Measurement of road condition in terms of its surface roughness is an important parameter. Assessment of longitudinal profile quality of road surfaces is a commonly considered primary requirement of any newly constructed roads and also in service pavements. Internationally, the riding quality is related to unevenness of pavement surface and quantified in terms of roughness, and is expressed as International Roughness Index (IRI).

There are several low cost, traditional instruments used for measuring roughness of pavements such as Straight Edge, Wedge scale etc. However with the advancement of technology, different sophisticated equipments have emerged, which gives accurate values of unevenness or IRI (Kumar, 2014).

In this study, a low cost device, MERLIN has been fabricated to measure road roughness. Evaluation of roughness of two selected pavements has been made with the fabricated MERLIN and also Reduced Level (RL) values are determined along the same road stretches by using Total Station. Statistical analysis has been carried out on the data collected and regression equations were developed between these two parameters. A comparison between the results of MERLIN and Total Station is made, and suitability of MERLIN as a low cost equipment is investigated with reference to routine evaluation of pavements on short stretches.