Effectiveness of microsurfacing treatments

This paper determines that microsurfacing can offer average reductions of 0.442 international roughness index (IRI) [in m/km], 4 mm in rut depth, and an increase of 6.2 pavement condition rating (PCR) units. The pretreatment pavement condition was determined to be an influential factor of the treatment effectiveness in the short-term. The long-term analysis showed that for each measure of effectiveness (MOE) and performance indicator, effectiveness is influenced by freeze index, traffic, and pavement class: effectiveness, in terms of service life, was found to range from 2 to 10 (average 5) years for IRI; over 10 years for rutting; and 4 - 15 years (average 7) for PCR; in terms of increased-pavement-condition, effectiveness is 7-27% IRI decrease, 90-96% rut reduction, and 2-7% PCR increase; in terms of both MOEs, effectiveness is 0.474-4.074 (m/km) years, 16-104 mm years, and 18-56 PCR years. Greater long-term effectiveness was found to be generally associated with lower freeze and traffic conditions, and lower pavement class. The study affirms that microsurfacing can effectively address rutting, increase ride quality, and has a significant service life.