Will an airport rail link reduce GHGs?

Given the evident public interest in the idea of a rail link from the  CBD to the airport, I thought I’d look more closely at some of the key rationales for this project, starting with the claim that it would reduce greenhouse gas emissions.

Energy use and emissions (PTUA)

I’ve looked at this issue and, on my admittedly simple calculations, I conclude that the value of greenhouse gas (GHG) savings from a rail line is likely to be minor compared to the probable cost. There are far cheaper ways to offset equivalent emissions than building a rail line.

I looked at this by making the following simplifying assumptions.

First, I assume that a new rail line captures 20% of airport passenger traffic or five million of the current 25 million annual passenger movements at Melbourne Airport. This is double the share captured at either Sydney or Brisbane (around 10%), and almost three times the 7% estimated in feasibility studies.

Second, I assume that all of the current two million passengers using Skybus transfer to the new train (i.e. Skybus ceases to operate) and three million passengers transfer from cars, including taxis.

Third, I assume an average distance of 22 km from the CBD to the airport for bus and train. I assume that the combined average distance travelled to the airport by the cars and taxis that are replaced by train is 35 km. Read the rest of this entry »


Do the numbers support the Very Fast Train?

I’ve run some numbers on how a Very Fast Train in the Sydney-Melbourne corridor would stack up against planes in order to flesh out the questions I posed last week (Is the VFT all huff and no puff?).  I used a simple “back of the envelope” methodology adapted from that used by Harvard’s Edward Glaeser to evaluate high speed rail projects in the US (here).

I estimate the economic and environmental benefits of carrying all current Sydney-Melbourne air traffic by VFT rather than plane at around $840 million p.a. (although this does not include the cost of GHG emissions from construction of a rail line  – this would be large).

Table by Booz Allen

At first glance a VFT looks unpromising, since I estimate the capital cost of constructing and maintaining a VFT line from Sydney to Melbourne at about $1.5 billion per year. This is well in excess of the benefits.

However this assumes Sydney can accommodate passenger growth by using larger planes. It quite possibly can, but if it can’t and a second Sydney airport has to be built, a VFT starts to look viable if the cost of the airport were to come in at around $15 billion.

Let me emphasise that this is a simple analysis. I’ve left out many complications, including Canberra passengers and car traffic on the Hume.

The only environmental issue I’ve included is (operating) GHG. And of course I’ve made assumptions on things like construction costs and future interest rates.

Starting with capital costs, estimates of the cost to acquire land and construct a VFT line range from $14 to $82 million per km in Europe and the US (Japan is much higher because of earthquake risks). I assume a middling cost of $30 million per km, giving a total cost of $27 billion to build a 900 km line (the existing Sydney-Melbourne rail line is 950 km). I’ve assumed an interest rate of 5% p.a. and annual track maintenance cost of $124,000 per km. These assumptions give a total capital cost for the line of $1.5 billion per annum. Read the rest of this entry »


How important is transport in addressing climate change?

There are some salutary lessons in the Climateworks Australia report, Low Carbon Growth Plan for Australia, released publicly last month.

It reinforces the point I made on 10 March (We need to be more strategic about how we tackle GHGs) that it is important to think more deliberately about how to reduce carbon emissions. The estimated contribution that traditional “urban” policies in transport, buildings and land use planning can make to reducing emissions is relatively small, contributing together just 11% of potential savings, whereas the Climateworks report estimates power generation could contribute 31% and forestry 28%. Read the rest of this entry »