Update on Australian transport trends (December 2020)

Sun 3 January, 2021

Each year, just before Christmas, the good folks at the Australian Bureau of Infrastructure, Transport, and Regional Economics (BITRE) publish a mountain of data in their Australian Infrastructure Statistics Yearbook. This post aims to turn those numbers (and some other data sources) into useful knowledge – with a focus on vehicle kilometres travelled, passenger kilometres travelled, mode shares, car ownership, driver’s licence ownership, greenhouse gas emissions, and transport costs.

Of course the world of transport changed significantly in 2020, with suppressed movement from around mid March, as the COVID19 pandemic led to movement restrictions across Australia. Most of the following data is for financial years, so you will see some impacts where data is available for financial year 2019-20.

Vehicle kilometres travelled

Total vehicle kilometres travelled has been increasing most years, until 2019-20, when it fell from 264 to 247 billion kilometres.

Here’s the growth by vehicle type since 1971:

Light commercial vehicle kilometres have grown the fastest, curiously followed by buses (although much of that growth was in the 1980s). In 2019-2020, there were noticeable reductions for most vehicle types, except trucks.

Car kilometre growth has slowed significantly since 2004, and actually peaked in 2016-17 according to BITRE estimates.

On a per capita basis car use peaked in 2004, with a general decline since then. Here’s the Australian trend (in grey) as well as city level estimates until 2015 (from BITRE Information Sheet 74):

Technical note: “Australia” lines in these charts represent data points for the entire country (including areas outside capital cities).

Darwin has the lowest average which might reflect the small size of the city. The blip in 1975 is related to a significant population exodus after Cyclone Tracey caused significant destruction in late 1974 (the vehicle km estimate might be on the high side).

Canberra, the most car dependent capital city, has had the highest average car kilometres per person (but it might also reflect kilometres driven by people from across the NSW border in Queanbeyan).

The Australia-wide average is higher than most cities, with areas outside capital cities probably involving longer average car journeys and certainly a higher car mode share. There was a sharp drop in vehicle kms per capita in 2019-20, almost certainly due to COVID-19.

Passenger kilometres travelled

While BITRE’s passenger km estimates were available up to 2019-20 at the time of writing, city population estimates were only available up until June 2019. So in this section, per capita data stops at 2018-19 (before COVID-19), while total km charts go to 2019-20.

Here are passenger kilometres per capita for various modes for Australia as a whole (note the log-scale on the Y axis). Unfortunately BITRE have not published national estimates beyond 2017-18 in their 2020 Yearbook.

Air travel took off (pardon the pun) in the late 1980s (although with a lull in 1990 due to the pilot’s strike), car travel peaked in 2004, bus travel peaked in 1990 and has been relatively flat since, while rail has been increasing in recent years.

Car passengers

Here’s a chart showing total car passenger kms in each city:

The data shows that Melbourne overtook Sydney in 2016-17 as having the most car passenger travel, but then cities were even again in 2019-20 with COVID19 impacts.

Another interesting observation is that total car passenger travel declined in Adelaide in 2018-19 (pre-COVID) according to (revised) BITRE estimates.

However there are large differences in population growth rates between cities. So here is the data per capita:

While car passenger kilometres per capita peaked in 2004 in all cities, there were some increases from around 2013 to 2018 in some cities, but most cities declined in 2019 and 2020 (the latter being no doubt partly related to COVID-19). Darwin is an outlier with an increase in car passenger kms per capita between 2015 and 2020.

Rail passengers

Here are rail passenger kms per capita to 2018-19:

Sydney had the highest train use of all cities and this has been taking off in recent years, likely due to service level upgrades. Other cities have been flat or were in decline (such as Melbourne).

You can see two big jumps in Perth following the opening of the Joondalup line in 1992 and the Mandurah line in 2007. Melbourne, Brisbane and Perth have shown declines over recent years.

Here is growth in total rail passenger kms since 2010 (NOT per capita):

Sydney trains saw rapid growth in the years up until 2019, again probably reflecting significant service level upgrades to provide more stations with “turn up and go” frequencies at more times of the week.

Adelaide’s rail patronage dipped in 2012, but then rebounded following completion of the first round of electrification in 2014.

All cities saw significant declines in 2019-20 with COVID-19 impacts, although BITRE caveats that the 2019-20 estimates for public transport modes were “rough” at the time of publication.

Bus passengers

Here’s bus passenger kms per capita up to 2018/19:

Bus passenger kms per capita have been declining in most cities in recent years, with the exception of Sydney.

Significant investments in bus services in Melbourne and Brisbane between around 2005 and 2012 led to significant patronage growth.

Melbourne has the lowest bus use of all the cities, but this likely reflects the extensive train and tram networks carrying the bulk of the public transport passenger task. Melbourne is different to every other Australian city in that trams provide most of the on-road public transport access to the CBD (with buses performing most of this function in other cities).

Darwin saw a massive increase in bus use in 2014 thanks to a new nearby LNG project running staff services.

Australia-wide bus usage is surprisingly high. While public transport bus service levels and patronage would certainly be on average low outside capital cities, buses do play a large role in carrying children to school – particularly over longer distances in rural areas. The peak for bus usage in 1990 may be related to deregulation of domestic aviation, which reduced air fares by around 20%.

Here is growth relative to 2010:

All cities saw a substantial reduction in 2019-20 due to COVID-19, with Hobart having the smallest reduction. Perhaps there is less discretionary and office-commuter travel on Hobart’s buses?

Light rail passengers

Light rail passenger kms per capita is not really meaningful as Melbourne has a large network, while Sydney and Adelaide have very small (although growing) networks. Here is estimated passenger km growth since 2010:

Sydney light rail patronage increased following the Dulwich Hill extension that opened in 2014, and again with the new lines joining the CBD with Randwick and Kingsford opening in 2019-20. The passenger km growth would have been higher if not for COVID-19.

Adelaide patronage increased following an extension to the Adelaide Entertainment Centre in 2010, and then flatlined for several years. In October 2018, new extensions to Festival Plaza and Botanic Gardens opened but passenger kms actually declined in FY 2018-19.

Mass transport

We can sum all of the mass transport modes (I use the term “mass transport” as the numbers include both public and private bus services). Firstly. here is mass transit share of estimated total motorised passenger kilometres in each city (unfortunately there are no estimates of walking and cycling kilometres):

All cities saw a mode shift away from mass transit in 2019-20 due to COVID-19, which likely reflects the shift to working from home for CBD workers (with such commuter trips making up a substantial share of PT patronage). During the recovery after lockdowns, road traffic has returned to almost normal in most cities, whilst public transport patronage is still well down on pre-COVID19 levels. I should mention again that BITRE describe their 2019-20 estimates of non-private passenger kilometres as “rough”.

