Beyond "peak car": Why Australia's traffic projections are almost certainly wrong

Rush hour traffic in Melbourne. Image: Getty.

Most mathematical modelling used to guide our economy is simplified and only modified when it becomes so out of touch that it is dangerous. When the Atlantic cod fishery collapsed, the model being used to set fishing quotas was still suggesting the fishery was healthy. In retrospect it seems a kind of madness to have kept using it.

Traffic modelling in Australia is now similarly out of touch. A recent study by the Bureau of Transport Industry & Resource Economics modelled the future of traffic in Australian cities. If it had been a mere academic study it would not be dangerous, but it is now being used to justify massive road spending.

The report suggests that travel times will blow out and road congestion will cost the economy more than A$50 billion. Congestion, it seems, is out of control and will engulf us all, with terrible economic consequences for Australian cities.

Modelling relies on heroic growth assumptions

In order to reach these numbers the report had to make assumptions about growth trends in car use per capita. The high-growth scenario is included in the red box below.

Traffic modelling shows a sudden reversal in car use from the clear trend in Australian cities over the past decade. image: BITRE/author provided.

As is common in such modelling, a low-growth scenario is also modelled and then the future is taken to be in the middle.

The high-growth scenario can be seen to reverse a trend in car use per capita that appeared to be well set after a peak in 2003-04. This peak car phenomenon has been found in all developed cities, and has been analysed by many commentators including ourselves.

Understanding the peak car phenomenon would appear to be a basic requirement before attempting future scenarios that wipe it out completely. However, this report has not ventured into such questions. Instead, it continues the methodology used for the past 30 years.

Travel time reality means car use has peaked

The fundamental problem is that the model does not understand how cities work. Travel time is seen as something that just expands as our cities of car-dependent suburbs grow outwards.

However, the Marchetti travel time budget of just over an hour on average has been found to apply universally across all cities. Some people can go beyond an hour and some much less, but the average everywhere is an hour. This has been found over and over to apply in every city.

If people find it hard to live with so much time “wasted”, they move to somewhere more within their travel time budget. If the overall options in housing, jobs and travel become so dysfunctional that people are forced to travel beyond their time budget then the issue becomes highly political: elections are fought over infrastructure and housing options. Cities adjust; they don’t keep expanding travel time.

It is possible to understand the global peak car phenomenon in terms of cities hitting the Marchetti wall. In our data, cities everywhere began to grow in their traffic congestion whether or not they built freeways or extra road capacity. This was because these just filled very quickly.

Rail projects unclog the urban arteries

Rail projects, however, could go around, over or under the traffic. Hence, over the past 30 years, rail lines have become more travel-time-efficient than traffic arteries. Many people, especially the young and wealthy, began to move back into areas where public transport was well provided.

The rejuvenation of central and inner areas is not just because they are cool and trendy, but because they offer reduced travel time. Car use per capita goes down when there is less need to travel, especially by car.

With fixed road capacity, traffic volumes stay constant

This model does not consider this to be significant enough to consider in forecasting scenarios for Australian cities. It crudely projects a totally car-based-and-growing set of futures. It barely considers the remarkable global turnaround in the building of rail systems and the rejuvenation of cities.

Scenarios where these urban trends are considered to continue (rather than suddenly dying as suggested bythe chart above, followed by inevitable growth in car use) would make much more sense. This is the way planning is being done in cities like London.

The evidence in London and other cities – with good public transport alternatives and competitive door-to-door journey times – is that, with fixed road capacity, traffic volumes stay constant (or slightly decline). All the growth goes on to public transport and the car-based share of travel falls – down from 46 per cent for residents of London in the 1990s to 32 per cent now.

The scenarios for London are therefore all about how best to build public transport and land-use options that can enable economic growth to occur sustainably, rather than trying to increase road capacity. Similar considerations can be seen to be happening elsewhere around the world.

Did an ‘Abbott effect’ skew the modelling?

The modelling work dates back to when prime minister Tony Abbott was all about building roads and wouldn’t fund rail. Image: AAP/Dan Himbrechts.

So why have we in Australia refused to change our modelling and are still trying to justify massive road capacity increases?

Traffic modelling reports like this take about two years to produce. What was happening around two years ago was the election of Tony Abbott with his commitment to spend some A$40 billion on urban roads and nothing on urban rail.

Huge road projects in Melbourne (East-West Link), Sydney (West Connex), Brisbane (Gateway) and Perth (Freight Link) were all announced before any assessment. Their rationale was very shaky and most of these projects have now either failed or are failing.

Each road project also has large impacts on their urban economies. These are dangerous as they destroy so much of the urban fabric necessary for rejuvenation and take away the ability of governments to pay for the more important urban rail projects on their agendas.

