Examining of Project Cost Overrun in Project Management: A Case Study of the Road Development Agency in Lusaka

This study investigated the persistent problem of cost overruns in road construction projects managed by the Road Development Agency (RDA) in Lusaka. Recent evidence showed that 78% of projects had exceeded their budgets by an average of 52%, with flagship projects such as the Lusaka-Ndola dual carriageway, Kafue Road expansion, and the Lusaka Decongestion Project recording significant financial escalations. These overruns not only consumed a large share of Zambia’s infrastructure budget but also resulted in delays, reduced quality, and premature defects, raising concerns about long-term sustainability. Guided by Agency Theory, the study examined the causes and consequences of these overruns, focusing on systemic weaknesses in planning, procurement, financial management, and stakeholder relations. A single-case study design was applied, drawing data from 60 respondents, including engineers, contractors, project managers, and government officials. Both qualitative and quantitative approaches were employed through questionnaires, interviews, and document analysis. Findings revealed that weak project planning, inaccurate cost estimation, and political interference were key drivers of cost overruns. The Pearson chi-square test (χ 2 (9)=100.0206; Pr = 0.000) showed a significant relationship between the role of the respondent and their perception of the causes of cost overruns, indicating that different roles had varying perspectives on the root causes. Additionally, a strong association was found between delays in contractor payments and cost overruns leading to project delays, as evidenced by a Cramér’s V value of 0.8147. The study further showed that overruns negatively impacted project timelines, scope, quality, workforce morale, and public trust in the RDA. Stakeholder engagement was identified as a critical but underutilized tool for mitigating cost overruns, with challenges such as conflicting interests, weak coordination, and limited transparency undermining its effectiveness. The study concluded Tackling this problem required a holistic approach that addressed project management practices and also included transparent, collaborative, and proactive stakeholder engagement to build trust and improve accountability.