Ammar, T; Abdel-Monem, M and El-Dash, K (2025) Regression-based model predicting cost contingencies for road network projects. International Journal of Construction Management, 25(11), pp. 1273-1287. ISSN 1562-3599
Abstract
Cost contingencies represent a significant markup percentage for construction projects. Many construction projects experience cost overruns due to unexpected events before or during the construction phase. Determining the cost contingency for construction projects is one of the most frequent and widespread financial problems many countries face. Since the amount included in the estimates is always insufficient to absorb the actual cost overruns of the project. The main objective of this paper is to develop a simple realistic regression model for predicting the appropriate contingency amount for road network projects before the bidding stage. The regression model has been developed based on data from real case studies for 75 road network projects to adequately consider all potential risks may face the project. Good-of-fit tests were used to select the best-fitting statistical distribution for a given dataset. Based on the analysis of selected data, the log-logistic probability distribution function is the best-fit curve representing cost overrun behavior, and the cumulative distribution function has been used to determine the realistic probability of incurred cost overrun. Based on the analysis of real case studies, it is suggested that an average of 59.722% be used as a cost overrun contingency amount for road network projects. The study outcomes will help practitioners and researchers improve future accuracy/calculations of contingency amount for road construction projects and improve the decision-making process.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | contingency prediction; cost overrun; probability distribution; regression model; road networks |
| Index terms: | probability distribution, cost overrun, decision-making process, case study, regression model, construction phase, estimate, road construction, accuracy, overrun, face, actual cost, bidding, dataset, practitioner, distribution function, construction project |
| Subjects: | psychology, bidding, practitioner, production management, project delivery, financial and cost management, data collection methods, data management, project controls, decision analysis, statistical analysis, civil engineering, probability and distributions, professional development |
| Topics: | Cost Management, Information Management, Research Practice, Roles and Professions, Digital Applications, Organizational Design, Time Control, Engineering Principles, Project Management, Risk Management, Procurement |
| Descriptive scope: | 4 PCEA |
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