Evaluation of Road Damage Level Using Surface Distress Index (SDI) – Case Study

Abstract Traffic and environmental effects require regular pavement maintenance, which must be guided by accurate condition data to ensure timely and effective repairs. Road rehabilitation must be given top priority because maintaining, renewing, repairing, and reconstructing road infrastructure is an expensive operation, and the funds allocated for such work are sometimes limited. This study evaluates the pavement conditions of a road in Diwaniya City, Iraq, using the Surface Distress Index (SDI) approach, which is based on crack area, crack breadth, potholes, and rutting depth. The findings revealed that 36% of the chosen roads (9 segments) are in poor condition, resulting from potholes and rutting damage. Additionally, according to the resulting total SDI values, 8 segment parts (or 32% of the chosen road) are in unacceptable condition, while only 8 segment parts have fair damage. To support decision-making, the study suggests routine road assessments using tools like visual inspections, drones, or sensors, along with preventive maintenance methods such as chip sealing, resurfacing, and crack sealing to extend road life and reduce major repairs. High-traffic and safety-critical sections should be prioritized to make the most of the limited budget. Cost-effective repair techniques, including full-depth reclamation for severe damage and cold patching for temporary fixes, should be used. By suggesting repair techniques like full-depth patching, slurry seal, or overlay based on segment-level damage, this study assists policymakers in settings with limited resources in making well-informed decisions.