Road roughness is a very important indicator of road quality. Roads with rough surfaces negatively impact riding quality, increase vehicle operating cost, increase potential for accident and reduce pavement life.

The International Roughness Index (IRI) is a standard that is used by road professionals worldwide to quantify road surface roughness. The Department of Public Works and Highways through DO No. 47 series of 2015, has adopted the IRI as a way to measure the roughness of national primary roads:

“Presently, road roughness is quantified in terms of International Roughness Index (IRI) which was developed by the World Bank in the 1980s. Henceforth, the following values of IRI shall form part of the basis for acceptance of newly constructed concrete and asphalt road projects.”

The DPWH has set the acceptable international roughness index (IRI) value for asphalt and concrete pavements of national primary roads to not more than 3.00 m/km.

Our mission is not only to construct road networks that will last. We must also ensure that we build roads that provide safe and enjoyable riding experience for all end users. One project: the Plaridel Bypass Road Project Phase 1 is an excellent case-in-point.

The Plaridel Bypass Road Project Phase 1 is an infrastructure project with the Philippine government which was completed in 2011. About three years after project completion, the Department of Public Works and Highways performed an IRI survey on February 14, 2014 to measure and analyze the quality of pavement surface of the Plaridel Bypass Road Phase 1 based on IRI parameters.

For this project to pass the inspection, IRI values collected by a calibrated device must not exceed 3.00.

The Pavement Smoothness Report published by the DPWH indicate that the survey of Plaridel Bypass Road Project generated IRI values of between 2.062 to 2.084. These IRI results validate that the pavement surface along Plaridel Bypass Road has remained acceptably smooth even after three years of road use.

The measured average roughness in this project is also one of the lowest among national primary roads, making it a benchmark in high-quality road construction.

But more than the pride in this accomplishment, the IRI survey results of Plaridel Bypass Road serve as a constant reminder for us to consistently build quality roads for the public and for future generations.


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