Caught (up) in traffic

Home » Posts tagged 'Highway Engineering'

Tag Archives: Highway Engineering

On asphalt overlays and opportunities to rationalize pavement markings

Entire road sections along my commuting routes have had recent asphalt overlays or are being prepared for it. This is part of the national government’s regular maintenance program for roads implemented by the Department of Public Works and Highways (DPWH).

Newly asphalted pavement along the eastbound section of Ortigas Avenue Extension – can you guess how many lanes will fit here?

The previous photo was taken one week ago. This is what the section looks like after the contractor restored the pavement markings. I say restore because these are practically the same 3 lanes prior to the asphalt overlay to the rigid pavement structure.

Pavement marking delineating the traffic lanes, median and gutter

I wonder if the DPWH included bike lanes when they contacted the asphalt overlay and pavement markings for this road. There was none before and the new overlay presented a blank slate to which Class III bike lanes could at least have been provided. There is already an increasing number of bike-to-work traffic along Ortigas Ave. Ext. and the Manila East Road, which connects the large towns of Rizal and serves as one of the major arterials connecting the Province of Rizal to Metro Manila (the other being Marcos Highway).

Asphalt overlays like this provide opportunities to rationalize road space through adjustments to the pavement markings. Granted that there’s significant bus and truck traffic along this road, it is still possible to allocate or at least delineate 1.5m to 2m for cyclists. That should also help in making motorists aware of bike traffic and in the long run influence behavior towards safer travels for all road users.

On an ‘induced demand calculator’

Induced demand or traffic is a popular topic these days thanks to the proposal of a private company to build an elevated tollway along the Pasig River. The topic is also much in circulation the past few years as the DPWH’s part in the government’s Build, Build, Build program has road widening as a major component. There are many completed, ongoing and planned projects across the country that involves road widening, particularly increasing the number of lanes of typical national roads from 2 to 4, not counting the shoulders (paved or unpaved). The results are mixed as there are roads that definitely required capacity increase in the form of additional lanes, and there were roads that did not require them. The latter were still expanded and perhaps the agency did so because their key performance indicators basically obliged them to undertake such projects regardless of the need. Somehow, these were justified and yet there were and are many questionable road widening projects especially those that involved the cutting of decades if not century old trees (e.g., the Kamatchile and Acacia trees that used to line up long sections of national roads in Tarlac are no more) or the demolition of heritage structures such as houses.

A came upon this article about an “Induced Demand Calculator” developed in the US. I have not gone through the calculator itself but such a tool could be quite useful in quantifying the impacts of road widening while pushing for other options to improve transportation and traffic that is not the typical “solving traffic” type of approach. Here is the article in Streets Blog:

I am not aware if there are similar tools being developed here. Such a calculator will require data from various sectors including construction costs, operations and maintenance costs, value of time and current and projected vehicular and person trips that can be translated into traffic volumes.