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

Abstract

Introduction: Drivers’ safety is a critical concern of road safety particularly in the context of Nepal’s major highways. This has threatened by a triangular interaction of human (driver), environmental and vehicle-related factors. Despite regulatory frameworks and alignment with global initiatives, Nepal records disproportionately high fatality rates of 15.9 per 100,000 population, above the South Asia regional average. Young and economically active drivers are particularly vulnerable, while poor infrastructure, rapid motorization, and weak vehicle inspection systems intensify risks. In light of above facts, this study is aimed to assess the multidimensional determinants affecting safety of the drivers across Nepal’s major highways, in prospect to human, environmental and vehicle-related factors.

Methods: A mixed-methods approach was applied to assess determinants of drivers’ safety. Secondary crash data from Nepal Police (2016–2025) were combined with road infrastructure audits and surveys. Field assessments examined road geometry, pavement conditions, and signage, while 155 structured surveys and key stakeholder interviews (traffic police, policy maker, implementer, and residents) provided insights into driver behaviour and challenges. Spatial analysis using Kernel Density Estimation and Moran’s I identified high-risk crash hotspots.

Results: Findings reveal that over-speeding, fatigue, alcohol use, and limited driving experience significantly increase the risks to crash and driver. Environmental factor includes, poor road geometry, degraded pavement, inadequate lighting, and monsoon-induced landslides further compromise safety. Vehicle-related factors such as overloading, brake failures, and poor maintenance undermine drivers’ control. Corridor-level analysis highlights Banepa (Araniko Highway) and Chisapani (East–West Highway) as critical risk zones, while the Prithvi Highway shows dispersed crash patterns linked to fatigue and weak barriers.

Conclusion: Driver safety on Nepal’s highways is the interplay of human (driver) health and behaviour, infrastructure flaws, and vehicle condition. It requires tailored interventions based on specific corridor patterns. Key measures include strengthening governance, upgrading road and vehicle standards and tackling issues like fatigue and risky driving. A comprehensive, well-enforced strategy is essential to prevent crashes and improve safety performance.