GIS-Based Spatial Assessment and Maintenance Prioritisation of Highway Pavements Using Field-Derived Distress Data: A Case Study of Delta State, Nigeria

Highway pavements in Delta State deteriorate steadily under heavy commercial and petroleum-sector traffic, poor roadside drainage, and inconsistent maintenance funding, yet decisions on which sections to repair first are still made in the state largely without reference to spatial condition data. This study set out to address that gap through two objectives: to assess the field-derived pavement distress condition of selected highway sections in the state using the Pavement Condition Index (PCI) method and to develop a Geographic Information System (GIS)-based spatial framework for prioritizing maintenance interventions from the resulting data. Eighteen road segments across five corridors, Asaba, Warri-Ughelli, Oghara, Sapele, and the Ughelli link, were surveyed. Distress type, severity, and extent were recorded through a visual field survey following ASTM D6433 procedures, with distress locations logged by handheld GPS for import into a segment-level GIS database built in ArcGIS Pro. PCI values were computed from standard deduct value curves and classified into six condition bands. Scores ranged from 25 to 72 across the eighteen segments, with a network mean of 49.4, and eight segments fell into the poor or fair condition bands. Spatial mapping placed the most deteriorated sections along the Warri-Ughelli axis and at the Ughelli link, where poor-condition segments clustered rather than scattering evenly across the network. A composite Maintenance Priority Index, combining PCI with distress severity and traffic exposure weighting, produced a ranked list identifying three segments, UG-02, WU-01 and AS-04, as the highest priority for intervention. The study concludes that pairing field-derived PCI data with GIS mapping gives Delta State road authorities a defensible, spatially referenced basis for allocating maintenance resources and recommends that the state adopt the resulting priority ranking as a starting reference for its next maintenance budget cycle.