Australasian Science: Australia's authority on science since 1938

Driverless Cars Will Not Solve Traffic Congestion

By Graham Currie

Driverless cars are yet another lie we’ve been told about reducing congestion in our cities.

In 2005, Australian traffic congestion cost $9.4 billion, and by 2020 it will grow to $20.4 billion. Melbourne’s current population of five million will increase to eight million by 2050.

The pressure this places on transport is untenable. To my mind the solutions we have been sold are lies. Almost all of our investments have been roads, largely because most of us drive. We have invested billions in upgrading freeways, but did we ever solve the congestion problem, or did the problem get worse?

Isn’t it a lie to promote projects that don’t solve the problems they were built for?

We are right to be cynical of current “solutions”. Transport science provides clear evidence that increasing road capacity increases road travel, so do we really need more cars?

Unlike all other world supercities, Australian cities still prioritise road investment over public transport. Sydney and Melbourne are building our first long-overdue underground metros, each providing travel capacity equivalent to more than five separate freeways.

Rail has a clear advantage for supercities needing vast travel scale, and the world’s supercities have substantially more rail than Australian cities do.

Catering for vast growth means being super-efficient in the use of space, so we need more people to share high-capacity vehicles to make cities work.

New lies are told when we ask technology to solve the problem, such as “shared mobility” modes like Uber, car share and bike share. While smart technology is user-friendly, these modes are a new lie to add to the old.

Let’s start with the phrase “shared mobility”. These transport modes rarely involve sharing. The average number of passengers in an Uber is 0.6. In other words, Ubers run empty 40% of the time, adding to already congested roads.

The other lie is that shared mobility is growing, and hence solving urban problems. Some 76% of Melbourne commuting is by private car, and sharing in cars has consistently fallen for decades.

Melbourne has the lowest car occupancy of all Australian cities, so we have been investing most of our money in solutions to carry fewer and fewer people on increasingly congested freeways. We have been investing in a lie.

The latest technology “solution” is the so-called driverless car – perhaps the biggest lie of all. While the technology is impressive, will they really help relieve traffic congestion? Most research suggests that if they ever work in urban streets, they will boost car travel, as those who can’t drive would now be able to travel.

And there is no evidence people will share them. Why would you share a car alone with a stranger?

Then there is the new problem: car occupancy in driverless vehicles can go … below one! Do we want to invest in driverless cars carrying nobody on bigger roads with more cars that are increasingly congested?

Am I wrong to think this is not a smart way to use expensive technology and infrastructure?

The final lie is that public transport is old and outdated, and that new mobility modes and driverless cars are the way of the future. Only public transport has the capacity to carry the volume of travel in Australia’s megacity futures.

Public transport has in any case led all driverless vehicle technology. More than 40% of all trains in Asia are driverless, and Sydney will soon have a new driverless train. These are real systems reliably carrying hundreds of millions of passengers every day.

So why are there so many lies around transport futures? For a century, we have purchased private cars to provide freedom in cities, feeding a powerful global industrial and political machine that has grown in support. That freedom is no longer possible, and new lies are derived from an industrial system seeking to justify and protect its future.

It’s time for the truth when discussing Australia’s urban transport future.


Professor Graham Currie FTSE is the Director of the Public Transport Research Group at Monash University, and chairs the Academy’s Infrastructure Forum.