Investigation into the Relationship Between Project Size and Cost Performance in Rural Infrastructure Projects in Taraba State

The relationship between project scale and cost performance outcomes remains a significant area of interest in construction economics, particularly for rural infrastructure programmes in underserved regions. This study investigates the relationship between project size and cost performance in rural infrastructure projects in Taraba State, examining road, water, and small building projects funded under state and federal rural development programmes between 2020 and 2024. A quantitative design was used, with project cost and completion records from 60 projects analysed alongside survey responses from 76 quantity surveyors and project officers. Data were analysed using regression analysis and descriptive statistics. Findings reveal a non-linear relationship between project size and cost overrun, with very small projects (under N20 million) and very large projects (over N500 million) showing the highest cost deviation rates relative to original estimates. Very small projects suffer from under-investment in pre-contract planning, while large projects are more susceptible to scope creep and coordination failures. Medium-sized projects demonstrate the best cost performance. The study recommends differentiated contract management protocols based on project scale, with enhanced planning requirements for very small rural projects and structured cost control checkpoints for large ones. Quantity surveyors are urged to develop rural project cost benchmarks specific to Taraba State. This research enriches the rural infrastructure cost management literature for the North East geopolitical zone. Keywords: project size, cost performance, rural infrastructure, Taraba State, construction economics