But looking at trends prior to 2019-20, Sydney was leading the country in mass transport use per capita which was also rising fast to 2019, with a 2% mode shift between 2016 and 2019 (mostly attributable to trains). The Sydney north west Metro line opened in May 2019, so would only have a small impact on these figures.

Melbourne mass transit had been losing mode share between 2012 and 2019, while other cities have been largely flat or trending down (although Brisbane, Adelaide, and Perth has a small increase in 2018-19).

Melbourne made significant gains between 2005 and 2009, and Perth grew strongly 2007 to 2013, but has since shifted away from public transport (which may be related to a decentralisation of employment).

Here is growth in mass transport passenger kms since 2010:

Darwin saw substantial growth associated with staff bus services to a new LNG plant, while Sydney otherwise was leading in mass transit passenger kilometre growth.

Here’s how car and mass transit passenger kilometres have grown since car used peaked in 2004:

Mass transit use has grown much faster than car use in Australia’s three largest cities. In Sydney and Melbourne it has exceeded population growth, while in Brisbane it is more recently tracking with population growth.

Mass transit has also outpaced car growth in Perth, Adelaide, and Hobart:

In Canberra, both car and mass transit use has grown much slower than population, and it is the only city where car growth has exceeded public transport growth.

Motorcycles

Here are motorcycle passenger kms per capita:

Motorcycle travel was declining per capita until 2000, had a resurgence between 2004 and 2009 (perhaps as fuel prices rose?) and has since reduced somewhat in most cities. I’m not quite sure what might have happened in Melbourne in 2006 to suddenly stop the growth in use. I also wonder about the precision of estimates of motorcycle passenger kilometres, given it is such a small mode.

Car ownership

The ABS conduct a Motor Vehicle Census generally once per year (although less often historically), and the following chart includes that data up until January 2020, combined with population estimates released in December 2020.

Car ownership has risen significantly over time, although this growth has slowed considerably more recently in some states.

However the above measure doesn’t take into account people not of driving age. So the following chart looks at passenger cars per persons aged 18-84 (for want of a better definition of driving aged persons):

It’s still a bit hard to see the more recent trends, so here is a chart that looks at 2000-2020, excludes the Northern Territory (zooming on the top-right section):

This data shows that car ownership peaked in Victoria in 2013, Western Australia in 2017, New South Wales in 2017, Queensland in 2018, South Australian in 2018, and Australia overall in 2018. The Australian Capital Territory may have peaked in 2019 but perhaps it is a little too early to call, while Tasmanian now has the highest car ownership in the country and is still growing strongly.

My previous analysis of census data found that Melbourne was the only large city to see a decline in car ownership between 2011 and 2016 (see also an older post on car ownership).

Motorcycle ownership

Here is a chart showing motorcycles per persons aged 18-84:

This chart shows a slightly different pattern to that of motorcycle passenger kilometres per capita in cities (above). Ownership and usage bottomed out around the 1990s or 2000s (depending on the state/city). However ownership has risen in most states since then, but usage apparently peaked around 2009 in most cities. This perhaps suggests motorcycles are now more a recreational – rather than everyday – vehicle (I really don’t follow the motorcycle industry very closely so others might better explain this).

Driver’s licence ownership

Thanks to BITRE Information Sheet 84, the BITRE Yearbook 2020, and some useful state government websites (NSW, SA, Qld), here is motor vehicle licence ownership per 100 persons (of any age) from June 1971 to June 2019 or 2020 (depending on data availability):

Technical note: the ownership rate is calculated as the sum of car, motorbike and truck licenses – including learner and probationary licences, divided by population. Some people have more than one driver’s licence so it’s likely to be an over-estimate of the proportion of the population with any licence.

There’s been slowing growth over time, but Victoria has actually seen slow decline since 2011, and the ACT peaked in 2014.

Here’s a breakdown by age bands for Australia as a whole:

Licencing rates have been increasing over time for those aged over 40 (most strongly for those aged over 70), and have been declining for those aged under 40, although there was a notable uptick in licence ownership for 16-19 year-olds in 2018.

The next chart shows licencing rates for teenagers:

Licence ownership rates for teenagers had been trending down in South Australia and Victoria until 2017, while most other states have been trending upwards in recent years. The differences between states partly reflects different minimum ages for licensing.

Here are 20-24 year olds:

The largest states of Victoria and New South Wales had seen downwards trends until 2019, while all other states and territories are trending up. The big upticks in 2020 for Queensland and NSW might be a new trend, might also be impacted by the preliminary nature of June 2020 population estimates from the ABS, and/or might be impacted be an exodus of international students.

25-29 year olds are a mixed bag – Victoria has been trending downwards sharply, New South Wales has (probably) just ended a downwards trend, while most other states have been increasing or relatively steady.

Licencing rates for people in their 70s have been rising in all states, although it may be slowing in Western Australia and NSW more recently (I have excluded 2016 for South Australia as I suspect a data error):

A similar trend is clear for people aged 80+ (Victoria was an anomaly before 2015):

See also an older post on driver’s licence ownership for more detailed analysis.

For completeness, here is a chart showing motorcycle full licence ownership rates:

Queensland has two types of motorcycle licence and I suspect many people hold both, which might explain a licence ownership rate being so much higher than other states.

Transport greenhouse gas emissions

According to the latest adjusted quarterly figures, Australia’s domestic non-electric transport emissions peaked in 2018, had been slightly declining (which reflects reduced consumption of petrol and diesel) before COVID impacted the year-ending June 2020 figure.

The seasonally-adjusted estimate for the June quarter of 2020 is 19.2 Mt, which is down 24% on the June quarter of 2019:

Non-electric transport emissions made up 19.1% of Australia’s total emissions as at December 2019 (before the COVID-19 impact).

Here’s a breakdown of transport emissions by financial year:

A more detailed breakdown of road transport emissions is available, but only back to 1990:

Here’s growth in transport sector emissions since 1975:

The 2019-2020 estimates are heavily impacted by COVID-19, most evidently in aviation, but also for road transport.

Road emissions had grown steadily to 2019, while aviation emissions took off around 1991 (pardon the pun). You can see that 1990 was a lull in aviation emissions, probably due to the pilots strike around that time.