The upturn in the graphs in Figure 1 seems to be an Abbott effect. It is rather amusing now that this report came out just as Malcolm Turnbull took over and began talking up urban rail and urban regeneration.

Such models should be put into the museum and as a better sense of where our cities can be going. This report can be easily passed over – but if the thinking behind it stays, the impact on our cities will be very damaging.The Conversation

Peter Newman professor of sustainability Curtin University

This article was originally published on The Conversation. Read the original article.


How the rise of anti-crime politics caused lasting harm to Black Americans

"I see an awareness that has developed in the Black community in the last 10 years or so about how deeply racist the criminal justice system has become," James Forman Jr. says. (David McNew/Getty Images)

The police killing of George Floyd, and the protest movement that emerged from it, has reinvigorated a national conversation around reinventing criminal justice policy in the United States.

At the same time, reports that violent crime is rising in many US cities have resurrected talk of the much-disputed “Ferguson effect,” a theory put forward by law enforcement professionals, and some researchers, who argued that police slowdowns in the wake of the first wave of Black Lives Matter protests resulted in elevated rates of violent crime. President Donald Trump is trying to weaponise this narrative, paired with images of federal officers clashing with protesters in the streets of Portland, to wage a 1968-style backlash election campaign.

“People who want to mobilise a lock-them-up style of either policing or prosecution have tried to weaponise those short-term increases,” says James Forman Jr., professor of law at Yale Law School. “Criminologists will say you have to be very, very cautious about short-term movement [in crime statistics]. We don't know whether or not what we're seeing right now [with violent crime increasing] is going to sustain itself. But the fact is, it's here and people are talking about it.”

In 2018, Forman won the Pulitzer Prize in nonfiction for his book Locking Up Our Own: Crime and Punishment in Black America. Drawing on his experience as a public defender in Washington, DC, he traced the emergence of anti-crime politics in late 20th century Black communities. Forman showed how newly empowered Black politicians fought for policies they believed would protect and uplift Black Americans, but inadvertently contributed to mass incarceration. 

CityMetric recently caught up with Forman to discuss crime trends, where he sees reason for hope in this moment and how the Black political class’s attitude toward crime and punishment has shifted since the latter part of the 20th century. 

This interview has been edited and condensed. 

There is talk right now about a resurgence of crime and violence in American cities. We saw similar, more localised concerns after the initial 2015 Black Lives Matter protests in Ferguson and Baltimore. Do you fear this could reinvigorate the kind of politics you describe in your book among segments of the Black community and political class?

I fear that it could be reinvigorated nationally and also in the Black political class. Look at the political conversations that are happening in Atlanta right now, for example, a city that also has seen a short-term uptick in crime as it is a site of a lot of protests about George Floyd and Breonna Taylor on the national level, as well as Rayshard Brooks and Ahmaud Arbery more locally in Georgia.

I think that you can already see in some of the language of the local elected officials this idea that we have to be very careful about pulling back. [They are saying] “while the protesters may make some valid points, we can't risk returning to the ‘80s and ‘90s.” Those decades really traumatised the United States, and particularly traumatised Black communities. There's a deep fear about returning to the levels of the violence that we saw in the crack years.

You write a lot about class divides among Black Americans, where middle income and elite Black people don't suffer as much from extremely punitive policies. They also have closer ties to the politicians who are creating these policies. There are very specific groups of people, even in marginalised communities, whose voices are heard.  As a result of these dynamics, you write about Black politicians fighting for things like mandatory minimum prison sentences or against decriminalising marijuana. Is there still that disconnect between those who suffer the most from criminal justice policies and those who are actually heard in political discourse?  

Let me just say a caveat, that when we talk about class divisions in the Black community it's important to hold two truths in our head at the same time. Bruce Western and others have shown the way in which class, educational status, income can dramatically reduce the likelihood of being hardest hit by the criminal system – namely incarcerated. Middle class and upper middle class Black people get some measure of protection. It's also true at the same time that Black people of all classes are worse off relative to their class counterparts in the white community. 

One area where class is least protective is policing and police stops. The police do not know how many degrees you have. They don't know how much money you have in your bank account. I want to be very clear that in making this point about class, I'm not making the argument that race or racism don't matter in this context. 

In terms of how it plays out now, I see an awareness that has developed in the Black community in the last 10 years or so about how deeply racist the criminal justice system has become. Twenty or 30 years ago they had a consciousness, but there's levels of understanding. Many of the people I write about in the book wanted to promote the interests of the Black community. They weren't motivated by indifference or callousness. When presented with mounting evidence of how awful this system has been in Black lives, they're reconsidering and recalibrating. 

