Are Australian cities becoming denser?

Tue 5 November, 2013

Please refer to a fully revised second edition of this post – published in April 2019.

[Updated April 2017 with 2015-16 population estimates. First published November 2013]

While Australian cities have been growing outwards with new suburbia, they have also been getting denser in established areas, and the new areas on the fringe are often more dense than growth areas used to be (see last post). So what’s the net effect – are Australian cities getting more or less dense?

This post also explores measures of population-weighted density for Australian cities large and small over time. It also tries to resolve some of the issues in the calculation methodology by using square kilometre geometry, looks at longer term trends for Australian cities, and then compares multiple density measures for Melbourne over time.

Measuring density

Under the traditional measure of density, you’d simply divide the population of a city by the metropolitan area’s area (in hectares). As the boundary of the metropolitan areas seldom change, the average density would simply increase in line with population with this measure. But that density value would also be way below the density at which the average resident lives because of the inclusion of vast swaths of unpopulated land within “metropolitan areas”, and so be not very meaningful.

Enter population-weighted density (which I’ve looked at previously here and here). Population-weighted density takes a weighted average of the density of all parcels of land that make up a city, with each parcel weighted by its population. One way to think about it is the residential density in which the “average resident” lives.

So the large low-density parcels of rural land outside the urbanised area but inside the “metropolitan area” count very little in the weighted average because of their small population relative to the urbanised areas. This means population-weighted density goes a long way to overcoming having to worry about the boundaries of the “urban area” of a city. Indeed, in a previous post I found that removing low density parcels of land had very little impact on calculations of population-weighted density for Australian cities. However, the size of the parcels of land used in a population-weighted density calculation will have an impact, as we will see shortly.

Calculations of population-weighted density can answer the question about whether the “average density” of a city has been increasing or decreasing. But as we will see below, using geographic regions put together by statisticians based on historical boundaries is not always a fair way to compare different cities.

Population-weighted density of Australian cities over time

Firstly, here is a look at population-weighted density of the five largest Australian cities (as defined by ABS Significant Urban Areas), measured at SA2 level (the smallest geography for which there exists a good consistent set of time-series estimates). SA2s roughly equate to suburbs.

According to this data, most cities bottomed out in density in the mid 1990s. Sydney, Melbourne and Brisbane have shown the fastest rates of densification in the last three years.

What about smaller Australian cities? (120,000+ residents in 2014):

Darwin comes out as the third most dense city in Australia on this measure, with Brisbane rising quickly in recent years into fourth place. Most cities have shown densification in recent times, with the main exception being Townsville. On an SA2 level, population weighted density in Perth hardly rose at all in 2015-16 (a year when 92% of population growth was in the outer suburbs)

However, we need to sanity test these values. Old-school suburban areas of Australian cities typically have a density of around 15 persons per hectare, so the values for Geelong, Newcastle, Darwin, Townsville, and Hobart all seem a bit too low for anyone who has visited them. I’d suggest the results may well be an artefact of the arbitrary geographic boundaries used – and this effect would be greater for smaller cities because they would have more SA2s on the interface between urban and rural areas (indeed all of those cities are less than 210,000 in population).

For reference, here are the June 2014 populations of all the above cities:

Australian cities population 2014

The following map shows Hobart, with meshblock boundaries in black (very small blocks indicate urban areas), SA2s in pink, and the Significant Urban Area (SUA) boundary in green.  You can see that many of the SA2s within the Hobart SUA have pockets of dense urban settlement, together with large areas that are non-urban – ie SA2s on the urban/rural interface. The density of these pockets will be washed out because of the size of the SA2s.

Hobart SUA image

Reducing the impact of arbitrary geographic boundaries

As we saw above, the population-weighted density results for smaller cities were very low, and probably not reflective of the actual typical densities, which might be caused by arbitrary geographic boundaries.

Thankfully ABS have followed Europe and released of a square kilometre grid density for Australia which ensures that geographic zones are all the same size. While it is still somewhat arbitrary where exactly this grid falls on any given city, it is arguably less arbitrary than geographic zones that follow traditional notions of area boundaries.

