Annual average per capita travel in State capitals, car vs public transport (source data: BITRE Yearbook 2013)

The exhibit shows changes in the level of travel by car and public transport in the six Australian state capital cities over the last 40 years.

It’s clear we’re motoring a great deal less than we used to. Data collected by the Bureau of Infrastructure, Transport and Regional Economics shows growth in per capita driving started to level off in the mid-nineties and began to fall from around 2004-05.

But it’s also evident from the exhibit that very little of the decline in driving in Australia’s capitals can be explained by increased use of public transport. As I’ve discussed before, it doesn’t have much to do with the increased attractiveness of inner city living either.

The decline is occurring to varying extents in a number of developed countries and is strongest amongst millennials, particularly young men (see What’s really putting the brakes on millennial’s driving?).

There are many plausible explanations for the fall (see Why are Australians driving less than they used to?), including greater difficulty of obtaining a driver’s license; travel saturation; increased traffic congestion; and more.

Structural causes seem to have strong explanatory power. In their study of the travel behaviour of 20-29 year olds in six developed countries (see Are millennials driving less?), Kuhnimhof et al concluded the key explanations for the reduction in driving are more young adults in tertiary education, lower workforce participation, and starting families at a later age.

It’s probable all these factors contribute to varying extents, but I suspect the key explanation is the obvious one: we’re increasingly substituting electronic communications for driving; we’re making fewer trips.

For those with the ability to exploit the potential of technology, the warrant for driving is considerably weaker than it was 10 years ago. More and more transactions can now be done from the workplace or home (or anywhere) without the need for a travel.

It’s possible, even likely, we’re only witnessing the start of a sustained downward trend in travel, especially driving.

Erik Brynjolfsson and Andrew McAfee argue in Race against the machine that firms and organisations have only started tapping the full potential of computing power to substitute for transactions and communications that currently require a physical presence.

They say we’re just entering the period of rapid exponential growth (“the second half of the chess board”) when the most far-reaching effects of increases in computing will have the largest effect.

Advances like the Google autonomous car, Watson the Jeopardy! champion supercomputer, and high-quality instantaneous machine translation, then, can be seen as the first examples of the kinds of digital innovations we’ll see as we move further into the second half – into the phase where exponential growth yields jaw-dropping results.

As was the case with earlier major technological advances like steam and electricity, business takes time to adapt its production and marketing models to the new technology. Recognising and exploiting the full potential of the technology starts slowly and then accelerates.

Eliminating the need for travel isn’t all one-way; some activities still rely heavily on face-to-face contact. Indeed, the increasing knowledge component in production means the need for physical proximity is increasing in some industries like finance; hence the (modest) revival of the CBD and public transport.

In these industries, electronic communications facilitate face-to-face contact and hence are a complement to, not a substitute for, activities that involve intense face-to-face interactions (see Why can’t Yahoos telecommute anymore?).

But the increased value of face-to-face contact only seems to apply to particular activities. It seems there’re many more transactions and pursuits – probably mostly outside work – that can be done without the need for travel and, hence, for driving.

It’s still very likely that cars and motorcycles will remain the main mode in our cities for many decades to come, but a continued decline in the per capita number of trips we make also seems likely (1).

This is the sort of issue strategic planners should be thinking much harder about. As noted here, Should strategic planning ignore the future?, it’s barely on the radar in some places. It’s not enough for a metropolitan strategic plan to merely note what’s happened historically; it should assess what’s likely to happen in the future, evaluate the implications, and specify what action should be taken.


  1. The experience in the US suggests the decline in per capita travel/driving is more likely the result of fewer trips rather than shorter trips.