Validation of a Low-Cost Pavement Monitoring Inertial-Based System for Urban Road Networks

Road networks are monitored to evaluate their decay level and the performances regarding ride comfort, vehicle rolling noise, fuel consumption, etc. In this study, a novel inertial sensor-based system is proposed using a low-cost inertial measurement unit (IMU) and a global positioning system (GPS) module, which are connected to a Raspberry Pi Zero W board and embedded inside a vehicle to indirectly monitor the road condition. To assess the level of pavement decay, the comfort index a_wz defined by the ISO 2631 standard was used. Considering 21 km of roads with different levels of pavement decay, validation measurements were performed using the novel sensor, a high performance inertial based navigation sensor, and a road surface profiler. Therefore, comparisons between a_wz determined with accelerations measured on the two different inertial sensors are made; in addition, also correlations between a_wz, and typical pavement indicators such as international roughness index, and ride number were also performed. The results showed very good correlations between the a_wz values calculated with the two inertial devices (R² = 0.98). In addition, the correlations between a_wz values and the typical pavement indices showed promising results (R² = 0.83-0.90). The proposed sensor may be assumed as a reliable and easy-to-install method to assess the pavement conditions in urban road networks, since the use of traditional systems is difficult and/or expensive.