Decarbonising transport

It’s not just about public transport

Decarbonising the public transport network is a good goal. I was pondering the history and recent progress.


  • Started as horse (1884), cable (1885, fuelled by coal) and electric (1889) trams
  • Horse trams phased out 1923 in favour of electric
  • Cable trams phased out 1940 in favour of electric (but some routes converted to buses, eg diesel)
  • All electric, and powered by renewables since 2019

Suburban trains (Metro)

  • Started as steam trains (1854)
  • Mostly converted to electric (1919 to 1929)
  • Some expansion of electric suburban services to take over from diesel trains: Pakenham line 1975, Werribee line 1983, Sunbury line 2002-2012, Craigieburn 2007
  • Stony Point line still runs as diesel
  • Renewable power planned for 2025

So with the exception of the Stony Point line and a handful of maintenance/works vehicles, the network will be zero emissions in the next couple of years.


  • Started 1912 using petrol buses, though there had been a short-lived steam bus in 1905-06
  • Mostly now diesel, but there have been some tests with hybrids, hydrogen and ethanol
  • Electric bus trials started in 2019, expanded in 2022
  • All new bus purchases to be zero emissions from 2025, though it appears no firm target around renewable power yet

The path forward is theoretically pretty straightforward: continue updating the fleet to electric (or other Zero Emissions vehicles such as hydrogen, to handle longer routes) and also work on moving power generation to renewables.

But they’ve only just begun. So far there are perhaps a few dozen electric buses, out of a fleet of perhaps a few thousand. And there are challenges with power and other upgrades needed for depots.

And if diesel buses will be being purchased up to 2024, given the long life of buses, it’ll take a while.

Electric bus

Regional trains (V/Line)

  • Started as steam trains, with the first regional line to Geelong in 1857
  • First diesel locomotives from 1952, with steam phased out mostly in the 1950s and 60s
  • Electric trains ran on the Gippsland line from 1953 to 1987
  • Today, the entire fleet is diesel, with new trains being ordered

New diesel trains are presumably more efficient than the old ones they are replacing.

But the lack of actual or planned progress to transition off diesel is a concern. It would be good to know that the government is planning long term to begin electrification, and/or testing of battery-electric trains or other technologies.

Other transitional options include dual-mode trains, with the busiest parts of the network electrified, something NSW is doing.

Decarbonising all transport

Decarbonising public transport is good, but there are reasons to be cautious about doing it too rapidly.

“The difference between whether somebody is in a car or a bus is a huge environmental factor we should be talking about,” (Christoph Spieler) says. “If we do electrification instead of growing service or ridership, then we’re actually making the planet worse off.”

Governing: The Rocky Road to Bus Electrification

Spieler’s point is a good one. After all, the PT system doesn’t act in isolation.

In Australia, transport is the 3rd biggest sector for emissions (tipped to become the top emitter in coming years), and according to this chart from the Climate Change Authority, about half of that is cars.

Chart showing transport emissions in Australia for 2020

Decarbonising transport can’t be left to switching to electric cars, because as Ketan Joshi notes, “even with aggressive incentives to get people to buy an EV for their next car, there are still many years between old and new cars for most people”.

He also notes that “An EV-only transport policy (even a perfect one) means an eventually-big but very slow reduction in emissions.”

Moving people from cars

A big part of the push to decarbonise transport must be a shift of more people out of cars to active and public transport. This happens by making it easier to walk and ride, and by increasing and improving public transport services.

Last month’s State Budget shows where things are going in Victoria. While there are some initiatives to provide a handful of additional or expanded services, the actual numbers (found in Budget Paper 3) for service kilometres seem to show this is mostly lost as a rounding error.

Total kilometres scheduled (millions)2021-22
Suburban trains (Metro)24.924.924.9
Regional trains and coaches (V/Line)27.527.527.5
Buses – metropolitan128.0130.5129.3
Buses – regional27.327.327.3

There’s a slight increase in metro bus kilometres (with a higher than expected blip this year), but it’s not yet delivering on the promises of the now two year old Bus Plan.

Tram and train services are not increasing. Hopefully we’ll see an upswing in some of these numbers in 2024-25, with extra V/Line weekend services funded, and the Metro tunnel expected to open sometime in 2025.

Frustratingly, even where there is not only demonstrated travel demand, but also public transport travel demand, there’s no push from government to further boost services, even on weekends and public holidays when much of the fleet sits idle.