In more recent years non-electric rail emissions have grown strongly. This will include a mix of freight transport and diesel passenger rail services – the most significant of which will be V/Line in Victoria, which have grown strongly in recent years (140% scheduled service kms growth between 2005 and 2019). Adelaide’s metropolitan passenger train network has historically run on diesel, but has more recently been transitioning to electric.

Here is the growth in each sector since 1990 (including a breakdown of road emissions):

Within road transport, COVID-19 has had the biggest impact on cars, buses, motor cycles and light commercials. However, emissions from (larger) articulated trucks continued to grow.

Here are average emissions per capita for various transport modes in Australia, noting that I have used a log-scale on the Y-axis:

Per capita emissions have been decreasing for cars, and – until 2019 – were relatively stable for most other modes. Total road transport emissions per capita peaked in 2004 (along with vehicle kms per capita, as above).

Transport greenhouse gas emissions intensity

It’s possible to combine data sets to estimate average emissions per vehicle kilometre for different vehicle types, but only until 2018 with published data (note I have again used a log-scale on the Y-axis):

Note: I suspect the kinks for buses and trucks in 2015 are issues to do with estimation assumptions made by BITRE, rather than actual changes.

Most modes have shown slight declines in emissions per vehicle km, except trucks. On these estimates, car have dropped from 281 g/km in 1990 to 243 g/km in 2018.

However, the above figures don’t take into account the average passenger occupancy of vehicles. To get around that we can calculate average emissions per passenger kilometre for the passenger-orientated modes (data only available until 2018 unfortunately):

Domestic aviation estimates go back to 1975, and you can see a dramatic decline between then and around 2004 – followed little change (even a rise in recent years). However I should mention that some of the domestic aviation emissions will be freight related, so the per passenger estimates might be a little high.

Car emissions per passenger km in 2017-18 were 154.5g/pkm, while bus was 79.0g/pkm and aviation 127.2g/pkm.

Of course the emissions per passenger kilometres of a bus or plane will depend on occupancy – a full aeroplane or bus will have likely have significantly lower emissions per passenger km. Indeed, the BITRE figures imply an average bus occupancy of around 9 people (typical bus capacity is around 70) – so a well loaded bus should have much lower emissions per passenger km. The operating environment (city v country) might also impact car and bus emissions. On the aviation side, BITRE report a domestic aviation average load factor of 79.3% in 2019-20.

Cost of transport

The final topic for this post is the real cost of transport. Here are headline real costs (relative to CPI) for Australia:

Technical note: Private motoring is a combination of factors, including motor vehicle retail prices and automotive fuel. Urban transport fares include public transport as well as taxi/ride-share.

The cost of private motoring has tracked relatively close to CPI, although it seems to be trending down since 2008, probably largely related to reductions in the price of automotive fuel (which peaked in 2008). The real cost of motor vehicles has plummeted since 1996, although that trend may have stopped in 2018. Urban transport fares have been increasing faster than CPI since the late 1970s, although they have grown slower than CPI (on aggregate) since 2013.

Here’s a breakdown of the real cost of private motoring and urban transport fares by city (note different Y-axis scales):

Note: I suspect there is some issue with the urban transport fares figure for Canberra in June 2019. The index values for March, June, and September 2019 were 116.3, 102.0, and 118.4 respectively.

Urban transport fares have grown the most in Brisbane, Perth and Canberra – relative to 1973.

However if you choose a different base year you get a different chart:

What’s most relevant is the relative change between years – eg. you can see Brisbane’s experiment with high urban transport fare growth between 2009 and 2017 in both charts.

I hope you have found this interesting.


What impact has the 2020 COVID-19 pandemic had on road traffic volumes in Victoria?

Sun 3 May, 2020

[Last updated 25 July 2020, not all charts]

For the most recently analysis of road traffic volumes – see my twitter feed.

Roads in Victoria were noticeably quieter during the depth of the pandemic shutdown, but just how much did traffic reduced? Has it varied by day of the week, time of day, and/or distance from the city centre? How have volumes increased as restrictions have been eased? What has been the impact naming identifying hot spots and postcode lock downs?

To answer these questions I’ve downloaded traffic signal loop vehicle count data from data.vic.gov.au. The data includes vehicle detection loops at 3,760 signalised intersections across Victoria (87% of which are in Greater Melbourne).

I should state that it is not a perfect measure of traffic volume:

  • It may under-count motorway-based and rural travel which may cross fewer loop detectors.
  • There are occasional faults with loops, and I’m only able to filter out some of the faulty data (supplied with negative count values), so there is a little noise but I will attempt to wash that out by using median counts rather than sums or averages (although charts of averages show very similar patterns to charts of medians).
  • Some vehicles moving through an intersection might get counted at multiple loops, but I would hope this has minimal impact on overall traffic volume trends.

How have traffic volumes reduced during the pandemic?

Firstly, median 24-hour loop volumes for each day:

Note: the actual numbers aren’t very meaningful, it is the relative numbers that matter.

There are regular variances by day type (eg Fridays generally having the most traffic), so here is a chart looking changes by day of the week, relative to the first two weeks of March 2020. I’ve annotated various significant announcements and changes in rules.

At their lowest, weekday volumes went down around 40%, while weekend volumes went down more like 50%.

In late-June volumes were down only 10-20%, with significant growth on Saturdays. However volumes declined again as a second wave of infections hit, and more restrictions were reintroduced. The key turning point was Saturday 20 June when the first warnings were raised about outbreaks, increasing cases, and a slow down in easing of restrictions.

In the early part of the second lock down, volumes were similar to April, the bottom of the first lock down, but then they settled at higher levels (more on that shortly).

Some curious outliers:

  • Thursday 9 April – the day before Good Friday: there may have been some travel to holiday homes, and/or other travel that happens normally on the last workday of the week.
  • Wednesday 8 July – the day before Melbourne and Mitchell Shire re-entered stage 3 restrictions (lock down), suggesting many people brought forward travel activity that was about to no longer be allowed.
  • Saturday 16 May & Sunday 17 May: there was a surge in traffic volumes on the first weekend after restrictions where eased.

Have traffic trends been different in different parts of the state?

There have been many more COVID-19 cases in Melbourne than regional Victoria. Here’s a chart showing daily volume changes in Greater Melbourne:

There is very little difference compared to the whole of Victoria chart, as most signals are located within Greater Melbourne.

