Constructing a National Transport Vulnerability Index for Nigeria: Methodology, Measurement, and Policy Applications

A systematic national transport vulnerability index would provide a rigorous evidence base for targeting transport investment, disaster preparedness resources, and social protection mechanisms toward the most transport-disadvantaged communities. This study develops, validates, and applies an original National Transport Vulnerability Index for Nigeria, contributing a methodological innovation to the transport equity and resilience measurement literature. The research proceeds through four stages: conceptual framework development grounded in capability deprivation, exposure-sensitivity-adaptive capacity resilience theory, and transport poverty literature; indicator selection through Delphi consultation with 35 transport and development experts; index construction using principal components analysis and entropy-weighting methods on data from the 2023 National Population Census, Federal Road Safety Corps records, National Bureau of Statistics household surveys, and satellite-derived road network accessibility data; and validation through convergent validity testing against community-level poverty and health outcome data. The index captures five dimensions: physical access, service availability, economic affordability, safety exposure, and climate vulnerability. Application of the index reveals that the most transport-vulnerable local government areas are concentrated in the North East and North West, with secondary clusters in rural South South communities. The index demonstrates stronger explanatory power for development outcomes than GDP per capita alone. The study provides the Nigerian government with an operational tool for evidence-based transport investment prioritisation and contributes to global methodological discourse on composite transport disadvantage measurement in data-scarce environments. Keywords: transport vulnerability index, Nigeria, methodology, transport equity, policy measurement.