Advocacy: Why We Do What We Do
Mike Watson | Advocate Coordinator , Pedal Power ACT
Chapter 2: Traffic Congestion and ‘Induced Demand’.
I really don’t like being stuck in congested traffic. That’s one of the reasons why I like living in Canberra.
So, what can be done about congested traffic? Well, here are a couple of options:
More roads could be built, so there’s more room for all the cars heading in the same direction…
Or, I could find a different way to get to where I want to go.
Let’s flip these two options into questions.
Take the second option first, and ask:
What would it take for me to want to find a different way to travel?
Okay, I don’t like congestion. So if the journey is regularly too congested, I might look for an alternative – maybe taking the train instead. But what if I’m not the only one thinking this way?
Let’s say half the drivers on this route suddenly decide to switch to the train. The road would become less congested. Car journeys would then become faster, and some of those new train passengers might go back to driving. Eventually, traffic flows find a kind of balancing point: the road is still busy with some congestion, but not quite enough to make the average car driver switch to the train. So, the average driver remains a bit frustrated and grumpy, [1] but not enough to change their behaviour – on average.
You can tweak the scales of what persuades someone to drive or take the train. You can increase the price of train tickets, or raise car parking fees to over $100 per week (could you believe that?).
If congestion is managed this way, it becomes easier to see that building an extra lane simply encourages more people to drive – until congestion returns to the same level as before. You just end up with more equally grumpy drivers using a slightly wider, but still congested road.
So now that we know adding extra road lanes doesn’t reduce the average delay in regular congestion, what can we do to reduce delays on this route?
We can provide more transport alternatives that reduce the cost (in money, time, and other grumpy-making factors), tempting some drivers to switch to different travel modes based on their individual needs. Unlike the extra road lane – which just leads to more congested driving – a wider range of viable transport options means some drivers actually become less grumpy, as they find a mode of travel that suits them better. That means fewer drivers sitting in congested traffic.
Does this method work?
Let’s look at a few examples:
Yes! (a very detailed 25-minute view)
Yes! (mild language alert – 5-minute view)
Yes! (politer example – 8-minute view)
Yes! (road engineer’s point of view)
Yes! (Australian example – 1-minute view)
Yes! Take Stage 1 of the light rail construction, for example. During the building of the light rail between Gungahlin and the City, one lane of Northbourne Avenue was closed in each direction for two years – turning it into a 4-lane road instead of the usual 6. Over time, traffic flows adjusted, and regular commuters got used to the different transport options available.
When the lanes were finally re-opened, there was no change in how long it took uncongested traffic to travel between EPIC and the City. There was also no detectable difference in the average delay during peak-hour congestion. A 50% increase in road lanes made no difference to the driving experience – but there were 50% more cars sitting in traffic. Most importantly, drivers didn’t get anywhere any faster once Northbourne went back to 6 lanes!
So, why do advocates encourage more transport diversity instead of just building more car lanes?
Because riding bikes is good for nearly everyone – and when more people choose to ride, fewer people need to drive. That reduces traffic and improves public health. It’s a win-win!
And economically, it’s far cheaper to build and maintain networks for bikes and active travellers than to maintain our road network. The savings from making active travel a better choice for short trips are enormous – another win-win!
That’s why we advocate for more diversity in transport infrastructure instead of more car-only lanes. It’s better for everyone. The politicians know it, and we’ll keep explaining the benefits to the community.
[1] ‘Grumpiness’ is what a bike rider might think of when an economist calls the condition a ‘perceived cost’. An economist would ask, ‘How much would you be prepared to pay to avoid this thing?’ What is the value of your time sitting in the traffic jam, and the value of avoided frustration and inconvenience from congestion-based delays? Subtract the value of any benefits, such as dropping any family off at school on the way (unless you would still have the benefits when using an alternative travel mode).
