Here at VISOR, we argue—as the world’s leading transport scientists have argued for decades—that building more roads and bridges won’t solve traffic congestion, and in fact often makes it worse. If you pay close attention, you might be rankled by another disturbing conclusion of that argument: If building more road capacity can worsen traffic congestion, are you also saying that reducing road capacity can improve it? Are you insane?!
Actually…sometimes, that’s exactly what happens, and closing roads to cars could be one of the most powerful techniques we can use to fight the war on traffic. Let me tell you why.
On the face of it, it does sound crazy: When cars seem to pack our five- and eight-lane roads to the gills, how can the situation get better with less road? Turns out the effect known as induced demand—where more road invites more people to drive on it—also works in reverse. The less road there is, the less people want to go out and drive, meaning fewer cars on the road and less congestion, pollution and accidents. This might sound like a “duh” conclusion. Is it really good if people can’t drive to work or business anymore? When induced demand works in reverse, the first trips to “evaporate,” as transport scientist Paul Lecroart puts it, are low-urgency trips such as people traveling for nonessential purposes, or those who can afford to travel at different times.
There are a few catches here. The first is that the public’s expectations have to be well-managed. Communicating a carless street project to motorists ahead of the closure lets people adjust their travel plans ahead of time, making for much smoother implementation. The other caveat is that closing streets to motor-vehicle traffic needs to be backed up by investment in walking, cycling and public transit. It’s not so great if “less car traffic” means that someone who previously drove to a job has to quit because he has no feasible alternatives following the closure. However, if that person can now cycle or take quality public transit to reach his destination, then the street closure doesn’t hurt him, and now benefits all the other travelers on the rest of the route he once took.
Another mechanism that causes road closures to reduce congestion is a strange, lesser-known phenomenon called Braess’s Paradox. A simple explanation goes something like this: Adding links to the road network can worsen congestion if they direct traffic toward roads that congest more easily. The effect of Braess’s Paradox can happen independent of “reversed induced demand,” so it’s something decision-makers should keep in mind when examining proposals to close or open streets to traffic—such as the proposal to open all village roads to car traffic. Braess’s Paradox can turn that sideways quickly.
Closing streets to motor-vehicle traffic needs to be backed up by investment in walking, cycling and public transit
Reversed induced demand and Braess’s Paradox are the reasons that permanent carless street projects such as the Cheonggyecheon stream and linear park in Seoul never cause the Carmageddon result which detractors say are inevitable. One city that has been successful at creating carless streets is Pasig City, which has been running carless days with the cooperation of some of its barangays since 2014, and now has regular car-free weekend days in five locations all over the city.
Recently, Pasig City, together with Barangay San Antonio, ran an experiment by closing part of Pearl Drive to traffic on January 25, a Friday, instead of the usual weekend closure. The experiment was spurred by a petition raised by Friends of Pearl Drive, a community organization, to Mayor Bobby Eusebio of Pasig City, who approved the trial. While weekday closures are commonplace in the provinces for fiestas and funeral processions, they’re almost unheard of in busy parts of Metro Manila such as Ortigas Center, where Pearl Drive is located. The objective of the petition, according to the petitioning organization, was to give people a feeling of peace and safety while walking on the street, versus being regularly near-missed by rushing cars.
On cue, dissenting comments poured, as though closing a street on a Friday was the end of the world, and businesses along the street would go under. On the contrary, traffic monitoring during the closure showed that there was no major effect on congestion, and sales of some businesses actually improved because Pearl Drive was turned into a destination that attracted more foot traffic. Parents brought their children out to play and ride bikes, simple joys that are rarities for most families in Metro Manila these days. Most important, the public got a taste of just how good a street closure can be. Pearl Drive will be regularly closed to motor vehicle traffic on weekends while more data is collected about weekday closures.
The point is that, sometimes, we don’t need to build our way to traffic solutions that take months and years to get anywhere. Sometimes all you need is the will to make your street a more humane place. Get in touch with your local government about making a street car-free for a day. Who knows? You could be the one to win the war on traffic in your neighborhood.
DISCLOSURE: The author currently heads Pasig Transport, Pasig City’s initiative to fight the war on traffic by implementing sustainable transportation practices.