Annual savings from commuting to the CBD from outer suburbs by 'light class' car versus using public transport and (a) still having a car at home or (b) owning no car. Source: data from Wang

New research estimates a Sydney worker living in the outer suburbs could save between $2,946 and $11,170 per year if she takes public transport to work in the CBD instead of driving a ‘light class’ car like a Toyota Yaris 1.3 litre hatch.

If she drives a behemoth such as a Toyota Landcruiser she’ll save between $9,171 and $18,606 each and every year by switching to public transport.

The study, Commuter costs and potential savings, got good coverage across the nation in the media last week because it had numbers for most capital cities. It was done for the Australasian Railway Association by Dr Jian Wang at the CRC for Rail Innovation, Southern Cross University

It compares the cost of commuting to the CBD by public transport against the cost of driving under two scenarios (1).

The smaller saving assumes the commuter has a car but leaves it at home and takes public transport instead. The larger saving assumes using public transport enables a commuter to live entirely car-free or avoid the cost of buying a second car.

I think the relevance of the higher estimate is somewhat limited in the case of outer suburban households because living without at least one car is very difficult and having two is a boon, particularly at night and on weekends. Practically every household already has at least one car and most have two or more (2).

But even the lower estimates are serious money. I don’t have any problems with Dr Wang’s numbers; they sound about right to me. Any outer suburbanite who drives to work must be mad, right?

However before readers conclude drivers living in the deep of suburbia are all thick as two planks (confirmation bias?), there are a number of points to consider.

First, the study is only about commutes to the CBD. Only a small proportion of metropolitan jobs are in the CBD and most workers already travel there by public transport. For example, Melbourne’s CBD (including Southbank, Docklands and Carlton) has 15% of metropolitan jobs. Cars only have around 20-30% mode share within walking distance of the rail loop.

Second, only a small proportion of outer suburbanites work in the CBD (and those that do tend to live in the more salubrious suburbs). The great majority work in the suburbs and commute via car.

Third, those who do work in the CBD already strongly favour public transport. Most use it because the CBD is the one place that’s well-served by trains and buses from the outer suburbs, particularly during rush hour.

It’s also a place where the car’s advantages are fettered by the length of the commute, traffic congestion and high parking charges.

Fourth, the tiny residual group that drives from the outer suburbs isn’t stupid. Its members don’t worry much about the cost of driving because in many cases their expenses are being met in whole or in part by their employer and the taxpayer e.g. parking.

They’re also usually well-paid professionals who can to some degree manage congestion e.g. by varying their arrival and departure times. Some also drive because they need to use a vehicle during working hours.

Others drive because it’s a convenient way to get to other activities before and/or after work e.g. study, child care, visiting parents or friends, sport. They calculate the aggravation and cost of driving to the CBD is worth it for the after-hours flexibility it provides.

Overall then, while Dr Wang’s comparison is interesting and accurate, in terms of changing behaviour it’s really only relevant to a very small number of current drivers.

The great majority of suburban commuters don’t realistically have the choice of swapping their car for a train or bus. Their commutes aren’t to the CBD but from dispersed origins to dispersed destinations. For them, the existing level of public transport service simply isn’t competitive with driving because trips takes longer.

A study by BITRE looked at all commutes, not just those to the CBD (see What is the cost of commuting by car versus public transport?). It estimated the total time outer suburban household members in Melbourne devote to commuting each week is 1,326 minutes by public transport versus 521 minutes by car. The value of this “saved” time makes up for the higher financial cost of driving (3).

_____________________________

  1. The study looks at a range of distances to the CBD, from 5 – 25 km. I’m only looking at 25 km, which for convenience I refer to as “outer suburbs”. In many cases the Growth Areas on the urban fringe are 30-50 km from the CBD.
  2. I appreciate some outer suburban households will feel better off financially if they’re able to avoid the cost of a second car. However many suburban households at all income levels prioritise expenditure on multiple cars because of the time saving/convenience they offer.
  3. The Australian Railway Association would’ve looked at CBD commutes because that’s the focus of radial train systems. Trains are mass transit so while they have a role, they’re not the main way to provide better public transport for intra-suburban commutes; buses are more suitable.