Here is a chart of only signals outside Greater Melbourne, showing much less decline in late June / early July.

A notable exception here is Sundays where there has been a decline in July – perhaps Sundays normally involve a lot of travel to/from Melbourne.

How has traffic changed during the second wave?

From late June, there were increasing warnings about outbreaks in LGAs, suburbs, specific postcodes entered lock down before all of Melbourne plus the Shire of Mitchell also went into lock down. This section looks at the impact of some of the responses to what has become a second wave.

On 25 June, 10 suburbs were announced as outbreak concerns, with door-to-door testing campaigns to be conducted. These suburbs were within 6 LGAs identified on 20 June, so this may have refined people’s concern.

It is possible to filter to signal sites in the listed hot spot suburbs, although there are only around 100 signalised such sites (and none at all fall into the small suburb of Albanvale) which makes for some noisy data. Also, I would dare say that a lot of traffic in these suburbs is through traffic rather than local traffic.

To overcome daily noise, I’ve calculated the rolling 7 day average volume – excluding public holidays with with some normalisation (see below chart explanation). That does mean that sudden daily changes in traffic are smoothed out over the following 7 days.

Boring but necessary technical notes: Many traffic signals are on roads that are LGA boundaries – and which LGA an intersection falls into is almost random – it depends on the coordinates of the intersection point. To normalise volumes, I have calculated the ratio of the average volume for each day of the week in February to the overall February average, and then adjusted daily volumes using these ratios to produce a relatively smooth daily time series. The rolling 7 day average then omits any public holidays. It’s not perfect, as you can see around Easter, but it was necessary to avoid having large gaps or blips in the above chart. For this analysis I used February as the baseline, as there was a public holiday in the first two weeks of March, complicating the normalisation.

Volumes immediately dropped more quickly in these suburbs compared to the rest of Melbourne, although they later settled at higher levels than the rest of Melbourne.

On 30 June there was an announcement that 10 postcodes would return to “lock down” (only four essential travel purposes allowed) from 2 July. Those postcodes mostly – but not entirely – lined up with the 10 warning suburbs. Here’s a similar chart that separates out those postcodes, from the rest of Melbourne (plus Mitchell Shire) that went into lock down on 9 July:

There was a step change from 2 July as the restrictions took hold (on top of a reduction from the school holidays), and the rest of Melbourne followed after 9 July.

During the first lock down, these 10 postcodes saw a slightly smaller traffic reduction compared to the rest of Melbourne, but in the second lock down other parts of Melbourne have not seen the same traffic reductions.

The 7 day averaging process hides a little of the behaviour change, so here is a daily volume chart for those 10 postcodes:

While volumes in these postcodes started declining from the first warning announcement on 20 June, if you look carefully you’ll see that on Wednesday 1 July there was little change in volume compared to the previous Wednesday. This was the last day before the lock down, and presumably some people made some extra travel that was about to become against the rules. Once the lock down had commenced, volumes were very similar to those experienced during the “stage 3” restrictions of early April. This is similar to the surge in traffic seen in Melbourne the day before the second lock down.

A more detailed look at Melbourne

The following animated map shows the change in weekday volume relative to the first two weeks of March, for each site, each week since the beginning of March. Note that there are anomalous sites for various reasons (eg faults, roadworks) – I’ve tried to filter out some sites with unusual data, but it’s difficult to get all of them.

If you ignore individual sites that look like outliers you can see some clear patterns:

  • Volumes haven’t reduced as much in industrial areas during lock downs, as freight and logistics largely keep operating, and factory workers continued to go to work.
  • Volumes didn’t recover in the central city as they have in the suburbs, which makes sense with so many office workers have continued to work from home.
  • Melbourne Airport volumes have been significantly below normal throughout, obviously due to national and international travel restrictions.
  • Volumes were slower to recover in the Clayton area – probably related to working from home, and Monash University not having on-campus teaching.
  • Volumes reduced from the week of 29 June, a mix of the school holiday impact, an increase in travel restrictions, and probably general fear about a second wave of infections.

I must apologise to the those with colour-blindness, it’s much more difficult to show the changes with only two-three colours.

This map doesn’t however explain the slightly smaller traffic reduction in Melbourne outside the initial 10 lock down postcodes.

The following map compares traffic volumes on Wednesday 22 July with those in the first two weeks of April (I’ve chosen a Wednesday to be clear of the Easter long weekend that happened in the second week of April). Note that the flip between orange and blue occurs at 110% (you might intuitively expect it to be at 100%).

This map pretty clearly shows that second lock down volumes were higher in the eastern and south-western suburbs, but much closer to April in the north-eastern suburbs. There have been fewer COVID-19 cases in the south-eastern suburbs, and this might reflect people’s self-regulation based on perceived local risk.

Indeed, here is a chart comparing active cases as at 19 July to traffic on 20 July relative to the first lock down:

Local government areas (LGAs) with higher numbers of active cases tend to have traffic levels closer to those in early April, while LGAs with fewer cases have seen higher traffic volumes in April. I might try to explore this relationship over time in future.

How does 2020 compare to 2019?

The above analysis hasn’t differentiated school days and school holidays, and any general seasonality across the year. Here is a chart comparing 2020 with 2019 for weekdays, Saturdays and Sundays (excluding public holidays):

I will emphasise that there will be week-to-week variations, particularly on weekends, due to short term factors such as weather and special events. Also, while school returned in week 16 of 2020, most students were not attending schools in person (ditto week 29).

The winter school holidays began in week 27, and traffic volumes in 2020 appeared to drop in proportion to the traffic reduction in the same week in 2019.

The following chart compares 2020 to 2019 on a daily basis (with 2019 days offset by -1 to align days of the week):

We can also look at the percentage difference between the years, but only for days that have the same day type in terms of school term or holidays, and public holidays where they fall on the equivalent day of the year. So there are some gaps in the following chart, plus some noise due to daily fluctuations:

This chart shows January to late July. There are gaps around the autumn school holidays and Easter as they didn’t perfect match days of the year perfectly.

You need to not get too excited about daily variations (the Tuesday in the second week of 2019 school holidays had unusually low volume in Melbourne for some reason, which shows up as a spike for 2020).

This chart gives a feel for variations from expected patterns. Traffic in the Melbourne was down a similar percentage in the first week of the winter school holidays compared to the previous week of school.

Melbourne traffic volumes began falling in the second week of winter school holidays with the rise in cases and commencement of some postcode lock downs, and then fell further with the Melbourne + Mitchell lock down from 9 July.