Using that data, I’ve been able to calculate population weighted density for the larger cities of Australia. The following chart shows those values compared to values calculated on SA2 geography:

pop weighted density 2011 grid and SA2 australian cities

You’ll see that the five smaller cities (Newcastle, Hobart, Geelong, Townsville and Cairns) that had very low results at SA2 level get more realistic values on the kilometre grid.

You’ll notice that most cities (except big Melbourne and Sydney) are in the 15 to 18 persons per hectare range, which is around typical Australian suburban density.

While the Hobart figure is higher using the grid geography, it’s still quite low (indeed the lowest of all the cities). You’ll notice on the map above that urban Hobart hugs the quite wide and windy Derwent River, and as such a larger portion of Hobart’s grid squares are likely to contain both urban and water portions – with the water portions washing out the density (pardon the pun!). While most other cities also have some coastline, much more of Hobart’s urban settlement is near to a coastline.

But stepping back, every city has urban/rural and/or urban/water boundaries and the boundary has to be drawn somewhere. So smaller cities are always going to have a higher proportion of their land parcels being on the interface – and this is even more the case if you are using larger parcel sizes. There is also the issue of what “satellite” urban settlements to include within a city which ultimately becomes arbitrary at some point. Perhaps there is some way of adjusting for this interface effect depending on the size of the city, but I’m not going to attempt to resolve it in this post.

International comparisons of population-weighted density

See another post for some international comparisons using square km grids.

Changes in density of larger Australian cities since 1981

We can also calculate population-weighted density back to 1981 using the larger SA3 geography. An SA3 is roughly similar to a local government area (in Melbourne at least), so getting quite large and including more non-urban land. Also, as Significant Urban Areas are defined only at the SA2 level, I need to resort to Greater Capital City Statistical Areas for the next chart:

This shows that most cities were getting less dense in the 1980s (Melbourne quite dramatically), with the notable exception of Perth. I expect these trends could be related to changes in housing/planning policy over time. This calculation has Adelaide ahead of the other smaller cities – which is different ordering to the SA2 calculations above.

On the SA3 level, Perth declined in population-weighted density in 2015-16.

When measured at SA2 level, the four smaller cities had almost the same density in 2011, but at SA3 level, there is more separating them. My guess is that the arbitrary nature of geographic boundaries is having an impact here. Also, the share of SA3s in a city that are on the urban/rural interface is likely to be higher, which again will have more impact for smaller cities. Indeed the trend for the ACT at SA3 level is very different to Canberra at SA2 level.

Melbourne’s population-weighted density over time

I’ve taken a more detailed look at my home city Melbourne, using all available ABS population figures for the geographic units ranging from mesh blocks to SA3s inside “Greater Melbourne” (as defined in 2011) or inside the Melbourne Significant Urban Area (SUA, where marked), to produce the following chart:

Note: I’ve calculated population-weighted density at the SA2 level for both the Greater Capital City Statistical Area (ie “Greater Melbourne”, which includes Bacchus Marsh, Gisborne and Wallan) and the Melbourne Significant Urban Area (slightly smaller), which yield slightly different values.

All of the time series data suggests 1994 was the turning point in Melbourne where the population-weighted density started increasing (not that 1994 was a particularly momentous year – the population-weighted density increased by a whopping 0.0559 persons per hectare in the year to June 1995 (measured at SA2 level for Greater Melbourne)).

You’ll also note that the density values are very different when measured on different geographic units. That’s because larger units include more of a mix of residential and non-residential land. The highest density values are calculated using mesh blocks (MB), which often separate out even small pockets of non-residential land (eg local parks). Indeed 25% of mesh blocks in Australia had zero population, while only 2% of SA1s had zero population (at the 2011 census). At the other end of the scale, SA3s are roughly the size of local councils and include parklands, employment land, rural land, airports, freeways, etc which dilutes their average density.

In the case of SA2 and SA3 units, the same geographic areas have been used in the data for all years. On the other hand, Census Collector Districts (CD) often changed between each five-yearly census, but I am assuming the guidelines for their creation would not have changed significantly.

