Empirical Analysis of Factors Influencing Construction Delay in Public Infrastructure Projects Across Nigeria’s Six Geopolitical Zones

Construction project delays impose significant economic costs on Nigeria's infrastructure programme, yet a comprehensive empirical analysis covering all six geopolitical zones and differentiating delay drivers by zone and sector is absent from existing literature. This study empirically analyses the factors influencing construction delays in public infrastructure projects across all six Nigerian geopolitical zones. A mixed-methods research design was adopted, with structured questionnaires administered to 180 construction professionals (contractors, consultants, and government client representatives) from 60 completed or ongoing public infrastructure projects, ten per zone. Factor rankings were analysed using the Relative Importance Index, and cross-zone comparison was conducted using Kruskal-Wallis tests. Multiple regression analysis identified statistically significant predictors of project schedule variance. Results indicate that inadequate funding and payment delays are the highest-ranked delay factor across all zones (RII = 0.89). Contractor financial difficulties rank second nationally (RII = 0.86). Zone-specific factors include security constraints as the highest additional delay factor in the North East (RII = 0.91 within zone), and community land disputes as distinctive to the South South zone (RII = 0.78). The regression model explains 71 percent of schedule variance. The study fills an important evidence gap by providing geographically stratified delay factor analysis. It recommends zone-differentiated project planning protocols and mandatory project performance bond requirements for government contracts above 200 million naira.

Keywords: construction delays, public infrastructure, geopolitical zones, Nigeria, relative importance index