Friday, November 21, 2014

Professor Elise Miller-Hooks visit ITS Monash

Professor Elise Miller-Hooks from University of Maryland meet with ITS students and faculty at Monash University.

Wednesday, November 19, 2014

"Peak Car" in Australia

Following a discussion on young people driving trends in Australia posted on the ITS LinkedIn page by Alexa Delbosc, one of my colleagues, here I am posting a few graphs showing an apparent "Peak Car" in Australia.

The total VKT (in million) between 1965 and 2012 in Australia is shown first. What I see in this graph is an increasing trend. However, if you look more closely you may notice that the increase rate is actually going down a little bit (the slope becomes smaller).
The slowing down rate is more obvious when I plot the change in total VKT from year n-1 to year n as shown below. The change in VKT has been fluctuating year to year. However, I see a general decreasing trend there.
And now if we divide the total VKT by total population to get the VKT per capita, we can see a peak in the graph happened in 2004. This is 3-4 years before the Global Financial Crisis (GFC)!
This is actually very interesting because the decline in VKT per capita in the US started in 2006, about 1-2 years before the GFC (reference). It was also in 2006 when the American housing market had a burst with house values peaking (reference).

Did a same thing happen in Australia? Is there really a relationship between housing prices, income, and people's driving trends? I'll get back to this question with some data from Australia in a bit.

Here is the change in VKT per capita from year n-1 to year n. I see a similar decreasing trend with many fluctuations.
Going back to the question on the relationship between housing boom and driving trends, here is also some data from Australia showing a "local" (not global) housing boom in 2003-2004 about the same time as the apparent "Peak Car" happened. The graph below shows the ratio of median residential house price over the annual wage & salary in Australia. Data is from ABS and REIV.

Does this mean people started shifting their behavior towards less consuming (fuel/driving) because they were too in debt on their housing costs? I don't have a certain answer yet. After a local boom in housing prices in 2004, there has been a relatively stable (on average) period until more recently.
The other question which still remains open is "will this trend continue?" To answer this question, we need to understand why we see what we see. If we figure out the driving factors that push VKT up or down, then we may be able to forecast the future. Forecasting is a difficult task.

UPDATE: Following you'll see a few more graphs for fuel price, fuel budget, unemployment rate, and young adult (18-34 years old) proportion.

What is fuel budget?
Fuel budget is defined as the budget that a person spends on fuel in a year.

How did we estimate fuel budget?
Fuel budget = fuel price [$/liter] x average fuel consumption [11.5 liter/100 km] x VKT per capita [km/person/year]

Tuesday, November 18, 2014

The Cost of Traffic Jam

A recent article on The Economist on cost of congestion, based on a report by INRIX:

"The Centre for Economics and Business Research, a London-based consultancy, and INRIX, a traffic-data firm, have estimated the impact of such delays on the British, French, German and American economies. To do so they measured three costs: how sitting in traffic reduces productivity of the labour force; how inflated transport costs push up the prices of goods; and the carbon-equivalent cost of the fumes that exhausts splutter out.
In America the average cost of congestion to a car-owning household is estimated to be $1,700 a year; in France it is $2,500. But traffic is so bad in Los Angeles that each resident loses around $6,000 a year twiddling their thumbs in traffic—at a total cost of $23 billion, the costs are estimated to exceed that of the whole of Britain. But these costs do not take account of the price of carbon-dioxide emissions. In total, over 15,000 kilotons of needless CO₂ fumes were expelled last year—which would cost an additional $350m to offset at current market prices. In choked-up Los Angeles $50m alone would have to be set-aside."