald, Cullen has raised concerns about the enormous cost and disruption of light rail and suggested electric buses are a better solution.
"It looks like an idea whose time has passed," said the former deputy prime minister and finance minister when talking about light rail.
Cullen has also taken a pot shot at supporters of light rail, saying they have airily dismissed the enormous cost and disruption as of little consequence and arrived at the solution before adequately analysing the problem.
His comments come as new Transport Minister Michael Wood tries to get light rail back on track following a convoluted process last term, which was blocked in the end by NZ First, whose leader Winston Peter said it could cost between $10 billion and $15b and lead to a "decade of chaos".
Wood has said light rail is the largest and most complex infrastructure project in New Zealand. It is a flagship policy for Labour, promised by Prime Minister Jacinda Ardern at the 2017 general election.
In April this year, Wood formed an establishment unit to come up with the mode, route, costings and financing options for Cabinet to consider later this year.
The Herald understands the unit has gone back to first principles and is looking at about 15 options for rapid transit in Auckland, including buses and heavy rail.
Cullen said it is hard to find what the underlying rationale for light rail now is, saying originally it seemed to be about moving people quickly to and from the airport into town.
"Then it became more about accelerating intensification or urban development along at least the first half of the route," he said.
Cullen, a former AT board member, said there are two key aspects to Auckland's transport woes - congestion and high levels of carbon emissions by private cars.
Encouraging electric vehicles(EVs) could increase congestion, he said, but also made it more important to invest heavily in a public transport network that fits how people move around in Auckland.
Buses, preferably multi-car electrified operating on dedicated bus lanes and free, will be the backbone of Auckland's public transport network for the future, said Cullen.
He said he had been told the main problem with electric or hydrogen buses is they are too heavy for Auckland roads, but this seemed a bit strange given the city is committed to an electric bus fleet.
"If true, it only highlights the need to progressively upgrade the potential routes - surely a cheaper, more flexible and more efficient option than trying to create the full light rail network which some dream of," he said.
It is not clear what a $10 billion-plus tram line will add to a bus network, said Cullen, saying nobody can make the light rail project have a positive benefit-cost ratio, whatever heroic assumptions about inner-city redevelopment are made.
Wood said he was always interested in the views of the "highly respected" former Labour minister and deputy prime minister and planned to drop him a line, have a chat and give him the full context of light rail.
The new minister said the rationale for light rail has been thoroughly examined by multiple agencies and reports, saying the only change by the current Government is to ensure value for money.
On the issues of buses, Wood said the central city is already close to bus congestion and more bus services will undermine the network.
"Buses, while continuing to play a core role in the network, simply cannot compete with the capacity and frequency of light rail, which has the ability to take 300 to 400 people per unit.
"For an enhanced bus service to be effective would require its own dedicated lanes, which, in itself, would be highly complex, expensive and disruptive to construct," said Wood.
Last month, AT released a new City Centre Bus Plan, which says even after the City Rail Link and light rail are built, most public transport journeys into the central city will still be by bus.