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Category Archives: Highway Engineering
Here is another good read especially for those who advocate or even just beginning to appreciate the concept of people-oriented transportation:
VannPashak, J. (2018) “Design for humans as they are, not as you want them to be,” http://www.medium.com, https://medium.com/@jvannpashak/design-for-humans-as-they-are-not-as-you-want-them-to-be-ef95076c0988 [Last accessed: 11/23/2018].
In a recent symposium where I made a presentation about low carbon transport and visioning and re-imagining transport, I was asked how we can re-design our transportation to be more people-oriented than car-oriented. I replied that we have to do a lot of unlearning. That is, many planners and engineers would need to unlearn many things they’ve learned in school and those they got from their workplace. One convenient excuse for not coming up with a better design, for example, is that certain planners or engineers just followed what their offices or agencies have been doing. What if what their offices and agencies (and consequently their seniors at work) where wrong all these years and what was “ginagawa na” or “nakasanayan” have led to deficient outcomes? I even joked about whether these offices or agencies were “open minded” referring to a favourite by-line by networking companies. Being open-minded in the context of having people-oriented transport solutions would be difficult if everything was “nakakahon” because these were what you learned from school and/or the workplace. It is difficult to admit that something was and is wrong.
The recent news about the groundbreaking for the C-6 expressway led some people to this site and looking for information on C-6. Here are more photos I took last month (January 2018):
The future northbound lanes of C-6 is currently under rehabilitation and are being upgraded to Portland cement Concrete Pavement (PCCP). The new southbound lanes currently serve the two-way traffic.
The sign is an old one and perhaps still in use as a barrier more than for information
You see a lot of people jogging, walking and cycling along the finished road. It shows the demand for spaces for such activities, including recreation, and a similar situation may be observed along C5 before and along the perimeter of Libingan ng mga Bayani where a lot of people do exercises and other activities along road sections that are closed to vehicular traffic.
With one lane completed the second lane is prepared for pouring of concrete. You can see the formworks along the median.
Other sections have yet to be prepared for concreting but have been stripped of the old pavement (Asphalt Concrete pavement or ACP).
What you see here at right is the compacted base/sub-base layer. The forms have not been installed yet.
Backhoe and roller at the worksite.
A grader in action.
I will post more photos later from the next time I pass by the area. From what I’ve hear so far, traffic has eased along the expanded Barkadahan Bridge but there are still bottlenecks to address along this alternative route. There will also be a need to have a higher capacity, less friction connection between C-6 and C-5 as traffic along C-6 increases and it’s become quite obvious that Taguig’s narrow streets cannot handle this increasing travel demand between the two highways. It makes sense to have a higher quality, limited access road for this purpose since Taguig roads are already congested and through traffic poses a safety hazard to the residential areas where vehicles travel through.
We did some studies a few years ago on the state of pavement engineering in the Philippines. Among the things we found was that conditions for the proper curing of concrete used for pavements of national roads are not usually met. This applied mainly for both Portland Cement Concrete Pavements (PCCP), which was the main subject of our study but also applied to Asphalt Concrete Pavements (ACP) as well as we documented practices for both types of pavements.
Last year, the traffic along Ortigas Avenue Extension was hellish for quite some time between the Rosario Bridge and Cainta Junction. One time, we eventually inched our way past De Castro, and lo and behold this scene while it was raining:
Rollers (pison) making a pass at the asphalt laid by a paving machine. Note the wet roads due to the heavy rains that afternoon.
Workers patching up the edges of the overlay as a foreman and what appears to be engineers directing them. That’s a asphalt paver in action. Note the already wet asphalt? That will have implications over the short term; often resulting in distress way ahead of the intended life of the ACP.
Dump trucks lined-up carrying aggregates for the asphalt overlay; occupying one lane of Ortigas Avenue Extension.
The queues from the westbound side stretched from Countryside to Junction. Since the intersection was already affected by the spillover, the section from Junction to Brookside was also congested.
