Caught (up) in traffic

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Monthly Archives: May 2021

On predicting how new developments will affect pedestrians

I’ve been involved in a number of traffic or transport impact assessment (TIA) projects in the past. In these assessments, not much is usually written about the impacts to pedestrians though we make sure that there is a section discussing their needs (e.g., sidewalks, crossings, footbridges). Unfortunately, even with specific recommendations, there is no assurance that the proponent will revise their designs. The typical TIA in the Philippines is undertaken after there have been architectural plans already prepared if not completed. By completed here, I mean they are practically final from the perspective of the client or proponent. The exception it seems is a big mall chain that seems to constantly revise their plans and for which our recommendations are almost always considered and incorporated in design.

I am sharing this recent article on the development of a new traffic model to predict the impacts of new developments on walkers.

Wilson, K. (April 26, 2021) “New Traffic Model Predicts How New Developments Will Affect Walkers,” StreetsBlog USA, [Last accessed: 5/12/2021]

From the perspective of doing TIAs, I think that there should be a conscious effort of including the needs of pedestrians (walkers) and cyclists in impact assessments. Too often, (and I too am guilty here), there is but a minor mention of their needs and recommendations can be disregarded by both proponents (e.g., little or no change in designs to accommodate pedestrian requirements) and the local government (i.e., no push to make sure pedestrian needs are addressed).

On the tech side, there is a local development that can be used for counting pedestrians and cyclists. The TITAN project funded by the DOST-PCIEERD developed a tool that can count pedestrians and cyclists in aid of studies involving them. Such tools can be useful for data collection regardless of whether there is a new project or a TIA being undertaken.

Do we miss commuting?

That’s the question asked in a recent article about commuting via public transport in the US. The pandemic has altered much of our lives including our typical daily travels between our homes and workplaces. Of course, the experiences vary in many countries and different towns and cities. However, we cannot deny that with the still developing information about the Covid-19 virus (i.e., how it is spread), many of us have had doubts about taking public transportation. For those who didn’t have much options for their commutes, they just had to do their part in observing health protocols and trust that the operators and drivers of public utility vehicles also do their part to sanitize vehicles.

Barry, D. (May 10, 2021) “No Scrum for Seats. No Quiet-Car Brawls. Is This Really My Commute?” The New York Times, [Last accessed: 5/11/2021]

How did your commutes change from what it was before the pandemic? Are you back to using public transport? Have you shifted to active modes like bike commuting? Did you go back to driving a car? Or are you still basically working from home most of the time? And did you miss how you were commuting before?

Not so fast…caution on data collection and reporting

I’ve seen posts where people have offered data on bicycle counts based on short period measurements (e.g., 5 to 15 minutes). They are quick to expand the counts to hourly values. So counting 10 bikes in 5 minutes (10 bicycles/5-minutes) is reported as 120 bikes/hour. I have seen some posts even stating that this was evidence of just how many people choose cycling for their commutes. While there is a significant increase in cycling volumes since last year (probably mainly due to the lack of public transport during this pandemic), their numbers still are quite low compared to both public and private transport users. It would be nice to know just how many people are cycling compared to pre-Covid levels. Here are some data I posted 5 years ago about traffic along the Iloilo Diversion Road where they have a wide bike lane along the northbound side of the highway. One wonders about the current numbers.

Figure 1. AM Peak hour traffic along the Iloilo City Diversion Road (ca. 2016)

Figure 2. PM Peak hour traffic along Iloilo City Diversion Road (ca. 2016)


It’s one thing to report and another to use the expanded value for modeling or analytical work. One basic reason why traffic scientists and engineers use the expanded value is because traffic volume is generally expressed in “vehicles/hour” as a standard unit. For certain purposes, this unit is converted to “pcu/hour” or “passenger car units per hour”. Flow rates may vary and are useful to describe the flow at specific times but the variation of flow is actually more important as this describes the behavior of traffic. I know, it reads or sounds like a car-centric unit of measurement, and it is. But that same comment can be made about currency and how the US dollar is being used rather than the Euro, the Yen, or the Yuan/Renminbi…if you get my point.

Perhaps a better argument is to use persons/hour/direction as the unit of measure if people cannot agree about using a specific vehicle type? That should be more acceptable to most people. But you need to have information about vehicle occupancies. Past studies in Metro Manila have established, for example, that on average the private vehicle occupancy is between 1.2 to 1.6 persons per car. This and other vehicle occupancies are multiplied to the various vehicle to estimate the number of persons in persons/hour/direction traveling along roads. This can be for the entire day or for peak periods. Note though that occupancy values will also vary according to time of day. The same calculations can be applied to rail and other modes as well.