Given recent and anticipated population growth, if service kilometres are static, we’re currently going backwards.

While the government has been investing in public transport infrastructure, and decarbonisation, this is a reminder that it still needs to do better on services (and freight).

The real key to reducing transport emissions isn’t just electric vehicles, it’s also fewer vehicles on the road, and people travelling more efficiently.

By Daniel Bowen

Transport blogger / campaigner and spokesperson for the Public Transport Users Association / professional geek.
Bunurong land, Melbourne, Australia.
Opinions on this blog are all mine.

13 replies on “Decarbonising transport”

With the buses, going electric will be a good thing, but we need to encourage use of buses, as they tend to be the only mode of transport available in many areas; so I would suggest increasing frequency on routes such as 800 and introducing weekend services on said route (as suggested by Peter Parker from Melbourne on Transit) as well as doubling the bus frequency in the outer metropolitian areas (many have hourly frequency on weekends or none at all). And on major events (such as New Years’ Eve), doubling Night Bus would be useful for those who head out on New Years’ Eve such as Yours Truly (half hour frequency on New Years’ Eve would encourage people to use public transport on the busiest night of the year instead of driving to the station).

The Gippsland line was electrified to Traralgon until the late 80s, but the overhead was still up as far as Warragul until circa 1998, with electric suburban sets running (on weekends or just Sundays IIRC), usually with 3-car Comeng sets but apparently the odd Hitachi occasionally ran down there, most likely with 6 carriages.

As I recently blogged about, how curious it is that the Lilydale and Belgrave lines have a 30 minute service on weekdays and a 20 minute service at weekends. I was surprised that I had to wait 15 minutes at Box Hill for a train to the city on a weekday, but weekends, it is only a 10 minute wait.

To be pedantic “suburban” Melbourne still has plenty of diesel trains – just look at Deer Park, Caroline Springs, Tarneit and Wyndham Vale which rely on V/Line services.

Only if you accept the notional matching of electricity demand to renewable generation – which used to have a degree of legitimacy when there was very little renewable generation and if it was all bought up then more would have to be installed. We’re past that stage. Unless the renewables are being matched to demand in real time, it’s meaningless to assert that all your electricity consumption is renewable.
I wonder if these diesel buses and trains still being purchased today are capable of running on an algae-derived biofuel or anything of that nature.

A policy failure when Ventura Bus Lines now has 13 electric buses at their Ivanhoe depot yet only 1 out of 6 their routes serving Northland, LaTrobe Uni and Coburg runs on Sundays ????⚡

Routes 526, 548, 549, 550 & 551 still lack Sunday timetables & finish around 7:30pm weeknights

And no sign of anything in state budget to fund Victoria Bus Plan improvements in middle suburbs

Metro trains network will be *net* zero emissions in the next couple of years, not absolute zero. That’s because the contracted volume of renewable generation will match Metro trains demand, but the timing of generation and consumption won’t align, so it’s a net zero commitment not an absolute zero commitment.

Unlike most other Australian capital cities, Melbourne missed out on the trolleybus era. Given that they retained trams, I wonder whether they would have retained trolleybuses? If you’re looking for figures, there are about 2,700 buses serving Melbourne (about half the number there are in Sydney). In NSW they’re finding there’s an issue with power infrastructure for electrifying rural services and the target date for that is in the 2040s.

In 1991, when Benders Busways in Geelong was still owned by the Bender family, they trialled three Mercedes Benz buses powered by compressed natural gas. They must have been reasonably successful because the fleet was eventually expanded to nine. After Benders sold out to Keffords in 2000, those buses seemed to disappear.

I must draw attention to your statement that “suburban rains” (yes, you do then say “Metro “) is due to be emission Free by 2025….. Surely the elephant in the room is Tarneit and Wyndham Vale, surely, by definition, suburban rail stations?? Yes, they were an “added benifit” of the regional rail upgrade, but one of Melbourne’s rare suburban rail expansions in recent years was done with DIESEL TRAINS….. And, as you further comment, no hint of possible electrification of these busy routes in the foreseeable future….

As has been eluded to in a couple of posts, it’s deceptive to describe any single electricity user as being “all renewables”. Every user is consuming electricity based on the overall power generation mix, as renewables won’t be switched off or ramped up based on which users are creating demand.

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