However in regional Victoria volumes were relatively higher in the winter school holidays – perhaps as Melbourne people were more likely to travel intrastate for holidays (interstate travel being heavily restricted, and travel not having been an option in the previous autumn school holidays). Regional Victoria travel volumes have been tracking around 10% below 2019 since early June.

The next chart compares each 2020 week with the same week 2019 for Melbourne LGAs plus Mitchell. However it is important to note that there was quite a bit of week to week variation in 2019, and the autumn school holidays started a couple of weeks earlier in 2020.

On this measure, weekdays bottomed out around 38% below 2019, but recovered to be ~10% down in week 24 (on weekdays and Saturdays). Weekends were down around 50%, but recovered to around 10-15% down before the second wave. However pre-pandemic volumes were around 5% higher than 2019, so you could perhaps add another 5% to the reduction figures.

How has traffic reduced by time of day?

The traffic signal data is available in 15 minute intervals, so it is possible to examine patterns in more detail.

Here’s a look at the traffic volumes by time of day for Wednesdays:

You can see a significant flattening of the traditional peaks from late March, although curiously the PM peak still commences around 3 pm, even during the school holidays. From late May there was a significant jump in peak period traffic, coinciding with the return to school of grades Prep, 1, 2, 11 and 12.

1 July was the first week of the winter school holidays and you can see substantial traffic reductions at school times, most notably in the AM peak. Meanwhile the PM commuter peak (around 5 pm) was very similar to late June.

There was a spike in traffic on 8 July – the last day before the second Melbourne full lock down.

Evening traffic was down considerably but it’s a little hard to gauge this reduction the chart. So here is a chart showing traffic volume changes relative to the first two weeks of March (with apologies to anyone with colour-blindness):

Volumes went down the most in the evenings (particularly around 9 pm) which might reflect the closure of hospitality venues, cessation of sports and reduced social activity. The AM and PM peak periods were down around 50% at the bottom, while the inter-peak period has held up the most – being only down around 30%.

Volumes recovered considerably over May and June, with volumes around 3pm back near pre-COVID levels (prior to the winter school holidays). The AM peak is interesting – at 7am, traffic on 17 June was still down around 28%, but at 8:45am is was only around 9% down – possibly reflecting the school peak, and/or a narrowing of the commuter peak (as lower congestion provides less incentive for peak spreading). As at mid-June, evening traffic was still down around 40%.

Again 8 July is an outlier – evening traffic was a lot busier, in fact traffic leading up to midnight was busier than early March, suggesting people cramming in travel activity that was about to become restricted.

I should point out that this analysis compares to a baseline of a two days in early March, and there may be some associated noise (eg weather or event impacts on particular days).

Here is the same for Fridays (excluding the Good Friday public holiday):

Late evening traffic was down even more than for Wednesdays, which probably reflects higher volumes of hospitality-related travel on Friday nights. Friday evening traffic jumped on 15 May when small social gatherings were allowed, and again on 5 June when restaurants and cafes were allowed to have dine-in patrons.

Here is Saturdays (excluding Anzac Day):

The Saturday profile shape hasn’t changed as much as weekdays, but the evenings were down most significantly.

Curiously there are several spikes in the curve in the morning – and they are the 15 minute intervals leading up to the hours of 7am, 8am, 9am, and 10am. Initially I wondered if it was a data quality issue, but I suspect it reflects a surge in travel just before work shifts and other activities that start on the hour.

For some reason traffic volumes were relatively low around 6 am on Saturday 7 March, which has resulted in other days showing less reduction.

Saturday night travel was down considerably – by over 70% by midnight at the depths of the shutdown, but jumped with restrictions easing, similar to Friday evenings. As of mid-June it was down around 25-30%.

You can also see early Saturday morning (Friday night) travel down around 60-70% at worst (discounting 11 April which was the Saturday morning following Good Friday).

Here is Sundays:

Sunday 8 March was on the Labour Day long weekend (including the Moomba festival), which probably explains the much busier traffic that Sunday night (not being a “school night”). You can more clearly see that on the following chart:

Another anomaly here is Sunday 7 June – which was another public holiday eve.

Here’s the profile by day of the week for each week since February (public holidays excluded):

This data suggests a roughly a one hour lag on Sunday mornings compared to Saturday mornings – ie travel volumes hold up an hour later on Saturday nights and ramp up an hour later on Sunday mornings. This pattern holds up for other weeks. It also shows the middle of the day on Saturdays to mostly be busier than the same time on weekdays.

Here’s another look at relative time of day traffic volumes for March through to July:

If you look closely (no, your eyes are not losing focus!) you can see:

  • Significant volume reductions after schools finished on 23 March
  • A surge in traffic on 9 April – the Thursday before Good Friday
  • Extremely quiet traffic on Good Friday (10 April)
  • Higher traffic volumes on 8 July (the day before the second lock down), particularly into the evening.
  • Generally higher traffic on the last weekday of the week, particularly in the afternoon and evening (including during the shut down period)

Have traffic impacts been different by distance from the CBD?

Here’s a chart showing year-on-year reduction in median traffic volumes at intersections by distance from the Melbourne CBD for weeks 14 and 15 (the lowest two weeks of the lock-down):

What is clear is that the central city experienced much larger traffic volume reductions than other parts of Melbourne, which makes sense as office workers stayed home, universities, cafes, restaurants and night-life closed, and (non-essential) retail activity slowed considerably.

There is some noise in the variations by distance from the CBD but I suggest not too much should be read into that as there will be various local factors at play.

The following animated chart shows median weekday volumes per week, by distance from the CBD, since the start of March 2020:

You can see the traffic decline has remained the largest in the central city. The reduction in traffic in the week of 28 June was mostly in the suburbs more than 3 km from the CBD.

Traffic signal data comes out daily, and so I will try to update this analysis at least once a week during the recovery period. There may be more frequent updates on Twitter.


Update on Australian transport trends (December 2019)

Mon 30 December, 2019

Each year, just in time for Christmas, the good folks at the Australian Bureau of Infrastructure, Transport, and Regional Economics (BITRE) publish a mountain of data in their Yearbook. This post aims to turn those numbers (and some other data sources) into useful knowledge – with a focus on vehicle kilometres travelled, passenger kilometres travelled, mode shares, car ownership, driver’s licence ownership, greenhouse gas emissions, and transport costs.

There are some interesting new patterns emerging – read on.

