Questioning road-widening as the main solution to traffic

Metro Manila is a bustling and bursting metropolis of over 24 million people. Among the mounting challenges faced by the metropolis, chief among them is moving people efficiently amid rising road congestion. Why are the streets of Metro Manila becoming more congested in the first place? Is there truly a way to decongest a city still steadily experiencing urban growth?

In his paper Practical Strategies for Reducing Congestion and Increasing Mobility for Chicago, Samuel Staley defined congestion as an event wherein the supply of road space can no longer keep up with the increasing number of vehicles. Metro Manila’s congestion problem especially exemplifies Staley’s definition of the word: there are in fact more vehicles plying the metropolis’ streets than what the network can appropriately manage.

Given the definition of the word, it seems almost intuitive to deduce that augmenting road supply in the form of road widening would ease congestion. After all, conventional knowledge tells us that if demand for a product is increasing, then the obvious solution would be to correspondingly increase its supply. Moreover, it does no benefit that we have placed private car ownership on a pedestal since the dawn of our postcolonial obsession with the American Dream, which perhaps reveals where the problem lies. Our fixation on the private vehicle as the ideal mode of transport has seeped its way through not only our personal consumption choices, but also in the way policy makers have evaluated what is good for our cities. Instead of channeling investment towards infrastructure that enhance the movement of people, projects have received the government’s go-signal often on the basis of its ability to improve vehicular travel.

This practice has led to no less than the country’s widest highway: Commonwealth Avenue, the seventh radial road in Metro Manila’s arterial road system and the main corridor connecting the northern residential districts of Quezon City to the rest of the capital. On its widest section, the highway houses 18 mixed-traffic lanes. Despite its unparalleled road capacity, the corridor remains notorious for severe traffic and for being home to the city’s worst carmageddon ordeals, especially during weekend peak hours. The same is true for some of the world’s widest highways that hosts the worst traffic bottlenecks in their respective cities: from Houston’s 26-lane Katy Freeway to Beijing’s 50-lane G-4 Expressway. These all provide proof that a wider road does not necessarily result in less congestion.

There is a reason road supply is not able to keep up with the demand for its use: that is, in the case of transportation, infrastructure creates or induces its own demand. The underlying concept is called induced or latent demand, a phenomenon wherein demand for a certain good is generated as its supply increases. According to an article published by the LA Times, this is best understood when we visualize traffic as gas that expands and fills the space of its container, instead of the traditional engineering perspective of likening traffic to liquid, which merely follows its vessel’s shape. Although some form of decongestion may be experienced immediately after a road-widening project, it leads to generating more demand for road use. An increase in vehicular traffic will then create the need to augment road capacity all over again. In essence, building more car infrastructure will result in more car traffic.

This paints a powerful image because it shows us that our mobility has in effect been shaped by the infrastructure we have built — and that if we have built our way into the crisis we now experience daily, we can also build our way out of it.

The light at the end of the tunnel is that induced demand works the same way for all other transit modes. When a bike network is installed, more people start to bike; when a sidewalk is widened, more people tend to walk; when a bus service is augmented or improved, more people start taking public transport. Shifting people from depending on private vehicles to using more sustainable transit modes such as walking, cycling, and public transport is key to solving congestion because it optimizes the use of the limited road space available by moving the most number of people in the least amount of space.

Truth is, congestion is but a symptom of inefficient mobility. Going back to our previous example, according to counts by the Metropolitan Manila Development Authority in 2018 for Commonwealth Avenue, private transit modes (i.e. cars, motorcycles, and taxis) accounted for 84.7% of the corridor’s annual average daily traffic (AADT) while only carrying 39.7% of people that traverse it. On the other hand, public transit modes (i.e. buses, jeepneys, and UVs) carried 58.4% of the corridor’s commuters while only contributing 12.7% to traffic. The solution is clear: if we want to sustainably reduce congestion along roads like Commonwealth Avenue, we must focus on moving people more efficiently by building infrastructure for sustainable transit modes.

Unfortunately, although we hear the slogan Move People, Not Cars bannered as the government’s new policy direction for transportation, traditional car-centric policies and projects continue. The practice of road-widening remains to be the arsenal of choice amidst the mobility crisis — often in the name of an additional car lane, but at the expense of decent sidewalks. Talks of building elevated expressways and flyovers to solve the city’s most congested roads are the ones gaining traction, yet low hanging public transport improving initiatives are shelved. Conversely, to give way to private vehicles, public utility vehicles are kicked out of primary thoroughfares and forced to take longer routes to their destinations. Instead of providing dedicated space for two-wheelers to ensure the safety of their riders, personal mobility devices (i.e. bikes, e-bikes, and electric scooters) are simply banned from car-dominated roads without being given viable alternatives.

Mobility is not a slider that lives on the extremes; so the alternative is not for the exclusion of private vehicles but for the reduction of dependency on it — equitable distribution of road space that opens more options for people. The focus should be on optimizing road use by building infrastructure for more efficient transit modes, instead of building additional road space. That is where the opportunity to build our way out of the current crisis comes in.

Regina Mora, Ira Cruz, and Patrick Jalasco are members of AltMobility PH, a group of urban transport experts and ordinary citizens advocating sensible and humane transport policies. For more information regarding their advocacy for #CommutersNaman, visit:

https://www.facebook.com/AltMobilityPH.