Auckland's billion dollar traffic problem cannot be resolved so long as there are seen as just two factions spouting the slogans: "complete the motorway network" or "no more motorways". Rather, each roading and public transport project must be assessed on its own merit. It's quite legitimate to be for one motorway and against another, and for reasons other than the standard nimby ("not in my backyard") reason.

I actually find myself in a reverse nimby situation, in that I favour a motorway that will eventually go uncomfortably close to my place of work (the completion of the south-western motorway), and I oppose one that will have little effect on me (the eastern motorway).

I must confess though that I'm not completely selfless on this matter. I live close to a long-completed part of the south-western motorway. I drive to work along roads - through Mt Roskill - that are close to the route of the penultimate phase of this motorway. This motorway will help me get to work. And, yes, I am implacably opposed to two of the three routes suggested for the final stage. One of these options will pass through the attractive and historic Unitec campus where I work. (Yes, historic; remember Oakley and Carrington Hospitals, New Zealand's answer to Auschwitz, places that should not be forgotten.) The second route follows Oakley Creek, with metro Auckland's loveliest waterfall, which is virtually a part of our campus.

Whatever route is chosen, there will be environmental costs to completing this motorway. But the environmental costs of not completing it are so much greater.

The argument about the desperation of Auckland's present problem is not unlike my argument about mortgage finance and house prices last week. I claimed that rising mortgage interest rates stimulate the demand for mortgages, and that the related rises in house prices effectively stimulate (in Auckland at least) the demand for housing.

It is equally true that the rising traffic congestion itself creates additional demand for car trips in Auckland. It works in two ways.

As the city centre becomes a less attractive place to work and to shop, people choose to go more to destinations in the suburbs. And these inter- suburban trips are the hardest to do by public transport. The traffic that is most damaging in this regard is the commuter traffic between the North Shore and destinations south (or south-east) of the sclerotic heart of Auckland.

The second way it works is that as we find that, as traffic has increased, the streets have become less and less safe (especially for children) from both traffic fumes and crashes. How do we protect our children from these dangers? Well we put them in cars; we drive them to school. And, if we get another National Government, we must expect a significant increase in the average distance in which parents will drive their children to and from school. (Auckland's traffic problem literally disappears in the school holidays.)

The completion of south-western motorway is required to release the city centre from the grip of traffic, most of which has no interest in the city centre as a destination.

Unfortunately, the route that the last stage of this road follows may be influenced by planners thinking not about this project but in another that is already in their dreams. It is the mooted third crossing of the Waitemata Harbour.

Now Auckland needs a third harbour crossing like it needs a hole in its head. (Come to think of it, the CBD is something of a hole in its head.) The present Auckland Harbour Bridge is not congested at peak times; the congestion is elsewhere. Part of the Auckland's solution must be to discourage people who work in the south from living in the north. A third harbour crossing will - at great expense - considerably aggravate this problem.

Routing the south-western motorway through Unitec makes no sense if the south-western motorway is what it should be; a link between the south and the west that provides a genuine alternative to the central city's 'spaghetti junction'. But the Unitec route probably makes the most sense to planners with ulterior motives; to planners who are more concerned to link the south-western motorway with a third harbour crossing to the west of the present harbour bridge.

Proposals for an additional road crossing of the Waitemata can play no constructive role in the solution of Auckland's present problems. Further, we have plenty of transit space for getting people from the North Shore to the centre of Auckland. We have a harbour. The harbour need not be a barrier; it should be, among other things, the highway that it was in Auckland's earliest days.

Say no to another harbour bridge. No to a tunnel under Grey Lynn. No to a tunnel under the Waitemata. Say yes to decent ferry services. Yes to the southwestern motorway. And yes to whatever it takes to enable parents to let their children walk or cycle to school.