This study identified high-risk locations (hotspots) using geographic information systems (GIS) and spatial analysis. Five years of accident data (2013–2017) for the Lokoja-Abuja-Kaduna highway in Nigeria were used. The accident concentration analysis was conducted using the mean center analysis and Kernel density estimation method. These locations were further verified using Moran’s I statistics (spatial autocorrelation) to determine their clustering with statistical significance. Fishnet polygon and network spatial weight matrix approaches of the Getis–Ord Gi* statistic were used in the hotspot analysis. Hotspots exist for 2013, 2014, and 2017 with a significance level between 95–99%. However, hotspots for 2015 and 2016 have a low significance level and the pattern is random. The spatial autocorrelation analysis of the overall accident locations and the Moran’s I statistic showed that the distribution of the accidents on the study route is random. Thus, preventive measures for hotspot locations should be based on a yearly hotspot analysis. The average daily traffic values of 31,270 and 16,303 were obtained for the northbound and southbound directions of the Abaji–Abuja section. The results show that hotspot locations with high confidence levels are at points where there are geometric features.

This study identified high-risk locations (hotspots), using geographic information systems (GIS) and spatial analysis. Five years of accident data (2013-2017) for the Lokoja-Abuja-Kaduna highway in Nigeria were used. Accident concentration analysis was carried out using the mean center analysis and Kernel density estimation method. These locations were further verified using Moran’s I Statistics (Spatial Autocorrelation) to determine their clustering with statistical significance. Fishnet polygon and Network spatial weight matrix approaches of Getis-Ord Gi* statistic for hotspot analysis were used for the hotspot analysis. Hotspots exist for 2013, 2014, and 2017 with a significance level between 95% - 99%. However, no hotspots exist for 2014 and 2015 since the pattern is random. The spatial autocorrelation analysis of the overall accident locations with a z-score = 0.0575, p-value = 0.9542, and Moran's I statistic = -0.0089 showed that the distribution of accidents on the study route is random. Thus, preventive measures for hotspot locations should be based on a yearly hotspot analysis. The average daily traffic values of 31,270 and 16,303 were obtained for the Northbound and Southbound directions of the Abaji-Abuja section. The results show that hotspot locations with high confidence levels are at points where there are geometric features.

Lagoon environments exposed concrete structures to sulphate and chloride-rich conditions that sped up deterioration and put traditional service-life prediction techniques to the test. The degrading behaviour of C30 concrete with crystalline and hydrophobic admixtures was measured in this study under controlled exposure to saline lagoon water, which are typical of coastal developed settings. To enhance long-term durability forecasting, a dual-phase degradation modelling framework was created that combined environmental deterioration kinetics with mechanical performance indicators. Both Power Law and Logarithmic growth models were used to evaluate phase I maturity; they showed consistent hydration in freshwater but a sharp decline in correlation when exposed to lagoon water After a 90-day kinetic tipping point, where traditional growth-based models overestimated residual capacity by up to 120%, Phase II used an exponential decay formulation to describe actual long-term deterioration trends. According to results from a 220-day exposure study, split tensile strength offered more sensitivity to interfacial transition zone (ITZ) deterioration, while compressive strength concealed early-stage microstructural damage. Over the anticipated service life, the crystalline-modified mix (C+AQ) maintained a higher Relative Durability Index (RDI) and decreased the degradation rate constant by 87.2% in comparison to the control. Densification of the ITZ and decreased ionic intrusion in the improved system were confirmed by microstructural investigation. These results showed that tensile-centric, dual-phase modelling, which included both exponential decay-based long-term prediction and Power Law hydration assessment, offered a strong framework for evaluating durability and designing ecologically friendly coastal concrete infrastructure.