Structural Assessment of Pedestrian Footbridges in Kaduna State: Safety and Design Compliance

Pedestrian footbridges serve a critical mobility function in urban and peri-urban areas of Nigeria, yet their structural safety is often inadequately evaluated over their service life. This study conducts a structural assessment of twelve pedestrian footbridges across Kaduna Metropolis and selected rural areas in Kaduna State within the North West geopolitical zone, examining compliance with the provisions of BS 5400 and the Federal Ministry of Works Bridge Design Manual. The assessment methodology incorporated visual inspection, load testing using equivalent pedestrian crowd loading, vibration frequency measurement, and photographic documentation of structural defects. Geometric surveys were conducted to detect excessive camber or sag indicative of long-term deformation. Results indicate that eight of the twelve bridges displayed structural deficiencies including section loss due to corrosion in steel hangers, longitudinal cracking in concrete deck slabs, and inadequate parapet height below the 1.1-metre minimum standard. Vibration response testing identified two bridges with fundamental natural frequencies below 2 Hz, raising concerns about resonance under synchronised pedestrian loading. The overall structural condition rating of seven bridges was classified as poor or critical using the Nigeria Infrastructure Assessment Rating system. The study calls for urgent rehabilitation of the three most severely deteriorated structures, adoption of a standardised inspection protocol for all pedestrian bridges in the state, and integration of footbridge safety into State Ministry of Works infrastructure management frameworks. Keywords: pedestrian footbridges, structural assessment, Kaduna State, corrosion, vibration.