Charting Transport

[post updated in April 2011]

Thanks to the Bureau of Infrastructure, Transport and Regional Economics’ Australian Infrastructure Statistics Yearbook 2011, a great set of time series data is available on transport behaviour. This post looks at trends in private and public transport use in Australian cities up until 2008-09, and shows evidence of mode shift from cars to public transport in most cities.

The first chart shows car passenger kms per capita peaked in 2004 for all cities and has been in decline since then. In particular, Melbourne and Brisbane show considerable drops in 2008-09.

Does this mean we are travelling less? The following chart shows estimated motorised passenger kms per capita (ie excluding walking and cycling), and yes in all cities there appears to be a decline in motorised passenger kms after a 2004 peak. This might be people taking shorter trips, people taker fewer trips, and/or people substituting motorised transport with non-motorised transport.

But there is another story in the data. Over the same time, mass transit passenger kms per capita have risen signficantly in many cities:

The data also allows calculation of mass transit’s share of motorised passenger kms:

Note there are other ways to more directly measure transport mode share – primarily household travel surveys, covered in another post.

Before I go further, some disclaimers:

• I’ve called it “mass transit” as the data does not seem to differentiate public, school and private bus passengers. Passengers on chartered buses aren’t usually considered “public transport”.
• km figures are reported on financial years – eg the “2008″ figure above is for financial year 2007-08. Population figures are for June at the end of that financial year. So the “real” per km figures are slightly less, but I’m really just looking at trends and relative numbers.

Commentary:

• Melbourne and Brisbane are the standouts for public transport mode shift based on these figures. Sydney has seen a slower mode shift, while Perth has had a more recent shift following the opening of the Mandurah rail line in December 2007.
• Adelaide and Canberra are the only cities not showing a mode shift to public transport in recent years.
• Canberra has the highest car passenger kms per capita – perhaps due to the low density city and relatively sparse bus services. In the previous 2009 yearbook figures, Melbourne showed up as second highest, but this has changed significantly.
• Sydney shows up with many more mass transit kms per capita than any other city (70% of which is on rail). While I am not sure how BITRE sourced their train patronage data for “Sydney”, my experience is that CityRail patronage data is only available for the entire system, which includes lines beyond the Sydney Statistical Division including Newcastle, Nowra, and the Hunter Valley.
• Strong growth in Brisbane might reflect considerable recent investment in bus services in recent years (BITRE have published three years of bus data that shows Brisbane increasing from 53.0 million kms in 2005-06 to 61.2 million kms in 2007-08).
• Canberra mass transit passenger kms has declined in recent years (bus kms there declined from 17.4m to 16.2m kms between 2005-06 and 2007-08).
• You can see a spike in mass transit use in Sydney in 2000/01 – reflecting the Olympic Games.

How reliable is the data?

• The km figures are all BITRE estimates, from various sources. The private transport figures are revised estimates of the BITRE report Estimating Urban traffic and congestion cost trends for Australian cities (working paper 71) which are based on the ABS Survey of Motor Vehicle Use (SMVU), which is not ideal for historical comparisons (refer note 14). BITRE have smoothed the year to year “noise” in the SMVU, I’m not sure how.
• The Melbourne data can be compared to growth figures reported by VicRoads. The following chart compares the BITRE figures for total Melbourne vehicle kms with the annual Melbourne traffic growth figures reported by VicRoads in their Traffic System Performance Monitoring. It suggests BITRE may have been more optimistic about traffic growth in recent years, which means the mode shift visible above may be understated for Melbourne.

This chart also shows a very interesting recent trend in total vehicle kms in Melbourne (more evidence of mode shift). See another post on Melbourne traffic trends.

Business as usual no longer

In the BITRE’s 2007 report on congestion, they made a “business as usual” assumption that mode shares will not change (ref page 8), and then forecast that avoidable congestion costs in Australia will more than double between 2005 and 2020.

The new BITRE evidence is that mode shares are not business as usual, so old forecasts might need a little revision (I’m not necessarily implying congestion costs won’t rise however).

But having said that, can you accurately forecast future mode shares? Well, if you could accurately forecast future oil prices then that would be a good start! If the peak oil theory is correct (and few people claim global oil production can increase every year indefinitely), the old business as usual mode share assumption looks even more shaky.

This entry was posted on Friday, January 8th, 2010 at 8:55 pm and is filed under Australian Cities, Melbourne, Mode shift, Road Traffic. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.