Lots of former elected officials have said to me some version of “I didn't know at the time and I appreciate that you showed us in our full complexity. I appreciate that you showed the pressures we were under. If I had known then what I know now, maybe I would have been less quick to go along with some of these harsh measures.” 

The second thing that has affected the Black political class has been the emerging movements, led by Black people in particular and led by young people. They not only educated leaders, but pressured them and made them understand that there is a political cost. If you're not moved by the moral argument, then you'll be moved by the political argument. You'll be moved by the people protesting outside the office of District Attorney Jackie Lacey in Los Angeles, for example, where Black Lives Matter LA has held, I believe, a year of consecutive protests against a Black district attorney who has had really some of the worst practices.

From what I can tell, she's been pressured by the movement to change some of her positions on important issues like prosecution of low-level drug offenders, for example, and the aggressiveness with which she prosecutes police officers for acts of violence.

What do you make of the calls to defend or even abolish the police?

What I find so compelling about abolition, initially in the prison context and extended to the police as well, is that it shifts the conversation and forces us to go through experiments in which we imagine what it would take to build that world. I think that exercise is very important, because it pushes us further than we are naturally inclined to go. Cultivating a broader imagination is an incredibly important part of this work, because as you know from my book, often it was lack of imagination that caused people to fall back on [punitive policies]. 

That's what caused D.C. Councilmember David Clarke to call the police rather than public health experts when he was overwhelmed with letters about heroin addicts in public space. He was anti-drug war, but he couldn't imagine responding to a call for help with heroin addicts with anything other than police. That's a very common move from even really good and progressive people. 

People who are for defunding, for abolition, are absolutely right about reinvesting that money into alternative structures that support communities. But the reinvestment part doesn't follow naturally from the terms. We might want to come up with a term that captures the new stuff we want to do. I think that's particularly important because one of the reasons Black communities have ended up supporting more police is that Black communities have always wanted their fair share of the resources.

Then, the evidence suggests the United States has too many police officers doing prophylactic, preventative, or stop-and-frisk style policing. The style of policing that leads to district level harassment, pulling people over for no reason. But we have too little investment in the parts of police departments that investigate unsolved crimes. I'm talking about the investigator or the detective who comes to your house after there's been a robbery, an assault, a rape, or homicide. 

As compared to European countries, in the United States we actually underinvest in those parts of our police departments. Jill Leovy’s book Ghettoside shows this in dramatic detail. She describes an LAPD that's stopping and frisking Black drivers wantonly and yet the homicide detectives are still relying on a fax machine and the fax machine is broken. They have to go with their own money to Staples to buy a printer. Meanwhile, other aspects of the department are kitted out in this ridiculous riot gear that makes them look like they're in Fallujah. 

That under investment is particularly damaging to Black communities because we're disproportionately victimised by crime. Because of racism and this allocation of resources, the police are less likely to respond in Black communities. The kids I used to work with in the charter schools in DC, we talk about no snitching, but one of the reasons they would never call the police after they'd been victimised by crime is they would say, “They're not even going to come. You're wasting time.” 

I did a Q&A with Jill Leovy too and her argument is one I've struggled to articulate in our present moment. She argues the state doesn't have a monopoly on violence in low-income Black neighbourhoods, because investigations of violence are deemphasised and crime victims or their loved ones often take retribution into their own hands.  But right now, establishing or preserving the state's monopoly on violence isn't an appealing talking point. 

Yes, this is another thing nobody's talking about. Whatever we're going to do instead of the police has to be accountable to the public. The best, most direct way to have accountability is to have the individuals be public employees. As long as we have 300 million guns in this country at least some of those state employees are going to themselves be armed. It's unreasonable to ask them to do the job without it. Not as many need to be armed as are armed now, but some of them need to be. But they can't be hiding behind union contracts or civil service protections which make it impossible to remove even the worst performing, most abusive officers. 

We can not call them police if we want to. That's semantic, but maybe symbolism matters. But those people have to be state employees. They can work with community-based nonprofits, but there are also communities that don't have as robust of a nonprofit network, and they deserve protection too. These [community] groups have to be accountable to the state and, when they don't exist, the state has to be there. 

Progressives get all the points I just made when it's applied to education. The notion that things be public and accountable to the state is understood when it comes to schools. It's exactly why so many people on the left are opposed to charter schools, because they say they don't have public accountability. They want these things to be a state function. But this point about the difficulty in removing this entirely from the hands of the state is, I think, one that liberals and progressives understand from other contexts.

Jake Blumgart is a staff writer at CityMetric.