It was to Len Brown's credit that h' />

It is already apparent that Auckland's first "super mayor" will be haunted by three ambitious rail projects.

It was to Len Brown's credit that he stood for something constructive in the election campaign; his main rival might ponder whether the result might have been closer if he had stood for something more exciting than rates control. But having pinned his colours so confidently to costly schemes, Mr Brown's problems are just beginning.

The Prime Minister's response is the first of them.

"There is no free lunch when it comes to any of this stuff," he said on Monday. The Government already had $5 billion of transport projects for Auckland under way, $1.6 billion of it for new passenger trains, electrification and double tracking of existing lines. If Mr Brown wanted to build new lines ratepayers would have to pay a "fair share".

The warning could not come too soon, though Mr Brown thinks it premature. Discussions on paying for rail projects would take place over years, he replied, not three days after an election.

The discussion had better not take years, not if he is to show much progress on an inner city loop, an airport connection and a North Shore line before he next faces the voters.

The mayor and the left-leaning majority on the new council need to quickly agree on some financing proposals that might entice the Government to support the projects.

Once they have a rough idea of the ratepayers' likely share of the cost they could start the task of selling the proposition to them. That will be a much harder task than it was in the election campaign - proposals without a price tag are easily applauded - but not an impossible one.

Aucklanders could be convinced that a train-to-plane service, for example, saving them the long drive to the airport, could be worth the cost.

The mayor could point out the savings in the airport's grossly expensive parking charges or in taxi fares from most parts of the city. Those costs are known, once the ratepayers' contribution to a rail connection can be estimated we can have a practical discussion.

Likewise, an inner city loop, which Transport Minister Steven Joyce thinks is the only project of the three worth serious consideration.

The loop, under the western side of the CBD, would give Auckland something of a subway, a metropolitan status symbol that might entice Aucklanders to patronise it. A good mayor might convince citizens it is worth the cost.

A North Shore line would be a more difficult proposition. Only one section of the city would benefit and even Shore commuters might question the benefit of converting their new busway to a rail.

Buses can leave the expressway and take them closer to home. But a harbour tunnel for rapid transport in either mode could be a winner.

The new city leaders have the example of the harbour bridge to show them that Aucklanders are willing to pay for infrastructure that is clearly worthwhile. They paid for the bridge with tolls, which is probably not a realistic proposition for rail schemes. Ratepayers will have to be persuaded to pay for them.

They will not be persuaded by devices such as infrastructure bonds and public-private partnerships, which Mr Brown presents as alternatives to taxes or rates.

Bonds and "PPPs" are fine methods of testing the value of public investments but they still carry public costs, either as interest on bonds or charges by private partners.

The Prime Minister has challenged the new mayor and council to put Auckland's money where their mouth has been.

Unless they do so their schemes will remain idle pipe dreams failing to tap the city's newly constituted possibilities.