Now why is a transport blog so interested in density again? There is a suggested relationship between (potential) public transport efficiency and urban density – ie there will be more potential customers per route kilometre in a denser area. In reality longer distance public transport services are going to be mostly serving the larger urban blob that is a city – and these vehicles need to pass large parklands, industrial areas, water bodies, etc to connect urban origins and destinations. The relevant density measure to consider for such services might best be based on larger geographic areas – eg SA3. Buses are more likely to be serving only urbanised areas, and so are perhaps more dependent on residential density – best calculated on a smaller geographic scale, probably km grid (somewhere between SA1 and SA2).

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3 Comments | Australian Cities, Brisbane, Melbourne, Sydney, Urban density, Urban Planning | Tagged: , | Permalink
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What other modes did train commuters use in their journey to work?

Sun 23 June, 2013

Following on from my last post about public transport multi-modality in the journey to work, this post takes a more detailed look at what modes were used in conjunction with trains in journeys to work.

Trains provide a backbone for public transport systems in Australia’s five largest cities, but only a minority of the population within each city is within walking distance of a train station. So what other modes were used in combination with trains for journeys to work in 2011? (according to the ABS census)

2011 train other modes

This chart shows that ‘walking only’ (ie no modes other than ‘train’ specified) was the most common response for people who used trains in four of the five cities, with Perth the notable exception. Perth’s rail network includes two heavily patronised lines that are largely within freeway corridors, with longer than traditional station spacing and much smaller walking catchments for each station. Perth train commuters were therefore much more likely to involve other modes of transport in their journey to work.

Private (motorised) vehicle transport was more common than other modes of public transport in Brisbane, but the other cities were fairly evenly balanced between private vehicle transport and other public transport modes.

Perth had the highest share of train commuters reporting also using buses (almost a third), suggesting the train feeder bus networks are working quite well.

Sydney had a similar rate of other public transport mode use to other cities, despite limited multi-modal fare integration, although Sydney did have the highest reported rate of ‘walking only’ for train commuters.

Melbourne had the second highest rate of other public transport modes being involved, with roughly equal amounts of bus and tram.

What modes are used to access train stations?

The census doesn’t tell us the order of modes used in the journey to work, but I can get a picture of this from Melbourne’s household travel survey, VISTA:

VISTA JTW pretrain mode

(note that train does not appear as this analysis looks at the mode preceding the first use of train).

Some recently published PTV data on use of train stations also allows analysis of estimated access mode splits for 7am-7pm weekday train station entries based on origin-destination surveys of journeys of any purpose.

The following chart shows access modes to non-CBD stations (i.e. excluding Flinders Street, Southern Cross, Flagstaff, Melbourne Central, and Parliament):

Access modes to Melbourne non CBD train stations

The data sets aren’t in strong agreement about ‘walking only’ and private vehicle use, although they all have different measurement frames.

The disparity may support the suggestion that there is under-reporting of rail-feeder modes other than walking in the census – particularly vehicle driver/passenger (see also an earlier post that found people living beyond reasonable walking distance of train stations reporting train and walking only to get to work). On the other hand, it may also be that train-based journeys to work have lower rates of private vehicle use than for other journey purposes.

All the figures also suggest that trams are much more likely to be used after trains in the journey to work in Melbourne, which makes sense, as there are only a few tram lines in suburban Melbourne that feed the rail network, and trams provide comprehensive street-based transport within the inner city area helping to distribute people who arrive by train.

In fact, here is a chart showing the reported access modes for Melbourne’s CBD train stations, showing a much higher tram share of access modes:

Access modes to Melbourne CBD train stations

The data shows walking as the dominant access mode, but also a quite large number of train-train transfers at CBD stations.

Changes over time

So how have these trends changed over time? (at least, as far as people fill out their census forms)

Unfortunately sufficiently detailed data isn’t available for 2001, but here is a comparison of 2006 and 2011 census journey to work data for the five cities:

2006 and 2011 train other modes

You can see for Perth that the ‘walking only’ share dropped in favour of most other modes (following opening of the Mandurah rail line).

Brisbane also had a notable shift away from ‘walking only’, particularly to the use of other public transport modes, which might reflect continued changes in travel habits following full multi-modal fare integration in 2004-05. However Brisbane retained the rate of use of other public transport modes in journeys involving train of all cities.

