Key driving factors of cost overrun in highway infrastructure projects in Nigeria: A context-based perspective

Extensive research towards identifying the attributable cost overrun factors globally has been conducted predominantly from a survey-oriented perspective, which disregard the contextual basis on which these triggers manifest. This study aims to explore the driving factors of cost overrun in highway projects, specific to the Nigerian context. The research used a context-based approach to seek project stakeholders' perspectives on the key drivers of cost overrun in highway projects in Nigerian. Semi-structured interviews were conducted with client, contractor and consultant organisations involved in the provision of highway infrastructure projects in Nigeria. The collected data was analysed using a developed coding framework grounded on a case study approach, principles of inductive thematic analysis and saliency analysis to identify the key drivers. Findings from the analysis identified triggers from macroeconomic, societal, leadership and project management perspectives with synergistic relationships with each other based on prevalence and significance. Among the key triggers is a delay in work progress, political instability, adverse weather, social issues, delay in progress payment to contractors and modification of project scope. In conclusion, the triggers of cost overrun in highway projects are contextually driven by the complex nature of the project management, societal, macroeconomic and leadership triggers specific to the Nigerian context. The research was limited to only highway infrastructure projects in Nigeria. Furthermore, the findings are based on a small sample size, and thus, caution must be taken before applying the outcome of this study in a generalised way to other contexts. Practical implications Practically, the stakeholders i.e. client, contractors and consultants should acknowledge the contextual circumstances in which each of the triggers takes place, which will aid in developing pragmatic measures and make the right decisions towards addressing these triggers during any highway construction project in Nigeria and enhance the chances of project success. The context-based approach applied in this study is expected to provide a new insight in understanding the triggers of cost overruns, especially in highway projects in Nigeria and indeed other developing countries with similar governance characteristics