Drivers’ safety from the perspective of integrated triangular assessment of human, environmental, and vehicle factors on Nepal’s major highways

Abstract

Introduction: Drivers’ safety remains a critical concern within the context of Nepal’s major highway network, threatened by a triangular interaction of human, environmental, and vehicle-related factors. Despite alignment with global safety initiatives, Nepal records a disproportionately high fatality rate of 15.9 per 100,000 population, significantly exceeding the South Asian regional average. This crisis impacts young, economically active drivers, while risks are further intensified by rapid motorization, poor infrastructure, and weak vehicle inspection systems. This study aimed to assess the multidimensional determinants affecting driver safety across Nepal’s highways. Methods: Mixed-methods approach evaluated these determinants by integrating secondary crash data (2016–2025) from Nepal Police with road infrastructure audits. Field assessments examined geometry, pavement conditions, and signage, while 155 structured surveys and stakeholder interviews (including police and residents) provided qualitative insights into behavioral challenges. Spatial analysis using Kernel Density Estimation and Moran’s I was utilized to scientifically identify high-risk crash hotspots. Results: Results indicate driver risk is amplified by human factors (over-speeding, fatigue, alcohol use, inexperience), environmental hazards (inadequate lighting, poor geometry, monsoon-induced landslides), and vehicle defects (overloading, brake failures). Corridor-level analysis highlights Banepa and Chisapani as critical risk zones, while the Prithvi Highway exhibits dispersed crash patterns linked to fatigue and weak barriers. Conclusion: Driver safety in Nepal is defined by the interplay between human behavior, infrastructure flaws, and vehicle condition. Key measures must include strengthening governance, upgrading road and vehicle standards, and tackling fatigue through a comprehensive, well-enforced strategy.