Vehicle kilometres travelled

According to the latest data, road transport volumes actually fell in 2018-19:

Here’s the growth by vehicle type since 1971:

Light commercial vehicle kilometres have grown the fastest, curiously followed by buses (although much of that growth was in the 1980s).

Car kilometre growth has slowed significantly since 2004, and actually went down in 2018-19 according to BITRE estimates (enough to result in a reduction in total vehicle kilometres travelled).

On a per capita basis car use peaked in 2004, with a general decline since then. Here’s the Australian trend (in grey) as well as city level estimates to 2015 (from BITRE Information Sheet 74):

Technical note: “Australia” lines in these charts represent data points for the entire country (including areas outside capital cities).

Darwin has the lowest average which might reflect the small size of the city. The blip in 1975 is related to a significant population exodus after Cyclone Tracey caused significant destruction in late 1974 (the vehicle km estimate might be on the high side).

Canberra, the most car dependent capital city, has had the highest average car kilometres per person (but it might also reflect kilometres driven by people from across the NSW border in Queanbeyan).

The Australia-wide average is higher than most cities, with areas outside capital cities probably involving longer average car journeys and certainly a higher car mode share.

Passenger kilometres travelled

Overall, here are passenger kms per capital for various modes for Australia as a whole (note the log-scale on the Y axis):

Air travel took off (pardon the pun) in the late 1980s (with a lull in 1990), car travel peaked in 2004, bus travel peaked in 1990 and has been relatively flat since, while rail has been increasing in recent years.

It’s possible to look at car passenger kilometres per capita, which takes into account car occupancy – and also includes more recent estimates up until 2018/19.

Here’s a chart showing total car passenger kms in each city:

The data shows that Melbourne has now overtaken Sydney as having the most car travel in total.

Another interesting observation is that total car travel declined in Perth, Adelaide, and Sydney in 2018-19. The Sydney result may reflect a mode shift to public transport (more on that shortly), while Perth might be impacted by economic downturn.

While car passenger kilometres per capita peaked in 2004, there were some increases until 2018 in some cities, but most cities declined in 2019. Darwin is looking like an outlier with an increase between 2015 and 2018.

BITRE also produce estimates of passenger kilometres for other modes (data available up to 2017-18 at the time of writing).

Back to cities, here is growth in rail passenger kms since 2010:

Sydney trains have seen rapid growth in the last few years, probably reflecting significant service level upgrades to provide more stations with “turn up and go” frequencies at more times of the week.

Adelaide’s rail patronage dipped in 2012, but then rebounded following completion of the first round of electrification in 2014.

Here’s a longer-term series looking at per-capita train use:

Sydney has the highest train use of all cities. You can see two big jumps in Perth following the opening of the Joondalup line in 1992 and the Mandurah line in 2007. Melbourne, Brisbane and Perth have shown declines over recent years.

Here is recent growth in (public and private) bus use:

Darwin saw a massive increase in bus use in 2014 thanks to a new nearby LNG project running staff services.

In more recent years Sydney, Canberra, and Hobart are showing rapid growth in bus patronage.

Here’s bus passenger kms per capita:

Investments in increased bus services in Melbourne and Brisbane between around 2005 and 2012 led to significant patronage growth.

Bus passenger kms per capita have been declining in most cities in recent years.

Australia-wide bus usage is surprisingly high. While public transport bus service levels and patronage would certainly be on average low outside capital cities, buses do play a large role in carrying children to school – particularly over longer distances in rural areas. The peak for bus usage in 1990 may be related to deregulation of domestic aviation, which reduced air fares by around 20%.

Melbourne has the lowest bus use of all the cities, but this likely reflects the extensive train and tram networks carrying the bulk of the public transport passenger task. Melbourne is different to every other Australian city in that trams provide most of the on-road public transport access to the CBD (with buses performing most of this function in other cities).

For completeness, here’s growth in light rail patronage:

Sydney light rail patronage increased following the Dulwich Hill extension that opened in 2014, while Adelaide patronage increased following an extension to the Adelaide Entertainment Centre in 2010.

We can sum all of the mass transit modes (I use the term “mass transit” to account for both public and private bus services):

Sydney is leading the country in mass transport use per capita and is growing strongly, while Melbourne, Brisbane, Perth have declined in recent years.

Mass transit mode share

We can also calculate mass transit mode share of motorised passenger kilometres (walking and cycling kilometres are unfortunately not estimated by BITRE):

Sydney has maintained the highest mass transit mode share, and in recent years has grown rapidly with a 3% mode shift in the three years 2016 to 2019, mostly attributable to trains. The Sydney north west Metro line opened in May 2019, so would only have a small impact on these figures.

Melbourne made significant gains between 2005 and 2009, and Perth also grew strongly 2007 to 2013.

Here’s how car and mass transit passenger kilometres have grown since car used peaked in 2004:

Mass transit use has grown much faster than car use in Australia’s three largest cities. In Sydney and Melbourne it has exceeded population growth, while in Brisbane it is more recently tracking with population growth.

Mass transit has also outpaced car use in Perth, Adelaide, and Hobart:

In Canberra, both car and mass transit use has grown much slower than population, and it is the only city where car growth has exceeded public transport growth.

Car ownership

The ABS regularly conduct a Motor Vehicle Census, and the following chart includes data up until January 2019.

Technical note: Motor Vehicle Census data (currently conducted in January each year, but previously conducted in March or October) has been interpolated to produce June estimates for each year, with the latest estimate being for June 2018.

In 2017-18 car ownership declined slightly in New South Wales, Victoria, and Western Australia, but there was a significant increase in the Northern Territory. Tasmania has just overtaken South Australia as the state with the highest car ownership at 63.1 cars per 100 residents.

Victorian car ownership has been in decline since 2011, which is consistent with a finding of declining motor vehicle ownership in Melbourne from census data (see also an older post on car ownership).

Driver’s licence ownership

Thanks to BITRE Information Sheet 84, the BITRE Yearbook 2019, and some useful state government websites (NSW, SA, Qld), here is motor vehicle licence ownership per 100 persons (of any age) from June 1971 to June 2018 or 2019 (depending on data availability):

Technical note: the ownership rate is calculated as the sum of car, motorbike and truck licenses – including learner and probationary licences, divided by population. Some people have more than one driver’s licence so it’s likely to be an over-estimate of the proportion of the population with any licence.

There’s been slowing growth over time, but Victoria has seen slow decline since 2011, and the ACT peaked in 2014.

