Adelaide’s traffic congestion has been steadily increasing over the past decade, and there’s no indication that this trend is going to end.

Our response as a city, with a few exceptions, has been either to bury our head in the sand or blame delays on everything but the obvious problem – there are too many cars on the roads.

Last week, a comprehensive and sensible examination of the problem by a local planning consultancy was sunk by a debate about one of the outside options they put on the table – a congestion tax.

Meanwhile, the Property Council and its fellow travellers continue a one-note campaign against the State Government’s poorly sold car park tax.

The general views seems to be that Adelaide doesn’t have a congestion problem or, if it does, it is entirely due to crazy new-fangled ideas like bus lanes,  bike lanes and price signals.

Both views are wrong – and will cost us dearly in the long run.

We either address the problem sensibly, or face the prospect of creating an unliveable city.

The turning of the screw

The RAA’s surveys of travel times show that, like a frog in a slowly heating pot, Adelaide might end up being cooked by congestion before we’ve even properly recognised the problem.

It’s latest survey shows that over the past decade travel times have gradually increased. For inbound trips during the morning peak, Adelaide motorists are taking an average of 2 minutes 43 seconds longer than 10 years ago. The afternoon peak figures are very similar – these trips are taking an extra 2 minutes and 53 seconds.

The change is large enough to be annoying, but not quite inconvenient enough to encourage us to consider changing the way we manage our city.

As a recent report on traffic congestion by planning consultancy InfraPlan points out, the bad news is that once a city reaches near-capacity levels on the roads, congestion and travel times begin to rise exponentially as you add more traffic.

The Government’s 30-year plan envisages that the local employment base could grow by 50,000 workers by 2038 – which is a possibility given the city grew its population at twice that annual rate in just a decade. That would mean about 42,000 more car parks and 84,000 more car trips in and out of the city.

“That could not happen without peak periods being in constant gridlock for up to two hours,” InfraPlan warns.

Like most Adelaide policy-makers and decision-makers, the RAA’s solution is basically to build bigger and better roads. The Property Council’s sole idea seems to be – don’t have a car park tax.

But there is another way – a comprehensive solution – as outlined by InfraPlan, which deserves closer consideration.

What won’t work

InfraPlan argues that a push to increase city car parks and wind back the number of bus and bike lanes in Adelaide’s CBD would be “a disaster for the city economy and social well-being of its residents”.

Its discussion paper points to one central conclusion – Adelaide needs to reduce its dependency on cars.

The city’s relationship with car commuters has become the focus of political attention, with city councillor Mark Hamilton launching a campaign for the lord mayorship based on a platform of limiting bike lanes, removing bus priority lanes and building new car parks.

The InfraPlan paper attacks this agenda head-on.

George Giannakodakis, managing director of InfraPlan, said input from transport and urban planning professionals in the city transport debate had been “conspicuously absent”.

“The city of Adelaide supports a heavily car dependent metropolitan workforce, in fact one of the most car dependent in the western world,” he said.

“This is largely driven by it having some of the cheapest and most plentiful car parking (70,000) compared to other cities (Adelaide’s is up to 300% cheaper and has 300% more parks per 1000 employees when compared to Sydney). This may explain why it is the most car dependent capital city in Australia and one of the most resilient to change.”

Remove/redirect ‘through’ traffic from the city

About a quarter of the city’s traffic – or 55,000 car trips out of a daily total of 220,000 – use the city as a convenient through route.

Surprisingly, many of these trips are made by inner-suburban residents – not those who live further out.

The solution includes fixing Adelaide’s ring road, but that so far elusive task must be accompanied by other measures including stemming falling public transport patronage, and encouraging more people to cycle or walk.

If Adelaide wants to sustain the rate of car dependence that it has enjoyed for the past four decades, “it has to be prepared to accept the consequences”, InfraPlan warns.

And these consequences would be very ugly indeed for the character of Adelaide’s inner suburbs.

“This includes a return to the road building program of the 1980s to widen several inner suburban key roads and established main streets that lead into the city. Current urban design principles to return the road reserve to main street activity would be compromised. One would suggest this would be a dividing community issue.”

Just quietly.

Reduce city workers’ car dependence

The biggest impact on city traffic congestion comes from the 120,000 workers who converge on the city each day, half of whom use a car.

This is very high by Australian standards. ABS stats show that 49 per cent of us travel to work by car – this compared to 40 per cent in Melbourne, 38 per cent in Brisbane and 18 per cent in Sydney. Even car-loving Perth has a rate of 45 per cent, significantly lower than Adelaide.

One of the factors encouraging all these drivers is Adelaide’s car parking – the cheapest and most plentiful by far of the major capitals.

Adelaide has 244 off-street car parks per 1000 workers – way ahead of every other Australian city.

“Cheap and plentiful car parking may work for a suburban shopping centre but it is a significant challenge for a growing capital that needs to cater for a growing resident, employment and student base. Adelaide simply cannot continue to develop and provide even more cheap car parking without driving city streets to a point of gridlock,” InfraPlan says.

In fact, traffic engineers would have expected Adelaide to be in much worse shape by now, given the increase in city population – but increased rates of cycling and walking have kept gridlock at bay.

The roads have a finite capacity – the answer is to use the space better.

Move more people than vehicles

There are only three options for reducing congestion – widen roads and build freeways, find more efficient ways for move the same amount of people, or a mix of both.

One bus can replace up to 30-40 cars and one tram up to 150-300 cars. Four bikes take up as much room as one car.

All of these options actually free up space on the roads for cars.

It should be a no-brainer.

InfraPlan argues that before the Currie/Grenfell street bike lanes were introduced, the corridor catered for up to 85% of its traffic in cars, which moved only 25% of the people. It wasn’t efficient and, without a bus lane, congestion was about to get a lot worse.

Bus and tram lanes are “essential”, but “Adelaide appears to be defying the (global) trend with its reaction to bus lanes”.

“This may come back to how ingrained car dependency really is in Adelaide, driven by factors such as the ability to access cheap and plentiful car parking.”

Promote and fund public transport

Planning and investment needs to shift towards developing a transport network to cater for an increased number of people movements.

InfraPlan argues that private car travel has a significantly greater infrastructure impact on cities compared to buses, bicycles and pedestrians because it requires more road space (widening roads) to move a smaller number of people (as most car trips to the city involve single occupants).

In summary – increasing public transport use will ease congestion and reduce the expensive and potentially divisive options of widening inner-suburban and city roads.

Last year, the Government belatedly created a plan to modernise our transport system – including an O-Bahn tunnel and other improved bus infrastructure and a rebuilt tram network. The question now is how they will fund it.

Moving on

Whether we like it or not, Adelaide’s dependence on the car will come to a crunch.

The challenge for the debate in Adelaide is for everyone to lift their heads beyond a reductive debate about taxes or sectoral interests and look at the bigger picture.

If we don’t, the cost of the car park tax could be but a tiny proportion of what we will end up paying – economically and socially.

For the full InfraPlan paper, go here.