Permanent Rectification of Road Accident Blackspots: Engineering Investigation, Diagnosis, and Safety Improvement Measures

Road accident blackspots are locations where crashes repeatedly occur due to the combined influence of roadway geometry, traffic operations, pavement condition, visibility, roadside environment, and road user behavior. The present paper develops a journal-style research framework for the permanent rectification of accident blackspots using systematic civil engineering investigation and highway safety analysis. The study integrates historical accident data, field reconnaissance, road inventory surveys, traffic volume studies, spot speed analysis, pavement condition assessment, visibility evaluation, and road safety audit procedures to diagnose recurring crash causes. Selected blackspot categories were examined through accident frequency, severity, traffic conflict patterns, geometric deficiencies, pavement defects, drainage problems, inadequate traffic control devices, and vulnerable road-user exposure. The analysis indicates that blackspot crashes are rarely caused by a single factor; rather, they arise from interacting deficiencies such as restricted sight distance, excessive operating speed, narrow carriageways, weak shoulders, poor drainage, faded markings, inadequate lighting, unsafe intersections, and roadside hazards. Permanent countermeasures are therefore proposed as a package of engineering interventions, including carriageway and shoulder widening, geometric correction, pavement strengthening, improved drainage, retro-reflective signs, thermoplastic markings, crash barriers, speed-calming measures, intersection channelization, pedestrian facilities, and post-implementation monitoring. The paper concludes that a data-driven and standards-based approach, aligned with IRC and MoRTH requirements, can substantially improve road safety, reduce accident severity, enhance traffic flow, lower vehicle operating costs, and support sustainable highway infrastructure management.