Here’s a breakdown by age bands for Australia as a whole (note each chart has a different Y-axis scale):

There was a notable uptick in licence ownership for 16-19 year-olds in 2018. Otherwise licencing rates have increased for those over 40, and declined for those aged 20-39.

Licencing rates for teenagers (refer next chart) had been trending down in South Australia and Victoria until 2017, but all states saw an increase in 2018 (particularly Western Australia). The most recent 2019 data from NSW and Queensland shows a decline. The differences between states partly reflects different minimum ages for licensing.

The trends are mixed for 20-24 year-olds: the largest states of Victoria and New South Wales have seen continuing declines in licence ownership, but all other states and territories are up (except Queensland in 2019).

New South Wales, Victoria, and – more recently – Queensland are seeing downward trends in the 25-29 age bracket:

Licencing rates for people in their 70s are rising in all states (I suspect a data error for South Australia in 2016):

A similar trend is clear for people aged 80+ (Victoria was an anomaly before 2015):

See also an older post on driver’s licence ownership for more detailed analysis.

Transport greenhouse gas emissions

[this emissions section updated on 8 January 2020 with BITRE estimates for 1975-2019]

According to the latest adjusted quarterly figures, Australia’s domestic non-electric transport emissions peaked in 2018 and have been slightly declining in 2019, which reflects reduced consumption of petrol and diesel. However it is too early to know whether this is another temporary peak or long-term peak.

Non-electric transport emissions made up 18.8% of Australia’s total emissions as at September 2019.

Here’s a breakdown of transport emissions:

A more detailed breakdown of road transport emissions is available back to 1990:

Here’s growth in transport sectors since 1975:

Road emissions have grown steadily, while aviation emissions took off around 1991. You can see that 1990 was a lull in aviation emissions, probably due to the pilots strike around that time.

In more recent years non-electric rail emissions have grown strongly. This will include a mix of freight transport and diesel passenger rail services – the most significant of which will be V/Line in Victoria, which have grown strongly in recent years (140% scheduled service kms growth between 2005 and 2019). Adelaide’s metropolitan passenger train network has run on diesel, but more recently has been transitioning to electric.

Here is the growth in each sector since 1990 (including a breakdown of road emissions):

Here are average emissions per capita for various transport modes in Australia, noting that I have used a log-scale on the Y-axis:

Per capita emissions are increasing for most modes, except cars. Total road transport emissions per capita peaked in 2004 (along with vehicle kms per capita, as above).

It’s possible to combine data sets to estimate average emissions per vehicle kilometre for different vehicle types (note I have again used a log-scale on the Y-axis):

Note: I suspect the kinks for buses and trucks in 2015, and motor cycles in 2011 are issues to do with assumptions made by BITRE, rather than actual changes.

The only mode showing significant change is cars – which have reduced from 281 g/km in 1990 to 243 g/km in 2019.

However, the above figures don’t take into account the average passenger occupancy of vehicles. To get around that we can calculate average emissions per passenger kilometre for the passenger-orientated modes:

Domestic aviation estimates go back to 1975, and you can see a dramatic decline between then and around 2004 – followed little change (even a rise in recent years). However I should mention that some of the domestic aviation emissions will be freight related, so the per passenger estimates might be a little high.

Car emissions per passenger km in 2018-19 were 154.5g/pkm, while bus was 79.4g/pkm and aviation 127.2g/pkm.

Of course the emissions per passenger kilometres of a bus or plane will depend on occupancy – a full aeroplane or bus will have likely have significantly lower emissions per passenger km. Indeed, the BITRE figures imply an average bus occupancy of around 9 people (typical bus capacity is around 60) – so a well loaded bus should have much lower emissions per passenger km. The operating environment (city v country) might also impact car and bus emissions. On the aviation side, BITRE report a domestic aviation average load factor of 78% in 2016-17.

Cost of transport

The final topic for this post is the real cost of transport. Here are headline real costs (relative to CPI) for Australia:

Technical note: Private motoring is a combination of factors, including motor vehicle retail prices and automotive fuel. Urban transport fares include public transport as well as taxi/ride-share.

The cost of private motoring has tracked relatively close to CPI, although it trended down between 2008 and 2016. The real cost of motor vehicles has plummeted since 1996. Urban transport fares have been increasing faster than CPI since the late 1970s, although they have grown slower than CPI (on aggregate) since 2013.

Here’s a breakdown of the real cost of private motoring and urban transport fares by city (note different Y-axis scales):

Note: I suspect there is some issue with the urban transport fares figure for Canberra in June 2019. The index values for March, June, and September 2019 were 116.3, 102.0, and 118.4 respectively.

Urban transport fares have grown the most in Brisbane, Perth and Canberra – relative to 1973.

However if you choose a different base year you get a different chart:

What’s most relevant is the relative change between years – eg. you can see Brisbane’s experiment with high urban transport fare growth between 2009 and 2017 in both charts.

Hopefully this post has provided some useful insights into transport trends in Australia.


Update on Australian transport trends (December 2018)

Fri 28 December, 2018

For more recent trend information – skip to the December 2019 update on Australian transport trends.

Each year, just in time for Christmas, the good folks at the Australian Bureau of Infrastructure, Transport, and Regional Economics (BITRE) publish a mountain of data in their Yearbook. This post aims to turn those numbers (and some other data sources) into useful knowledge – with a focus on vehicle kilometres travelled, passenger kilometres travelled, mode shares, car ownership, driver’s licence ownership, greenhouse gas emissions, and transport costs.

Vehicle kilometres travelled

Road transport volumes are rising, and most of the traffic is of course cars:

Here’s the growth by vehicle type since 1971:

Light commercial vehicle kilometres have grown the fastest, curiously followed by buses (although much of that growth was in the 1980s).

Car kilometre growth has slowed significantly since 2004.

In fact, on a per capita basis car use peaked in 2004 and then declined until 2014, with a little growth since. Here’s the Australian trend (in grey) as well as city level estimates to 2015 (from BITRE Information Sheet 74):

Technical note: “Australia” lines in these charts represent data points for the entire country (including areas outside capital cities).

Darwin has the lowest average which might reflect the small size of the city. The blip in 1975 is related to a significant population exodus after Cyclone Tracey caused significant destruction in late 2014 (the vehicle km estimate might be on the high side).

Canberra, the most car dependent capital city, has had the highest average car kilometres per person (but it might also reflect kilometres driven by people from across the NSW border in Queanbeyan).

The Australia-wide average is higher than most cities, with areas outside capital cities probably involving longer average car journeys and certainly a higher car mode share.

