Abstract

Pavement distress remains a major issue on Nigerian roads, especially in rapidly urbanizing satellite towns. This study examines the impact of subgrade soil conditions on pavement failures along Arab Road in Kubwa and Idu Railway Road in Abuja. Field assessments identified rutting and potholes as predominant failures. Soil samples from depths of 0.5–1.5 m were tested for moisture content, particle size distribution, Atterberg limits, compaction, and California Bearing Ratio (CBR) according to ASTM and AASHTO standards. Arab Road soils, classified as A-6, showed moderate moisture sensitivity, an MDD of 2.03 Mg/m³, OMC of 9.6%, and a CBR of 17.35%, indicating limited support for heavy traffic. Idu Railway Road soils, classified as A-7-6, had higher moisture content, plasticity, and fines, with a CBR of 37.12%. Despite good laboratory strength, high moisture sensitivity and inadequate drainage threaten long-term stability. Overall, moisture-prone subgrades, heavy axle loads, and poor drainage are the main causes of premature pavement failures in Abuja’s satellite areas. Improved drainage and detailed geotechnical investigations are essential for durable pavement design and sustainable road performance in similar environments.

Key words: Pavement distress; Subgrade soils; Satellite town road; Geotechnical investigation; Abuja roads; Moisture sensitivity.