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Traffic schemes in Metro Manila

I interrupt my writing on the U-turn Scheme to write about other schemes first and particularly about vehicle restraint measures that have been implemented in Metro Manila (and probably elsewhere in the country).

I was researching on papers that we could attach to our letter to the mayor of Quezon City prior to his attending a Metro Manila Council (MMC) meeting where the mayors of the 15 local government units comprising Metropolitan Manila would be discussing the proposed implementation of an Odd-Even Scheme along EDSA. The proposal would be presented by the Chair of the Metro Manila Development Authority (MMDA) for decision of the MMC. Earlier, the MMDA Chair gave interviews to the media and mentioned a study made by the NCTS pertaining to congestion along what is regarded as the busiest thoroughfare in Metro Manila and perhaps the entire country. The MMDA Chair did not say the title of the study nor were there specifics on the authors of the study. And so it piqued my interest enough to search for the paper that the MMDA Chair used in his statement. The search led to two papers I co-authored with two very good friends. The material I was able to dig up had enough for several blogs but rather than re-invent the wheel, I will just reproduce what has already been written, reviewed, published and presented back in 2006 and 2007. Since the following text will a verbatim reproduction of parts of the paper, I have italicized the material and cite the paper from where it came from.

“Traffic management refers to a wide range of measures and programs designed to improve traffic flow and enhance traffic environment without substantial capital investment that may include ROW acquisition. Traffic management is necessary due to the significant imbalance between demand and supply in traffic that results in chronic congestion and its derivatives – environmental degradation and decline in traffic safety.

Measures formulated to address Metro Manila’s traffic problems are based on established, conventional travel demand management (TDM) and transport systems management (TSM) schemes. However, the schemes have been adapted to local conditions and are still being modified to better address the requirements of Metro Manila travelers. The MMUTIS Technical Report No. 8 (1999) presents a comprehensive review of traffic management schemes implemented in Metro Manila from the 1970’s to the present. Among the schemes formulated and applied in various forms and extent are the following:

• Traffic signal control system (TEAM, SCATS)

• Flow management schemes (one-way systems, reversible lanes),

• Toll discounts (for the North and South Luzon Expressways),

• Bus management schemes (bus segregation, provincial bus restrictions, designated bus lanes), and

• Pedestrian-focused programs (overpasses, underpasses, discipline zones)

The UVVRP and the Truck Ban are TDM measures that have evolved since their introduction in 1995 and 1980, respectively. The U-turn Scheme is a TSM solution introduced in 2003 that was intended to promote uninterrupted flow in Metro Manila by reducing delay incurred at intersections (i.e., through intersection closure).”



Regidor, J.R.F. and Tiglao, N.C.C. (2007) “Alternative Solutions to Traffic Problems: Metro Manila in Retrospect,” Proceedings of the 11th World Conference on Transport Research (WCTR 2007), 24-28 June 2007, University of California Transportation Center, University of California, Berkeley, CA, USA, DVD.


Full circle with the U-turns: Traffic Signals in Metro Manila

Since last week, it seemed as if a ghost of Christmas past has come to haunt me and my colleagues at the NCTS. We had some unexpected visitors from the Traffic Engineering and Management (TEAM) group of the Department of Public Works and Highways (DPWH). They were at the Center to consult about a project being formulated by the group together with the MMDA for new traffic signals for Metro Manila. DPWH-TEAM has a long history with NCTS starting when that unit was created when the Philippines invested on its first coordinated traffic signals in the 1970s.

At that time, the NCTS was still the Transport Training Center (TTC), and was the site of the first traffic control center for signals that were installed along Quezon Avenue. The package was funded by a loan from the Japanese government and hence involved traffic signals manufactured by Mitsubishi. Years and many TEAM project phases later, most of Metro Manila’s major intersections would be signalized and traffic signal control would be under the Traffic Engineering Center, which until 2003, was under the DPWH. In the 1990’s, the TEC and TEAM worked together to acquire the Sydney Coordinated Adaptive Traffic System (SCATS), which at the time was already installed and running in most major intersections in Cebu City.

SCATS was supposed to usher in a new era in traffic control in Metro Manila until some major problems eventually plagued its operation. One of these problems was power. However, this was something everybody else was concerned with because of the power crisis of the early 1990s. It was also something that seemed to be easily solvable with the acquisition and installation of uninterrupted power systems (UPS) and generators that allowed the facility to operate even during blackouts.

Another technical problem cropped up just about the same time when the TEC and TEAM people were trying to solve the power issue. This time, it was something much more complicated and perhaps, what led to the system losing its credibility in Metro Manila and a chain reaction of sorts in as far as reactions go. The communications problem was a critical one and rendered the system practically unreliable for what it was supposed to solve – congestion. SCATS required a reliable network for its controllers and computers to communicate with each other. This communication allowed its software to assess network-wide traffic demand measured by means of detectors embedded in the pavement at each approach lane of an intersection. Data from these detectors are transmitted to computers in the control center, which then compute for  the optimum cycle times for each signalized intersection. The computers determine which intersections need to be coordinated and how (i.e., alternating or simultaneous), and this process allows SCATS to adapt to variations in traffic. Hence, its name which seemed only appropriate given its performance in what is now the expanded network in metropolitan Cebu.

The failure of SCATS in Metro Manila was further hastened by traffic enforcers who were only too eager to intervene. This intervention was more of interference as enforcers started switching the traffic signal controllers to manual mode at the slightest indication that the signals would appear to be non-responsive to changes in the traffic situation. In truth, it takes a few minutes for the detectors to collect data and send it to the computers that will compute for the appropriate cycles and signal settings as well as determine which intersections to “marry” and “divorce” – to borrow terms used by traffic engineers in Cebu City for the process of coordinating intersections throughout the day. Due to this rampant practice by enforcers in Metro Manila, it was only a matter of time before SCATS was declared a failure and claims were made that Metro Manila traffic is so much more complicated than Cebu’s, where SCATS was a success (it still is today).