Passenger kilometres travelled

It’s also possible to look at car passenger kilometres per capita, which takes into account car occupancy – and also includes more recent estimates up until 2017:

While car passenger kilometres per capita also peaked in 2004, they have increased slightly in recent years in Perth, Adelaide, Brisbane, and Sydney.

BITRE also produce estimates of passenger kilometres for other modes (data available up to 2017 at the time of writing).

Rail use is highest in Sydney followed by Melbourne. You can see two big jumps in Perth following the opening of the Joondalup line in 1992 and the Mandurah line in 2007.

(note: this includes both public and private bus travel)

Australia-wide bus usage is surprisingly high. While public transport bus service levels and patronage would certainly be on average low outside capital cities, buses do play a large role in carrying children to school – particularly over longer distances in rural areas. The peak for bus usage in 1990 may be related to deregulation of domestic aviation, which reduced air fares by around 20%.

Darwin saw a massive increase in bus use in 2014 thanks to a new nearby LNG project running staff services, while investments in increased bus services in Melbourne and Brisbane in the first decade of this century led to significant patronage growth.

We can sum all of the mass transit modes (I use the term “mass transit” to account for both public and private bus services):

We can also calculate mass transit mode share of motorised passenger kilometres (walking and cycling kilometres are unfortunately not estimated):

Sydney has maintained the highest mass transit mode share, while Melbourne made significant gains between 2005 and 2009, and Brisbane also grew strongly 2007 to 2013.

Here’s how car and mass transit passenger kilometres have grown since car used peaked in 2004:

Mass transit use has grown much faster than car use in Australia’s three largest cities. In Sydney and Melbourne it has exceeded population growth also.

Mass transit has also outpaced car use in Perth, Adelaide, and Hobart:

In Canberra, both car and mass transit use has grown much slower than population, and it is the only city where car growth exceeded public transport growth between 2004 and 2017.

Car ownership

The ABS regularly conduct a Motor Vehicle Census, and the following chart includes data up until January 2018.

Technical note: Motor Vehicle Census data (currently conducted in January each year) has been interpolated to produce June estimates for each year.

Car ownership has continued to rise slowly in all states – except Victoria, which is consistent with a finding of declining motor vehicle ownership in Melbourne from census data (see also an older post on car ownership).

Driver’s licence ownership

Thanks to BITRE Information Sheet 84, here is motor vehicle licence ownership per 100 persons (of any age) going back to 1971:

Technical note: the ownership rate is calculated as the sum of car, motorbike and truck licenses – including learner and probationary licences, divided by population. Some people have more than one driver’s licence so it’s likely to be an over-estimate of the proportion of the population with a licence.

There’s been slowing growth over time, but Victoria has seen slow decline since 2011.

Here’s a breakdown by age bands (note each chart has a different Y-axis scale):

Motor vehicle licence ownership rates have increased for people over 70 (presumably due to a healthier ageing population), and declined for people under 30.

Licencing rates for teenagers have been trending down in South Australia and Victoria recently, but not in other states:

The trends are mixed for 20-24 year-olds:

New South Wales and Victoria are seeing downward trends in the 25-29 age bracket:

Licencing rates for people in their 70s are rising in all states (I suspect a data error for South Australia in 2016):

A similar trend is clear for people aged 80-89 (Victoria was an anomaly before 2015):

(see also an older post on driver’s licence ownership for more detailed analysis)

Transport greenhouse gas emissions

Australia’s domestic non-electric transport emissions have increased steadily since 1990 and show no signs of slowing down, let alone declining (latest data at the time of writing is up to June 2018):

Depending on how you disaggregate total emissions, transport is the second largest sector and the fastest growing.

Here’s breakdown of transport emissions (detailed data only available to 2016 at time of writing):

And the growth in each sector since 1990:

Domestic aviation has had the fastest growth, followed by buses. In more recent years rail emissions have grown strongly (note: most of this is rail freight as the vast majority of passenger train movements are electric). Car emissions have grown 27%, but make up the largest share of transport emissions.

Here are per capita transport emissions for each state:

The data is a bit noisy (largely due to fluctuations in aviation emissions). Here are road emissions per capita:

In 2016 there were sharp increases in Western Australia, Queensland and the Northern Territory, while most other states appear to be on a downward trend.

Car emissions per capita have been generally trending downwards in most states, again except Queensland, Western Australia, and the Northern Territory:

Of course if we are to avoid dangerous climate change, total emissions need to reduce substantially, not just per capita emissions!

It’s possible to combine data sets to estimate average emissions per vehicle kilometre for different vehicle types:

It’s difficult to see any significant reductions in emissions intensity, while average bus emissions intensity has increased recently (not sure why). Average car emissions have fallen slightly from 281 g/km in 1990 to 244 g/km in 2016.

However, the above figures don’t take into account the average passenger occupancy of vehicles. To get around that we can calculate average emissions per passenger kilometre for the high person-capacity modes:

Of course the emissions per passenger kilometres of a bus or plane will depend on occupancy – a full aeroplane or bus will have likely have significantly lower emissions per passenger km. Indeed, the BITRE figures imply an average bus occupancy of around 9 people (typical bus capacity is around 60) – so a well loaded bus should have much lower emissions per passenger km. The operating environment (city v country) might also impact car and bus emissions. On the aviation side, BITRE report a domestic aviation average load factor of 78% in 2016-17.

Cost of transport

The final topic for this post is the real cost of transport. Here are headline real costs (relative to CPI) for Australia:

Technical note: Private motoring is a combination of factors, including motor vehicle retail prices and automotive fuel. Urban transport fares include public transport as well as taxi/ride-share.

The cost of private motoring has tracked relatively close to CPI, although has been trending down since around 2008. The real cost of motor vehicles has plummeted since 1996. Urban transport fares have been increasing faster than CPI since the late 1970s.

Here’s a breakdown of the real cost of private motoring and urban transport fares by city (note different Y-axis scales):

Urban transport fares have grown the most in Brisbane, Perth and Canberra – relative to 1973.

However if you choose a different base year you get a different chart:

What’s most relevant is the relative change between years – eg. you can see Brisbane’s experiment with high urban transport fare growth between 2009 and 2017 in both charts.

To illustrate the data visualisation problem of choosing a base year – here is the same data for every base year between 1973 and 2018:

Hopefully this post has provided some useful insights into transport trends in Australia. A future post might examine the relationships between the data sets further.