The situation I described above is something that could have been managed other ways but would still result in severe traffic congestion as at least 2 lanes were occupied by construction (one being paved and another for staging). There were also other incomplete drainage works that exacerbated the situation. So as far as traffic management goes, I thought the contractor did the best it could given the conditions. However, I question the asphalt overlay work during heavy rains. The implications is the reduction in the intended or design life of the ACP (i.e., reduced life most likely due to the rainwater and wet conditions with the bitumen not being able to bind the aggregates as effectively as desired. And so that means the aggregates tend to loosen up more quickly resulting in the deterioration of the pavement and lead to more costly maintenance of roads.
A new bridge had been under construction beside the older Barkadahan Bridge. Instead of expanding the existing bridge, the proponents decided to build another bridge likely so as to reduce disturbance of traffic along the already congested first bridge. This is the same strategy for the bridge across the Pasig River in Nagpayong/Napindan that will reduce the potential bottleneck for when C-6’s expansion is completed. Unfortunately, the bridges don’t seem to include provisions for exclusive bicycle lanes that are clearly incorporated along much of C-6.
I took this photo as we were in queue at the approach to the intersection of Highway 2000 and the Manggagan Floodway’s East Bank Road. The new bridge can be seen here bearing eastbound traffic. The alignment at the intersection has not been addressed and so requires through traffic to basically swerve towards the entry to Highway 2000.
Here’s the intersection and the newly opened bridge. Note the vehicles coming towards my position as they follow a trajectory from the bridge to the narrow exit leg of Highway 2000.
Instead of a single lane along each direction, the two bridges now allow for at least 2 lanes of traffic either way. I say at least because a case can be made for 3 lanes to be indicated (there are no lane markings yet). The issue here though is that there is significant truck traffic crossing the bridge and two trucks traveling beside each other easily occupies the entire bridge. Thus, maybe a wide two lanes can be designated for both bridges with an opportunistic third lane forming depending on the traffic.
We conclude the month of October with the following recommended readings:
- Designing Walkable Urban Thoroughfares: A Context Sensitive Approach, An ITE Recommended Practice, 2010
- Model Design Manual for Living Streets, 2011
- Smart Transportation Guidebook, Planning and Designing Highways and Streets that Support Sustainable and Livable Communities, 2008
While these are guidelines and manuals developed and published in the United States, the principles and much of the content and context are very much applicable here.
As an additional reference, here is the latest version of functional classifications for streets that is supposed to be context-sensitive:
- Stamatiadis, N., A. Kirk, D. Hartman, J. Jasper, S. Wright, M. King, and R. Chellman. 2017. An Expanded Functional Classification System for Highways and Streets. Pre- publication draft of NCHRP Research Report 855. Transportation Research Board, Washington, D.C.
It seems late but there seems to be no really significant changes to the state of Circumferential Road 6 as the rains seem to have slowed down work on sections of the highway. We took these photos 3 weeks ago showing the nice 2-lane/2-way section on the side of the Laguna de Bay that’s been opened to general traffic. Previously, most vehicles had to use the beat-up, crater-plagued older section of what was a dike road. We were heading to SLEX via Bicutan so we were able to take a lot of photos for the entire stretch of C-6. I won’t be annotating all the photos anymore but suffice it to say that the series starts just after the Napindan Bridge in Pasig and ends prior to Taguig City’s bayside park at Lower Bicutan. Vehicles bound for C-5 or BGC via Ruhale Street should get off the newer section and negotiate a short but very bumpy road that’s not a good experience if you’re using a car. Just after the Ruhale “exit” all vehicles would have to return to the old road and have to be patient with the bad conditions of the pavement on both sides of the road.
The Transportation Science Society of the Philippines (TSSP) holds its 24th Annual Conference tomorrow, July 21, 2017. It will be held at the National Center for Transportation Studies at the University of the Philippines Diliman, Quezon City. More than a hundred participants are expected to attend this 1-day affair.
The final program for the conference may be found in the following link:
The theme for this year’s conference is “Improving Quality of Life in Urban and Rural Areas Through Inclusive Transportation.” This is also the theme for the panel discussion in the morning. The afternoon will feature four parallel technical sessions where 18 papers will be presented.
