Congestion

We all hate it and there's only one certainty about it: it's going to get worse. In fact, I'd suggest it's a mathematical inevitability. Things could be worse though: it could get better. Confused?

Nothing seems to infuriate the community at large more when it comes to urban growth than the consequence of rising traffic congestion. Getting to and from work and even shopping or recreational trips around the city on a weekend seem to take longer. We seem to spend more time stopped in queues of traffic waiting at traffic lights (often for two or three changes) before we move dutifully on to the next queue. Long-time residents recall fondly the days of easy mobility and, prodded by rising public annoyance, governments have rightly responded by approving new road initiatives to create more lane space.

In south east Queensland that's meant the inner city bypass, the Gateway duplication, the Clem 7 tunnel, the Go Between Bridge, the Legacy Way Tunnel, and the M7 Airport Link - all of which have been green lighted with the intention of improving mobility around the city. With the exception of the ICB, nearly all of these have been initiatives of recent years, spurred initially by then Lord Mayoral Candidate (and now Premier) Campbell Newman's 'Trans Apex' proposals. These won broad support at the polls from a community anxious for someone prepared to bite the bullet on doing something about congestion.

The 'new ways not freeways' brigade of flat-earthers, who had successfully scared off previous governments (witness the Goss & Beattie era opposition to virtually any new road projects), were out of favour.

But transport infrastructure investment wasn't just limited to roadways for private transport. Billions have also been spent on busways and the bus fleet. Rail has been upgraded, and new lines are under construction south west to Springfield ($1.3bn) and north east to Kippa Ring $1.14 bn). Billions more have been proposed on public transport projects we really quite like the sound of but can't afford. The $6 billion (or is it $7bn or $8bn?) cross river rail project is just one of those.

Yet despite this long overdue recapitalisation of our transport systems, congestion just seems to be getting worse. And there are very good reasons why it will continue to get worse. Why?

For starters, a city that grows is bound to experience more congestion. More people will equal more congestion. And when city plans are predicated on creating more urban density by increasing the number of people per square kilometre, congestion will get worse, faster. This is simple maths and it's virtually impossible to deny. If there are 'experts' in urban planning trying to convince you otherwise, I'd suggest you think very carefully about the snake oil they're trying to peddle.

The only way a city with rising density could avoid more congestion would be for every single extra person who is accommodated in a high or medium density dwelling to solely and exclusively rely on public transport, and not own or need a car, for anything. Either that, or we expand our road networks and public transport systems at a rate many times the scale of what we've already been doing, which we simply can't afford (and indeed, just finding the space for the extra road lanes or rail lines is a physical impossibility in an already urbanised area, without going underground, which is massively expensive given our relatively small urban populations).

The reality is that even at the highest rates of public transport use on a global scale, you are not going to get more than half the population using public transport, or walking or cycling or staying at home. The other half will need and will use private transport and so will add to congestion.

But as targets go, 50% is well beyond the realm of possibility: it's plain fanciful. This (50%) is the level of public transit in New York, famed for its subway system, mega density, and very large population (over 8 million). There are few cities like New York on the planet. And even by US standards, it's unique in public transit patronage.

So for Australia, the most optimistic hope is that maybe, at the best, 30% of the extra population in higher density housing won't need or depend on a private vehicle. That in turn means that roughly 70% will. So for every extra 10,000 people you add into existing urban areas under a density model, you will generate roughly 7,000 more people relying on something other than public transport to get around. Overwhelmingly that is the private car.

You could always hope and pray that a high percentage of the existing population in established urban areas will swap their cars for public transport, alleviating road congestion in the process. You could also believe in Peter Pan. Here are a couple of neat little graphs which show long term patterns of public transport patronage in Australia.