Adelaide had a decline in buses being part of train-based journeys to work, but an increase in trams and private vehicle drivers.

Melbourne saw an increase in bus use with train journeys, with a decline in all other modes and ‘walking only’.

Sydney saw small increases in ‘walking only’ and bus use for people making journeys to work involving trains.

In terms of bicycles being part of train-based journeys, Melbourne had the biggest increase (from 1.0% to 1.2% of journeys involving trains), while Adelaide went backwards (1.6% to 1.0%, although I have no idea if this might have been weather related).

You might be wondering about trucks, taxis and motorbikes. Okay, well even if you aren’t, I should point out that I have made some assumptions in aggregating the census data:

  • Anyone reporting truck or motorcycle/scooter has been counted as private vehicle driver (although they may have been passengers on such vehicles, although I’m guessing this is less likely than them being drivers)
  • Anyone reporting taxi I have counted as private vehicle passenger.

For more information on other modes used with trains in Melbourne see pages 26-27 of the PTV Network Development Plan for Metropolitan Rail, and recently published PTV data for use of train stations, including access modes.

1 Comment | Australian Cities, Melbourne, Multi-modal | Tagged: | Permalink
Posted by chrisloader

How multi-modal are public transport journeys to work in Australian cities?

Mon 17 June, 2013

It seems public transport intermodal integration is a frequent topic of conversation in Australia’s larger cities. So how multi-modal is public transport travel in our cities?

In this post I’ll look at journeys to work from the 2011 census for the five larger Australian cities with multi-modal public transport networks. The results might not be quite what you expect.

Before looking at the data, I think it is important to think about the factors that might influence the degree of multi-modal public transport commuter trip-making, particularly with regard to radial trips towards city centres:

  • Commuters from the middle and outer suburbs are more likely to require a rapid transit component to their commute to ensure an attractive travel time.
    • Cities with CBD-orientated busways (primarily Brisbane, Adelaide and to a lesser extent Perth) are perhaps less likely to see multi-modal journeys as buses provide both the local pick up and the rapid transit component of the journey.
    • Cities with more extensive train networks are also perhaps less likely to see multi-modal journeys because a greater share of the population will be within walking distance of a train station and not require a feeder mode (eg bus).
  • In cities where transfers are a fundamental part of the network design, there might be higher transfer rates. For example, very few middle and outer suburban bus routes in the larger cities service the CBD, rather they run to train stations where passengers generally transfer to trains to access inner city areas. This is particularly the case in Melbourne and Perth.
  • The same issue applies for people arriving in city centres. For example, Sydney ferry commuters travelling to areas of the CBD not within easy walking distance of a ferry terminal would need to transfers to buses or trains. Adelaide only has one train station which is on the edge of the CBD, effectively forcing transfers onto buses or the tram for most CBD destinations. Perth has two main CBD train stations, although the core employment areas are within reasonable walking distance of these stations. That said, one might argue that an ideal integrated public transport network would encourage people to use local modes (bus or tram) to travel between destinations and major transport nodes within city centres (in all cities except Sydney, such transfers are almost always free). All cities do offer street-based public transport to help circulate commuters within city centres. I also wonder whether these short trips within city centres might be under-reported in census data (perhaps something to explore another time).

Journeys to work in city centres

So, what percentage of all journeys to work in city centres involve multiple public transport modes? (see note at the end of this post about estimation for 2001 figures)

multimodal PT share to city centres

Note the definitions of city centres aren’t perfectly comparable (see earlier post for maps):

  • Melbourne is primarily the CBD (excluding Southbank and Docklands)
  • Perth includes all of the City of Perth
  • Adelaide includes North Adelaide (entire of City of Adelaide)
  • Brisbane is the “Brisbane City” SA2

The first thing to note is that the share of commuters who use multiple public transport modes is very low (considering public transport mode share to city centres is generally very high).

The following chart shows the proportion of public transport journeys to work in city centres that involved multiple modes of public transport:

proportion of PT trips multimodal to city centres

The vast majority of people who use public transport to access jobs in city centres only use one mode. Given that most city centre workers don’t actually live all that far from the CBD, it’s not too surprising as an overall pattern.