The keynote lecture will be delivered at the start of the conference by Prof. Tetsuo Yai of the Tokyo Institute of Technology, who is also the current President of the Eastern Asia Society for Transportation Studies (EASTS) under whose umbrella the TSSP is part of. TSSP is a founding member of EASTS and actually preceded EASTS by a year.
I have not used Circumferential Road 6 in a while. And so a couple of weeks ago, I was happy to see that work has resumed on the sections at Lupang Arenda in Taytay, Rizal, which is also known as Sampaguita Street. Here are some photos of the wide C-6 section. I guess there’s an opportunity here to have service roads on either side of the highway in order to manage/control local traffic. C-6, after all, is a highway and is designed for typical national highway speeds (i.e., 60 kph). The adjacent land use, however, requires slower traffic mainly due to safety concerns.
Cordoned-off section where a contractor is preparing the sub-base prior to placing the steel reinforcement and pouring concrete
Another photo of the section showing form works for the slab. Note the parked vehicles along the side on the left.
Some sections are already flooded from the heavy rains
The completed section towards Nagpayong, Pasig is a wide 4 lanes. At left is a nice view of the Laguna de Bai.
Section to Nagpayong near the boundary of Taytay, Rizal and Pasig City.
That’s a habal-habal (motorcycle taxi) terminal on the left and in front of a parked jeepney.
Two very important things about C-6 though. One concerns the Barkadahan Bridge over the Manggahan Floodway, which is too narrow for the traffic that cross it. There’s a new bridge beside it that seems to be taking too long to build. And then there’s the long stretch from Nagpayong, Pasig to Lower Bicutan, Taguig which remain in bad condition. The new section along the lakeside is already usable for Pasig-bound traffic but needs to be allowed to carry two-way traffic for the older section to be rehabilitated. C-6 is becoming a major alternative route for a lot of travelers from Rizal to and from Makati and Taguig (esp. BGC). It needs to be improved immediately as it can help decongest the Ortigas Ave. – C5 route that most Rizalenos use to go to their workplaces.
Last May, we went to a zoo in Rodriguez (formerly Montalban), Rizal. Using Waze for directions to the zoo, the app took us to a submersible bridge across the wide Marikina River from the main highway (M.H. Del Pilar) to the mainly residential area where the zoo was located. Following are photos of the submersible bridge and the newer more conventional bridge located a little further down the highway.
Submersible bridge connecting Barangay San Rafael with Barangay San Isidro
The “all-weather” bridge as seen from the submersible
There are many bridges like this submersible one across the country. Many were built as weirs or dams that could be used as bridges when the water level allowed it but could let water pass above it during wetter days. Incidentally, there’s one along a popular alternative route between Quezon City and Marikina in Tumana. That bridge can be impassable during times of heavy rains.
I frequently use Circumferential Road 5 (C-5), which is known by many names according to the MMDA, the DPWH and the LGUs it passes through. One thing I always notice is the deteriorating or deteriorated pavement, particularly along the lane designated for use by trucks. The MMDA had instituted and implements a policy requiring large trucks to use one lane of C-5 during times when the truck ban is lifted (10:00 AM to 4:00 PM). Smaller trucks are allowed to use other lanes.
The result has been a long platoon of large trucks along the designated lane of C-5 and this concentration of load on the highway has caused faster pavement deterioration for that lane. This is especially evident when the pavement surface is of asphalt concrete. Flexible as it is, the concentration of load has led to obvious pavement deformation as shown in the following photo.
For Portland cement Concrete pavement (PCCP) cases, I would presume that there is also significant damage and the distresses (e.g., cracks) can be linked to this concentration of load. This situation and the conditions for loading likely have detrimental implications on maintenance costs for C-5 and is probably an unintended consequence of the MMDA’s policy. It would be interesting to quantify the impacts of this truck lane policy, whether it has contributed to improve traffic flow along the major thoroughfare, and whether the maintenance costs have risen (and by how much) from the time the policy was implemented.