Are we set to commute even further?

Change in average journey-to-work travel distance by region (km). Data from BITRE

The Age says jobs in Melbourne are losing pace with sprawl – it cites a new study by BITRE which predicts “an increase in the average commuting distance” by 2026 and a rise in journeys to work involving a road distance of more than 30 kilometres.

If a rigorous, hard-nosed body like the Bureau of Transport, Infrastructure and Regional Economics is saying things are going to get worse in the future, it’s worth sitting up and taking notice, right? It’s true BITRE does say that, but it’s also true the media tends to err toward a sensational rather than a sober interpretation of any given facts. In this instance the story is a bit of a beat-up.

For a start, it’s hardly news that commuting distances could “increase” over a period of 15 years given the spectacular growth in population projected for Melbourne. What matters is the size of any increase – if it’s only a 1% increase over the entire period, that’s an infinitesimal 0.06% p.a. However if it’s (say) 15%, i.e. 1% p.a., that’s worth taking note of. However The Age is silent on this score.

BITRE doesn’t say anything about the size of the predicted increase either. There’s a good reason for that. BITRE’s study isn’t an authoritative prediction of future commute distances as implied by The Age’s story. It doesn’t make forecasts based on the latest data, using innovative modelling techniques and complex algorithms as one might expect. In fact the report isn’t even about the future! – it’s actually about historical population, employment and commuting patterns in Melbourne up to 2006.

The Age relies on what is in effect an ill-advised throwaway line by BITRE. The report states (p 333) that if the Victorian Government’s spatial projections of population and employment through to 2026 are realised, the likely commuting implications include….”an increase in journeys to work involving a road distance of more than 30 kilometres and an increase in the average commuting distance”. There’s no analysis or supporting information behind this assertion, so too much shouldn’t be made of it. The prominence given to it by The Age suggests BITRE should’ve thought a bit harder before including it in a report about the past and the present.

However what BITRE actually has analysed in-depth is the historical change in travel distances – and here the picture is if anything somewhat mixed. The report looks first at what’s happened over 2001-06 (see exhibit). That isn’t necessarily a guide to what will happen in 2026, but it shows how current patterns are trending. The picture it reveals isn’t one of rampant increases in commute distances but rather one of relative stability.

BITRE found the average commute in Melbourne increased from 14.7 to 14.8 km, or by just 100 metres over five years. That’s a 0.7% increase, or a miniscule 0.1% p.a. Surprisingly, the average commute increased proportionally less in the outer suburbs than in the inner city – in fact as the exhibit shows, the average commute shortened in absolute terms in the Outer South, Outer East and the Outer West.

This is the real news! It’s important because commute distances have historically increased significantly, while commute times have remained relatively stable. So reliable evidence that commute distances have stabilised, even for five years, is noteworthy.

Some caution is needed though. While not as reliable as Census data, ABS surveys suggest the average commute distance in Melbourne may have increased at a faster rate since 2006. If so it’s not clear why – perhaps it reflects the greater use of trains for the journey to work over the last five years? It’s a pity BITRE chose to undertake this extensive study so close to the release of the 2011 Census results, as the latter would’ve provided more up-to-date information.

Overall though, there’s no objective basis for The Age’s story. I’m even more mystified by the paper’s claim in its opening para that the number of people driving more than 30 kilometres to work in Melbourne will increase in coming years.

I can’t find anything in the BITRE report to support that contention. Apart from having very little to say about the future, the report doesn’t disaggregate the historical data on commuting distance by mode. My best guess is The Age has interpreted BITRE’s use of the term “road distance” to mean driving, whereas BITRE probably (somewhat clumsily) meant non-Euclidean distance.

There’s still the related issue of whether commute distances are simply too long. I’ve looked before at commute times, but not specifically at distance – I’ll do that another time.

7 Comments on “Are we set to commute even further?”

  1. Oz says:

    Commentry without reference to VATS and VISTA 1994 to 2009 for the MSD where evidence exists on commute distances and times is also a shallow analysis

  2. Alan Davies says:

    Re my second last para, burrowing further into BITRE’s report, I see (p233) they use the shortest “road distance” to proxy for “the shortest rail distance, cycling distance, walking distance, etc”. So it definitely doesn’t mean just driving.

    @Oz, the report considers and uses VISTA.

  3. Peter says:

    Some research in the UK a few years ago, written up in NewScientist, made the case that the average commuter tended to take a certain average time to get to work. I think it was about 30+ minutes.
    What the reseacher found was that when given another faster means of travel commuters tended to shift work or home maintaining the same travel time. Its almost as if the time itself was what mattered.
    Another upshot of this is that the roads are clogged because we need or want that travel time.
    I cant seem to find the original article but it has a certain ring of truth about it after reading Ivan Illich saying that each hour of work and other time spent over having a car achieved only 5 miles of driving. This means pretty much that we could have walked everywhere instead.

  4. […] and development issues with a particular focus on Melbourne, Australia Are we set to commute even further? […]

  5. krammer56 says:

    Alan, another slant on this comes from a paper I came across recently (30 years of travel in Melbourne: 1978/79 and 2007/08 by Craig A. McGeoch – that compared the results from the two household travel surveys.
    Interestingly, while it noted a slight increase in car driver travel distance, it also noted only a slight change (mainly decline) in travel time, implying higher average speeds. This suggests that we are actually moving faster around melbourne by car now than in the late 1970’s. I guess this is hardly surprising given the massive road investment since that time, but does somewhat refute the “end of the world” claims about congestion we regularly see reported in the papers.
    Another interesting bit of info was that the average bike trip length had more than doubled.

  6. I agree with Alan davies.

    ” It’s a pity BITRE chose to undertake this extensive study so close to the release of the 2011 Census results, as the latter would’ve provided more up-to-date information.”

    The useless system of urban and transport planning planning in Australia in due the lack of effective coordination between Commonwealth agencies. In China the 2010 Census data is coming out quickly. The Australian Census data is very good bit never comes out early enough so other agencies are trying to jump the gun with reports that in time conflict with ABS. There so many contradictory reports with dodgy forecasts based.

    The greatest priority should be speeding up the release of ABS census and paying it by getting rid of the the interlectual deadwood in the BITRE.

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