Perth is the stand-out for highest multi-modal public transport travel, and largest increase in this type of journey between 2006 and 2011. A few things might explain this:

  • Perth’s rapid transit network is relatively sparse (five train lines and one busway), meaning fewer people can walk to a rapid transit station.
  • Indeed, most train stations on the northern and southern lines have very limited walking catchments, but relatively strong bus feeder services and excellent interchange layouts that make transferring easy.
  • The increase between 2006 and 2011 is no doubt related to the Mandurah line where many previously bus-only journeys have been replaced by bus-train journeys, but it might also relate to improved feeder bus services on other lines.
  • Perth’s high multi-modal share may also reflect a strong focus on timetable coordination. My understanding is that Transperth don’t try to “optimise” train-bus connection times, they force bus timetables to have ideal bus-train connection times, with high vehicle utilisation a secondary priority.

Melbourne comes in second (if Southbank and Docklands were included, the 2011 figure would be 10.3%). Interestingly, there were more train+bus journeys to the city centre, than train+tram journeys.

Sydney is third, despite having four modes of public transport. This perhaps reflects the lack of a fully integrated fare system (ie multi-modal tickets are usually more expensive that single-mode tickets) and the fact many bus routes run parallel to train lines (and it is usually cheaper to stay on the bus rather than transfer onto the train). It’s not clear to me why Sydney would have had a reduction in multi-modality between 2001 and 2006.

Brisbane had a much lower multi-modal share, probably related to a high bus mode share, the presence of busways providing efficient single-mode (often single-seat) travel for a large number of commuters to the central city, many bus routes running parallel to train lines, and the only relatively recent introduction of full multi-modal fare integration in 2004-05.

Adelaide also rates lowly and has been in decline, perhaps relating to the low-frequency train system (that is now receiving an upgrade including electrification). The extension of the Adelaide tram route from Victoria Square to the Entertainment Centre may have reduced the need for existing tram passengers to transfer, but on the other hand may be helping to circulate people arriving in the city on buses and trains.

Outside city centres

The following chart shows how multi-modality compares for public transport journeys to work in city centres and elsewhere: proportion of PT trips multimodal by work loc

Public transport journeys to work in locations outside city centres were much more likely to involve multiple modes, which makes sense as direct rapid services are probably less likely to be available to reach such workplaces. Keep in mind also that public transport mode share of journeys to workplaces outside the city centre are much lower.

Here are the trends over time for multi-modality of public transport journeys to workplaces outside city centres. It shows increases in Perth and Brisbane, declines in Adelaide and Sydney, and little recent change in Melbourne: proportion of PT trips multimodal outside city centres

Perhaps the increase in Brisbane might be attributed to full multi-modal fare integration introduced in 2004/05, providing free transfers between modes. The increase in Perth is no doubt related to the Mandurah rail line opening.

So is the city centre the main destination for multi-modal public transport journeys to work?

CBD share of multimodal PT JTW

In the larger cities the answer is no. In Adelaide and Perth – where over 60% of PT journeys to work are to the CBD – only around half of the multi-modal PT trips are to the city centre.

While a large proportion of multi-modal public transport journeys to work are not to the city centre, I would expect most would still be radial in nature (as jobs are on average closer to the city centre than homes). This is perhaps something to explore in a future post (my guess would be concentrations of multi-modal public transport travel to workplaces surrounding the city centre).

Finally, I’ve had a look at the home origins for multi-modal public transport journeys to work for Melbourne and Perth in 2011. Click to enlarge maps, and note the colour scale is for mode shares 1 to 10%.

Melb 2011 multi PT

In Melbourne the highest concentrations are north of Footscray, where several frequent tram and bus routes feed Footscray station. There are also concentrations in the middle-eastern and middle-northern suburbs, particularly around SmartBus routes.

Perth 2011 multi

In Perth the highest concentrations are in the northern and southern suburbs, where frequent bus routes connect people’s homes to high-speed train services in peak periods.

My next post will continue the multi-modal theme and look at what modes were used in conjunction with trains in the journey to work.

Footnote regarding 2001 estimates

Available data for 2001 only shows mode share in an aggregated summary, including figures for “train and two other modes” and “bus and two other modes”. Not all of these journeys involved multiple public transport modes, and I don’t know exactly how many did.

