I’ve written about Circumferential Road 6 many times in the blog. Mostly, these were about the existing sections along the Laguna de Bai in  Taguig and Pasig cities of Metro Manila and Taytay in Rizal Province. I share below two maps showing different alignments of C-6. The first one is a rather old one from the 1990s that I recall was from a presentation of a friend at DPWH.

An old map I got from the DPWH a long time ago that I have used in my lectures.

The second map is supposed to be more recent, perhaps in the last 5 to 10 years if not more recent. This shows a more realistic alignment composed of what looks like existing road sections that were connected to form a semblance of a circumferential alignment.

Here is a more recent map that’s also attributed to the DPWH.

In the first map, you will notice that the proposed alignment is more circular and smoother. This means that the road would have had a mostly new alignment instead of utilizing existing roads like Circumferential Road 5 before it. The newer sections for the latter were the ones connecting the existing roads. For the second map, noticeable is the somewhat forced connections of what looks like existing roads on the map. And while for Map 1 the alignment will be passing under the La Mesa reservoir, the alignment for Map 2 will circle the watershed like a coastal road. The alternative alignments presented an interesting exercise for students of highway engineering particularly for the topic of alignment design. Do you pick an entirely new alignment, sketch it out and determine the crossings and other constraints or do you try to make do of what roads are existing and perhaps improve (i.e., widen) these to produce an arterial?

The proposed alignment for what is now called the Southeast Metro Manila Expressway (SEMME) seems closer to the alignment in Map 1 than the one in Map 2. I will write about the proposed expressway that was recently launched in the next post.

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