Determination of the International Roughness Index Using Vehicle-Mounted Accelerometer Sensors

Pavement roughness is one of the most important functional indicators of roadway performance, playing a critical role in safety, ride comfort, and maintenance costs. This indicator is typically measured using advanced instruments such as laser profilometers, which, despite their high accuracy, are expensive, require specialized equipment, and have limited accessibility, making widespread use challenging. Therefore, developing low-cost, portable, and readily available methods for estimating the International Roughness Index (IRI) can significantly enhance pavement condition monitoring and support maintenance planning. In this study, the performance of micro-electromechanical sensors (MEMS) in the indirect estimation of IRI was evaluated. Vertical acceleration data were collected using a MEMS accelerometer installed at two locations inside a vehicle: the center console and the dashboard. The raw data were processed through noise filtering, drift removal, signal alignment, and numerical integration, and subsequently used to compute IRI values. The results showed that both sensor installation locations were capable of producing acceptable IRI estimates, with differences between the computed values and reference data from the Pavement Management System (PMS) falling within an acceptable range. The findings also indicated that sensor placement, sampling rate, and signal-processing quality are influential factors affecting the final accuracy. Overall, the results demonstrate that MEMS sensors, due to their low cost, ease of installation, portability, and ability to rapidly collect data, can serve as an efficient tool for pavement condition monitoring and support pavement management systems.