Abstract Premature technical issues in roads and highways worldwide often stem from inadequate asphalt concrete composition or intense traffic loads under varying climatic conditions. This study evaluated the performance of both original and low-density polyethylene (LDPE)-modified asphalt concrete under various thermal cycling conditions. Three thermal cycling ranges [-20°C to +20°C, +20°C to +40°C, and +40°C to +60°C] were applied to assess the mixtures’ mechanical performance. The LDPE modification involved replacing 5% of the bitumen weight with dry plastic bags. Performance was assessed using Marshall stability, dynamic creep, wheel tracking, and resilient modulus tests. Results indicated that LDPE modification significantly improved Marshall stability, reduced permanent deformation, and increased the stiffness modulus of the asphalt concrete. Notably, freezing-thawing cycles [-20°C to +20°C] caused more damage to the asphalt concrete compared to heating-cooling cycles. Moreover, the LDPE-modified mixture demonstrated enhanced performance across all thermal cycling ranges, suggesting its potential to improve road durability under diverse climatic conditions.