INVESTIGATING THE CAUSES OF FREQUENT FAILURES IN FLEXIBLE PAVEMENTS ON HIGHWAYS IN BANGLADESH: A CASE STUDY OF THE DHAKA–SYLHET CORRIDOR

—Bangladesh’s highway network is predominantly composed of flexible pavements, yet their durability is frequently undermined by premature failures driven by heavy axle loading and harsh climatic conditions. This research focuses on recurrent pavement distress along the Dhaka–Sylhet Highway (N2), a critical corridor for both domestic transportation and international trade. A mixedmethods approach was employed, combining field surveys, photographic evidence, and stakeholder consultations. Visual assessments of a 40 km segment identified widespread surface and structural defects, including rutting, alligator cracking, potholes, corrugation, bleeding, raveling, and localized depressions. Feedback from engineers, contractors, consultants, and road users highlighted dissatisfaction with existing maintenance practices, particularly deficiencies in drainage management and patch repairs. Analytical findings suggest that the principal causes of deterioration are axle overloading, inadequate drainage infrastructure, poorquality construction materials, insufficient site supervision, and reliance on reactive rather than preventive maintenance. To address these challenges, the study recommends enforcing axle load regulations, modernizing drainage systems, implementing proactive maintenance programs, strengthening construction quality assurance, and adopting digital asset monitoring tools. Overall, the results emphasize the necessity of shifting toward a sustainable and data-driven pavement management system to enhance highway performance, safety, and long-term cost efficiency in Bangladesh.