To estimate 2001 figures of total multi-modal PT journeys, for each city I have calculated the proportion of 2006 journeys that would come under these headings that actually involved multiple PT modes (as detailed data is available for 2006), and then applied these percentages to the 2001 figures for “train and two other modes” and “bus and two other modes” figures.

The result is that around 20% of the total 2001 multi-modal PT journeys are estimated.

I also checked these percentages in the 2011 data, and they were very similar to 2006. For example, 89% of journeys that could be described as “train and two other modes” in 2006 for Melbourne involved multiple PT modes, and in 2011 that figure was 88%. The similarities were weaker for “bus and two other modes”, but the numbers for this category were very small (less than 65 journeys in all cities except Sydney at 145).

4 Comments | Australian Cities, Mode share, Multi-modal | Tagged: | Permalink
Posted by chrisloader

The journey to work and the city centre (Australian cities 2001-2011)

Sat 16 February, 2013

The city centre is a traditional market for public transport, and certainly where public transport mode shares are the highest. Recent strong growth in city centre employment is likely to be the cause of public transport patronage growth in some cities. So I thought it would be interesting to look at public transport mode shares and mode shifts to workplaces within and outside Australian city centres.

Definition of city centres

First up, its important to understand what data I’m analysing. In 2011 the ABS restructured their geography for census and other data. While this change brings many benefits, it creates some challenges when comparing data from previous years. In the analysis I generally compare Statistical Local Areas (SLAs) with Statistical Area Level 2 (SA2) geography, but sometimes I’m just comparing Local Government Areas (LGAs).

Here are the areas I have used as the “central city” for each of the five large Australian cities:

Sydney

The “Sydney – Haymarket – The Rocks” SA2 which is very similar (but not entirely identical) to the “Sydney (C) – inner” SLA. There are only minor variations on the fringe of this area. On the following maps, the dark green area is included in all years, the red areas are only included in 2011, and the blue areas are only included in 2001 and 2006.

Melbourne

The “Melbourne” SA2 and the “Melbourne (C) – Inner” SLA, the former being larger as it includes a triangle of land between Peel/William Street, Victoria Street and Latrobe Street. City of Melbourne CLUE data from 2010 suggests 7.6% of jobs in the SA2 are in this triangle (and not included in the SLA). A previous post found that 2006 journey to work public transport mode shares in this triangle were around 56-61% whereas most of the CBD was around 60-70%. So this study is likely to understate increases in public transport mode share for central Melbourne.

Melbourne+

As Southbank and Docklands include significant employment density, I have created a second definition of central Melbourne that includes these areas, and labelled it “Melbourne+”. Note this area also gains the triangle north of the CBD for 2011 due to boundary changes. While arguably I should also include East Melbourne, data is not available at that resolution for 2001 and 2006, which would mean I would need to expand to include all of the City of Melbourne which is starting to be a lot more than the central city core.

The following map shows the Melbourne and Melbourne+ areas: the green area is included for all years, the red area is only included in 2011, and the yellow area is Southbank/Docklands, that is included in all years for Melbourne+ only.

Brisbane

The “Brisbane City” SA2, which precisely covers the “City – inner” and “City – remainder” SLAs combined. In 2006, “City – inner” accounted for 62% of the entire SA2 employment population, but the public transport mode share of the overall combined area was only about 1% lower than “City – inner”.

This Brisbane SA2 area is shown in green on the following map (the area in yellow represents Fortitude Valley and South Brisbane, referred to later in this post).

Adelaide

The City of Adelaide LGA (which includes North Adelaide). The new SA2 geography splits central Adelaide and North Adelaide, but historical data is not available at smaller resolution than the entire LGA. This area is shown in green in the following map:

Perth

The City of Perth LGA. While there are smaller SLAs and SA2s, there is weak correspondence between the old and new geographies so I had to use local government boundaries instead. This area is shown in green on the following map:

As these central city areas are not consistently defined, comparisons between cities need to be made with caution. That said, the high employment density core of the city is likely to dominate any geography that includes the CBD. For example, of the 94,764 people who travelled to the City of Adelaide, only 7501 travelled to North Adelaide, with the remainder travelling to central Adelaide. Thus, central Adelaide is likely to dominate the results for the City of Adelaide area.

