Low cost ultrasonic roughometer for pavement roughness measurement

Along with the development and construction of new roads, a significant percentage of the existing road network also need reconstruction and renovation to sustain the momentum of the economic growth of any developing country like India. Role of state agencies involved in road maintenance, assessment and monitoring of pavement conditions is of utmost importance for maintaining good quality pavement often assessed by riding comfort signified by pavement roughness. A large number of devices have been developed around the world for roughness measurement. With significant developments of costly automated and high-output road survey equipment in the recent past for road network condition monitoring, it is possible now to conduct a survey at normal traffic flow speed, may not be a feasible option for state agencies of developing/underdeveloped countries. In this work, a new low-cost Ultrasonic Roughometer (Us-R) device is developed for the measurement of pavement roughness. Us-R has the added benefit of acquiring precise roughness data along the wheel path with ease of operating without hampering the normal traffic flow. MERLIN is used to calibrate the new device's measuring capacities fitted in a bi-cycle and motorcycle. The IRI value collected by fitting Us-R device in both bi-cycle and motorcycle differs within 5%, producing a high correlation. The roughness values collected using the Us-R are also consistent with time. The easy fixing of Us-R device with a readily available vehicle like bi-cycle/motorcycle makes it user-friendly and a good option for evaluating road roughness in underdeveloped and developing countries. The newly developed low-cost device can be used advantageously over existing devices present in the market for roughness measurement by state agencies involved in road maintenance of developing country like India.