Quantification of effect of manholes on pavement smoothness

Pavement roughness is a key factor in determining highway user satisfaction. Manholes on the highway surface are one of primary factors affecting the pavement smoothness. This paper is to quantify the effect of manholes on pavement smoothness. A 2-km road segment on a recently constructed highway was chosen to measure pavement smoothness using a Hi-Lo detector and an inertial profiler. Data collected over a five-year period of time were analyzed to develop the smoothness prediction model and to evaluate pavement distress around manholes. A growth function was developed to explain the change of pavement smoothness. The deterioration value (DV) was applied to perform the life-cycle cost analysis, and to estimate the maintenance cost according to premature pavement failures that might result from manholes. The existence of manholes was shown to shorten the pavement service life with an increasing DV. Furthermore, a life-cycle-cost analysis (LCCA) was conducted to take into account the effect of pavement distance on the maintenance cost. According to LCCA, a surcharge fee was proposed to compensate the increase in the maintenance budge due to the pavement failure related to manholes.