Mode shares for journeys to work in city centres

Previous posts have looked at public transport mode share overall for cities, and journey to work by work location for some cities (Brisbane 2006 and 2011, Sydney 2006, Melbourne 2006 with more to come). Here’s a look at the mode split for city centre areas (as defined above).

Mode split to city centres v2

Note:

  • as discussed above the central areas for Melbourne and Melbourne+ in 2011 are larger that for in 2001 and 2006
  • Adelaide “2011i” refers to central Adelaide excluding North Adelaide.

The chart shows public and active transport mode share increasing in all cities, with the exception of Sydney where there was an increase in private transport use between 2001 and 2006. Public transport dominates in Sydney, Melbourne and Brisbane, with Perth now roughly evenly split between private and public transport, and private transport still being in the majority in central Adelaide. Active transport (walk/cycle) has posted significant gains in all city centres, with Melbourne having the highest share (9.0% in 2011) followed by Sydney (7.9%) and Brisbane (7.8%), with Perth the lowest (6.4%).

mode shift to PT

The above chart shows central Perth has having the strongest mode shift to public transport (in no small part due to the opening of the Mandurah rail line in late 2007), followed by Brisbane, and (perhaps surprisingly) then Melbourne (although Melbourne’s poorer performance may be related to the change in geographic boundaries as discussed above). Adelaide and Sydney were the laggards of public transport mode shift between 2006 and 2011.

mode shift from Private

Again, Perth is the stand-out in mode shift away from private transport in 2011.

Here is another look on the above mode split data with a little more detail, assigning each journey a “main mode” (precedence given to train, bus, any other public transport, vehicle driver, vehicle passengers, bicycle, in that order).

Mode split to city centres detailed

This chart shows trains accounting for around half of all journeys to work in central Sydney and Melbourne and buses being a significant mode in all cities except Melbourne where trams have a significant share. Notably Melbourne’s tram mode share is smaller than all the other cities’ bus mode shares. I note that Sydney is now moving to light rail to try to alleviate CBD bus congestion. Trains delivered less than 10% of central Adelaide commuters to work.

Vehicle passenger journeys are much more common in Adelaide (8.2%) and least common in Sydney, but are in decline in all cities, suggesting a move away from car pooling.

Central Melbourne is the leader in cycling with 3.3% of journeys primarily by bicycle, with Sydney the lowest bicycle share (1.4%).

Number of car journeys to city centres

The following chart shows the absolute change in the number of people whose primary method of journey to work was vehicle driver.

change in vehicle drivers to city centres

*Caution should be applied for Melbourne, as the 2011 geographic area included additional area that in 2006 (and that areas had a lower public transport mode share in 2006).

The stand-out result is Melbourne+, which indicates a lot more vehicle driver commuter trips generated as Docklands and Southbank employment centres expand. Public transport’s mode share for Southbank and Docklands combined increased from 39.4% in 2006 to 46.8% in 2011, but this was not enough to stop an increase in the overall number of vehicle driver trips. My understanding is that parking costs are generally cheaper in Southbank and Docklands compared to the CBD core.

There was a decline in city centre commuter car parking requirements in Sydney, Brisbane and Perth between 2006 and 2011, while central Adelaide had a substantial increase in vehicle driver commuters (despite some mode shift to public transport), no doubt putting pressure on traffic congestion.

Share of jobs in city centres

Are jobs within metropolitan areas concentrating within city centres? The following chart shows the percentage of metropolitan jobs located within the city centre areas defined above, as well as a wider city centre definition for Brisbane.

city centre share of jobs

Comparing cities is dangerous as there is not a consistent definition of city centre. What the data does show is that central Perth is reducing its share of metropolitan jobs, central Adelaide’s share seems relatively static, central Sydney’s share is growing, and for Melbourne and Brisbane, the central city share is growing but only if you also include nearby employment-focussed areas (Southbank and Docklands for Melbourne, South Brisbane and Fortitude Valley for Brisbane).

In the above analysis I have used my own definitions for metropolitan areas, as ABS have changed from using Statistical Divisions to sometimes larger Greater Capital City Statistical Areas for metropolitan areas. See the appendix at the end of this post for how I have defined metropolitan regions.

