Pedestrianization is an urban planning paradigm wherein infrastructure for people who walk, bike, and ride public transport is prioritized over that for private vehicles.
In layman’s terms, pedestrianization is “designing cities for people, not cars”.
The thought of going anywhere without using a car may sound like a pipedream, but cities such as Singapore, Copenhagen, and Iloilo have proven it to be possible.
Amazingly, there still exists opposition against pedestrianization.
Opposition’s reasonings include “nobody will use bikes because it’s too hot, polluted, and stressful” and “it’s better to widen roads to accommodate more cars.”
To that, I say pish-posh.
Environmental urban problems will disappear if a city prioritizes building infrastructure for pedestrians (including bikers) over private car owners.
Yes, I’m saying the excessive dependence on private cars are the reason for noise, high temperatures, air pollution, and traffic in cities.
I’m also claiming that prioritizing pedestrians will also benefit private car users.
Don’t believe me? Let me prove it with this causal loop diagram:
Explaining Feedback Loops
Before we delve into the explanation, I suggest checking out this article from The Systems Thinker.
The article runs you through the basics of creating a causal loop diagram, which is what I used to show the environmental benefits of pedestrianization.
If you’re too lazy to click that link, here’s a too-long-didn’t-read version:
We can better understand the cause-and-effect relationships of any system or phenomenon by identifying feedback loops.
What’s a feedback loop? It’s when one or more events cause and are caused by each other in an endless loop.
A change in Variable A causes a change in Variable B, which in turn causes a change in Variable A, ad infinitum.
Feedback loops can be either reinforcing (positive) or balancing (negative) loops.
“Positive and negative” doesn’t mean “good and bad”. It means ’building up on’ and ‘keeping in check’, respectively.
Developing a smoking habit is an example of a reinforcing loop. The more you smoke, the more nicotine you allow into your brain. You build a dependence on nicotine, which results in your puffing one more stick.
Next thing you know, you’re a chain smoker.
Reinforcing loops are responsible for phenomena such as habit formation, population growth, and economic collapse.
An example of balancing loops is drinking water when one is thirsty.
The thirstier you are, the more water you drink. But when you drink lots of water, your thirst disappears, which means you’ll stop drinking water. But not drinking water means you’ll become thirsty again.
You bounce back between states of thirst and non-thirst.
Balancing loops are responsible for phenomena such as predator-prey interactions, several human bodily functions, and ecosystem stability.
Now we got that out of the way, let’s get on with explaining the causal loop diagram.
To help you keep track which part of the pedestrianization diagram I’m talking about, balancing loops are labelled Bx, and reinforcing loops are labelled Rx, where ‘x’ is the loop number.
Okay, let’s take a close look at the diagram:
The Never-ending Cycle of Road Widening
When people are driven to use cars, obviously the volume of cars on the road increases, which leads to road congestion, which may discourage car use (B2).
With high road congestion comes the demand for more roads. The city hall can increase road space through road widening and building flyovers, which could alleviate traffic (B1).
Between these two balancing loops, does that mean increasing the amount of road space is a sustainable solution to traffic?
Hell no.
Why? Because although increasing road space may ease road congestion, it also encourages people to drive more, hence use more cars, which leads to greater demand for more road space (R1).
Build more roads, encourage more car use, get more traffic.
As you can see, no amount of car-friendly infrastructure can satisfy the ever-increasing demands of car users.
Worse, the need to build more roads forces cities to sprawl out, i.e. urban sprawl, which means more built-up areas that absorb lots of heat, causing an urban heat island effect.
Heat, Noise, and Smog
Increasing car traffic volume leads to more than just congestion.
More people using cars means greater consumption of gasoline and other fossil fuels. This means more cars exhausting fumes, polluting the air.
A city with heavily polluted air does not promote a good experience for pedestrians, bikers, and public transport riders. In such a scenario, people would rather have their own vehicles (R4).
Burning fossil fuels also results in emissions of greenhouse gases (or GHGs), which are responsible for the greenhouse effect, which increases global temperatures.
The urban heat island effect exacerbates outdoor urban temperatures that are already high and well beyond comfortable levels. Again, not ideal for pedestrians, who’d probably prefer airconditioned car interiors (R5).
If those aren’t uncomfortable enough, the more cars there are on the road, the more noise produced. With high levels of urban noise pollution, people would rather drive than put up with the stressful outdoor environment (R3).
The worst part of this is that these three loops are reinforcing.
Temperature, noise, and pollution levels will increase faster and faster the longer this cycle is allowed to persist – especially when a governing body decides to build more infrastructure beneficial only to private cars.
The Sustainability of Pedestrianization
Fortunately, the same mechanism that exponentially raises high pollution levels can also bring it down exponentially.
Let’s say a city decides to allot more space and budget to pedestrian infrastructure by converting 2 out of 6 lanes of road into bike lanes and sidewalks (R2).
With less road space, you’d think that traffic would get more congested.
But, because people see only 4 lanes remain, they might think twice to bring their cars. Ergo, there’ll be less cars on the road!
And, through the R1 feedback loop, demand for roads will diminish, freeing up more road space, which further reduces traffic congestion.
To add, the R3, R4, and R5 feedback loops will see to it that pollution levels and high temperatures progressively go down.
As they do, the city becomes more hospitable to pedestrians, who will now have the option to not drive to their destination.
Best part is the more road space freed up, the more pedestrian space. The actual area required by sidewalks, bike lanes, and public transport facilities is significantly less than that required by flyovers and highways.
So, what to do with that extra space? Green space, of course!
Because more areas that can be allotted to greenery, there can be more vegetation such as trees, the foliage of which can dampen sound and reduce noise pollution.
Trees can also bring down high urban temperatures in several ways.
Through carbon sequestration, urban trees can bring down the amount of GHGs in the atmosphere, which helps mitigate the greenhouse effect.
Sunlight cannot reach concrete surfaces shaded by trees, resulting in no heat absorption. Trees can also directly cool the air through evapotranspiration, a process that entails releasing water as vapor from its leaves.
Through both processes, trees can mitigate the urban heat island effect, bringing outdoor urban temperatures to levels more suitable for pedestrians.
Greater atmospheric GHG concentrations lead to higher rates of carbon sequestration (B3), and higher temperatures increase evapotranspiration rates (B4).
Both balancing loops show the regulatory functions of vegetation, possible because there’s more available space for greenery through pedestrianization.
Conclusion
The causal loop diagram is complex, but far from complete.
Several socioeconomic benefits such as increased safety, greater sense of community, more employment opportunities, and better physical and mental health were left out on purpose.
Including them will involve creating a much, much more complex diagram!
Such is the case for complex systems.
Nonetheless, I hope you found this article and the diagram informative and inspiring. It’s truly amazing how much we can benefit from just valuing people more than we do mere hunks of metal.
If you have any questions or clarifications, don’t hesitate to comment down below. You can also contact me through here.
Thanks for your time, fabled readers!
Decosys 