The classic and popular graphic comparing the road space occupied by cars vs. spaces occupied by buses, motorbikes or bicycles, respectively is also inaccurate as these show capacity or the potential high value if certain modes are used. There will never be a 100% single mode choice especially for major roads like say the urban street network. Most people will choose their mode of transportation based on many factors including travel distance, time and cost. Those are the measurable factors. Others like comfort and convenience are also important and perhaps may have other factors substituting for them.

While I support cycling and the provision of bike lanes, there should always be a fair treatment of how data or information are gathered and presented. Otherwise, we are just misinforming people and generating hostility where cooperation or collaboration should be pursued instead. More work or effort towards convincing the general public and especially decision makers and movers in government and the private sector to effect changes in policies and infrastructure requires being collaborative rather than combative. That includes formulating ang communicating solutions rather than playing a blame game.

In defense of expressways

Expressways have been on the receiving end of criticisms and bad press lately mainly due to the recent much publicized proposal of a Pasig River Expressway (PAREX) by a private corporation. While I also do not agree with the alignment of this proposed tollway, I take exception to the generalization of expressways as sort of a manifestation of evil.

There seem to a lot of information being posted about and vs. expressways. However, it is important to sort through the hype as well as the misinformation that people tend to post about expressways. Yes, there are expressways being demolished or that have been demolished in other countries. These were probably so because they were ill-planned in the first place as are many other elevated pathways (e.g., poorly planned and designed footbridges), and many of the cities removing them have also developed their transport systems to be more efficient in terms of their people’s mobility. That is the case with Seoul and that certainly is the case for Tokyo. In fact, Tokyo had been moving their surface railways underground for the past decades. And now it seems they will be doing so for certain expressways. Does Tokyo have an efficient transport system? It does and perhaps is among the densest if not the most extensive rail and road system in the world.

It is important to have context to the matter. NLEX and SLEX, for example, were developed as relatively free-flowing, high capacity, high-speed roads that were the alternative to the national highways that directly connected many municipalities and cities. The latter had many intersections or junctions with other national roads as well as carry mainly local traffic including public transport such as tricycles and jeepneys. Expressways are built to be part of the primary arterial network and not as local roads. They are built for access rather than mobility.

From L-R: SLEX, Skyway, and the East Service Road. The Skyway connects the NAIA-X to the left and the NLEX connector section onwards through. SLEX eventually becomes the South Super Highway, which is an urban street.

So, are expressways anti-pedestrian? Basically, no. Though they clearly were not developed or constructed with walking in mind. In fact, expressways are generally built along secured right-of-way and are limited access facilities. In the Philippines, all expressways are tolled; meaning you have to pay to use them. Expressways are built more for long distance travel and not for the shorter ones where walking is most appropriate.

Are they car-centric? Not necessarily so because they provide a less congested alternative for long distance transport of people (buses and vans) and goods (trucks). Would you rather take the Manila North Road (McArthur Highway) to Baguio City and endure over 7 hours travel time? Or would you take the 4-hour trip via 3 expressways (NLEX, SCTEX and TPLEX)?

Are expressways supposed to reduce traffic on local roads? Yes and no. Yes, because they actually do reduce traffic at the local level when you divert long distance travel to expressways. The math tells us there is subtraction there. However, it is a no in terms of local traffic increasing over time, which should not be charged to expressways, as they are a function of other elements coming into play including population increase and economic growth. This includes a contribution to induced traffic or new trips generated by the perception of infrastructure being adequate and having the capacity to cater to more trips that are not necessarily borne by cars.

Do we need more expressways? Probably, but not in the locations or alignments like the one proposed for PAREX. Incidentally, there is another expressway being planned that seems to have escaped the attention of those against PAREX. I am talking about the Laguna Lakeshore Expressway that will be a combination of at-grade (over reclaimed land) and elevated (viaduct over the Laguna de Bai) sections leading to heart of Laguna and towards Quezon province. But that’s another story…

Article on sustainable mobility

Here is a quick share of an article from Cities Development Initiative for Asia or CDIA. The title may already be quite cliche by now (i.e., along the lines of the slogan “move people, not cars”) but the message is clear and cannot be emphasized enough especially as people grapple with the impacts of the pandemic on transportation. For the reader, take note of the avoid-shift-improve framework, which is quite useful in describing what needs to be done  in order to address the climate impacts of transportation systems.

Cities Development Initiative for Asia (April 22, 2021) “Sustainable Mobility is About Moving People, Not Vehicles,”, [Last accessed: 5/2/2021]