Comparing journeys to work inside and outside city centres

Here is a chart comparing 2011 public transport mode shares for journeys to work inside city centres, outside city centres, and for each city overall:

PT mode share in out of city centre

The differences are very stark, but as you might expect as it is generally easier to drive and cheaper to park at workplaces outside the city centre (plus public transport service quality is often lower). Note that many city fringe areas are included in the “outside city centre” figures, and public transport mode shares are generally higher in these areas, and lower further out. You can see the mode share for trips to workplaces outside “Melbourne+” (Melbourne + Southbank + Docklands) is only 9%.

Here’s the trend for public transport mode share to destinations outside city centres, showing increases between 2006 and 2011 for all cities except Adelaide.

PT mode share to outside city centre

The following chart shows that mode shifts to public transport have been much higher in central city areas for Brisbane, Perth and Adelaide, but not Sydney (low mode shift to both city centre and elsewhere) and Melbourne. Mode shift to public transport outside the “Melbourne+” city centre was just over 1%.

mode shift to PT by in out city centre

Growth in public transport for journeys to work versus all purposes

The following chart compares the growth in the absolute number of people choosing public transport to get to work (between census 2006 and 2011), versus overall growth in public transport patronage (comparing financial years 2010-11 to 2005-06).

JTW versus overall PT growth v2

Note: For Brisbane, the overall patronage growth figure refers to all of South East Queensland (SEQ).

In all cities except Melbourne, the number of public transport journeys to work increased faster than overall patronage, suggesting growth in public transport use for other trip purposes was weaker.

Do city centres dominate journeys to work by public transport?

We think of city centres as the main workplace location where people would use public transport to get to work. But is this accurate?

central city share of PT JTW

The answer is yes in the smaller cities, no in Sydney, and in Melbourne it depends on whether you include Southbank and Docklands.

Conclusions

We have seen that:

  • Public transport is the dominant mode of journeys to work in city centres in the larger cities, but a minority mode in central Adelaide
  • Perth has shown the greatest shift to public transport for travel to the central city
  • Melbourne has shown the greatest shift to public transport for journeys to work overall
  • Melbourne has the highest active transport (and bicycle-only) mode share for journeys to city centres
  • In Brisbane, Perth and probably the Melbourne CBD, there was a net decline in private vehicles being driven to city centres for work between 2001 and 2011
  • Public transport’s share of journeys to workplaces outside city centres is much lower in all cities
  • Mode shift to public transport for journeys to work was higher for city centres except Sydney and Melbourne
  • Growth in public transport use for journeys to work was higher than overall public transport patronage growth in all cities except Melbourne
  • The central city share of all metropolitan jobs is increasing in Sydney, Melbourne (when Southbank and Docklands are included), and to a lessor extent Adelaide. Central Perth and Brisbane are declining in their share of metropolitan jobs.
  • Most public transport journeys to work in the smaller cities are to the city centre, but this is not the case for Sydney and Melbourne (without Southbank and Docklands)

Appendix: Common definitions of city metropolitan regions 2001-2011

The change in ABS geography makes it difficult to have a fair time series estimate of the total number of jobs in each metropolitan area. To try for maximum consistency across the change, I have calculated the number of jobs in each city as follows:

Melbourne: Melbourne Statistical Division, plus Shire of Yarra Ranges – Part B (ie includes all of the Shire of Yarra Ranges)

Perth: Perth Statistical Division plus the City of Mandurah (which was incorporated into the Greater Perth definition in 2011)

Brisbane: The Greater Brisbane Capital City Geographic Area, which for 2006 was approximated by the Brisbane Statistical Division plus the SLAs of Beaudesert Part C, Beenleigh, Bethania-Waterford, Boonah, Eagleby, Edens Landing-Holmview, Esk, Kilcoy, Laidley, Mt Warren Park and Wolfdene-Bahrs Scrub.

Sydney: there are very few differences between the Sydney Statistical Division and Greater Sydney, so I assumed equivalence.

Adelaide: All LGAs in the Adelaide Statistical Division, including all parts of the Adelaide Hills Council.

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