The city is choking thanks to our idea of transport nirvana  

Ross Gittens has an article in the SMH about the recent Christie report on Sydney's public transport - The city is choking thanks to our idea of transport nirvana .

Building roads and neglecting public transport turns population increase into urban sprawl, with widely dispersed residences and jobs. This encourages more car use and, indeed, locks many parts of Sydney into dependence on cars.

Neglect of public transport causes a movement away from it, which is then reinforced by deteriorating service frequencies, service quality, travel times and even the cancellation of off-peak services. So we've had both pull factors (we prefer our cars) and push factors (reduced quality and availability) worsening public transport and compounding our problems.

The report says that ''even if it were assumed that private vehicle travel will continue to be as viable and affordable as today … adding to or extending Sydney's radial freeway and toll-road system would be an expensive way of providing at best very short-term and geographically limited improvements''.

And, of course, we can't assume car travel will stay viable and affordable. Our heavy dependence on car travel is unsustainable. Curbs on greenhouse gas emissions will force up its price, as will the growing shortage of world oil reserves.

Add the projected growth in Sydney's population - a 40 per cent increase to 6 million in the next 30 years - much of which will be accommodated by higher-density living, add the much higher proportion of elderly people, and you see why we need to switch to a different tram, as other big cities that have pursued road-based solutions are doing.

That still leaves a role for cars, of course. As the report says, not all of Sydney is dense, nor should it be. ''In lower-density suburbs, for trips not going into urban centres, the private car is likely to remain a dominant mode of travel,'' it says.

The challenges we face in getting our transport arrangements back on track are considerable and costly. We need catch-up measures to correct the under-investment in public transport infrastructure for the present population, as well as measures to accommodate future population growth.

We need extensions of the public transport system into outer areas as well as significant enhancement of the system in inner areas. This will leave little room for the building of further freeways or tollways.

We need more investment in all modes of public transport - rail, light rail, buses, ferries and even, well down the track, metros - but according to a carefully considered, long-term plan establishing a clear order of priority.

We need less rivalry and more co-operation and co-ordination between the modes so that an ill-fitting collection of systems becomes a single, seamless one. It's not possible for all journeys to be completed without the need to change within a mode or between modes. This requires integrated timetables, accurate and timely provision of information about disruptions and, above all, an integrated fare and ticketing system.

All of this will cost and there's no one to pay for it but us. There'll be carrots (more and better quality train and bus travel) and sticks (rising levels of road congestion for those who persist with cars).

But here's the good news: both the public's submissions to the inquiry and the inquiry's opinion polling show most Sydneysiders have got the message. Now all that remains is for light to dawn in the minds of our politicians.