Investigating cost overruns and delay in urban construction projects in Iran

Urban construction, as one of the most important sectors of construction industry in Iran, commonly faces significant cost overruns and delay. The main objective of this study is to evaluate how small, medium and large urban construction projects perform in terms of cost and time. Moreover, different types (road or building) and nature (new or renovation) of construction projects are considered in this research. This study looks at the urban construction projects in Karaj, the capital of Alborz Province, Iran. In this study, 72 urban construction projects are surveyed by reviewing their documents and their real performance. To analyze the collected data, the statistical analyses including class range analysis, independent-sample T-test and correlation analysis are used. This study shows that large urban construction projects are faced higher cost overruns and delay. Moreover, the time- and cost-performance of the new-build projects in overall is better than renovation projects. Furthermore, the cost-performance of urban road projects is better than building projects. The findings offer descriptive statistical cost and time performance information to support realistic time and cost estimation in urban construction projects.