The results are presented from a 2-year study on the impact of utility trenching on urban flexible road network pavement roughness, pavement surface distress, structural carrying capacity, pavement life cycle, rehabilitation and maintenance requirements, and the costs associated with these impacts in Ottawa-Carleton, Canada. Included are the pavement performance and life-cycle relationships developed using modified methodologies to address concerns raised by reviews carried out by Construction Technology Laboratories Inc. and the National Research Council of Canada on utility trenching studies to date. In this study, normalized individual pavement section life cycle, a composite pavement quality indicator, and performance prediction models calibrated with numerous years of field data were used in the life-cycle and pavement performance determination. These modifications made to the conventional pavement management system when used to determine the impact of utility trenching are shown to provide performance and life-cycle relationships with better correlation than algorithms used in the previous studies. In this study, very high coefficients of determination (R-squared) of 0.79 to 0.85 were obtained for the pavement performance and life-cycle relationships regressed from field data for quantification of urban road network pavement with and without the impact of utility trenching. The factors and costs associated with the impact of utility trenching, such as reduction in pavement life cycle, additional cost for subgrade base repair, pavement strengthening requirements from loss of fatigue structural carrying capacity, and the additional area affected beyond the trenched area, are also quantified in this study.