Critical design factors leading to cost overruns on road construction projects in Uganda

Abstract

Often times road construction projects do experience cost overruns hence they are not completed within budget necessitating more resources to be allocated. The majority of these overruns are caused by design factors occurring during the design stage. This study therefore focused on identifying the critical design factors leading to cost overruns during implementation. A questionnaire for the survey was developed based on a list of 29 design factors identified from the literature review. These factors were ranked according to their relative importance index which was a combined effect of both their frequency of occurrence and severity. Feedback was received from 63 respondents against a target of 75 distributed amongst contractor, client and consultant staff. The data from the questionnaire was statistically analyzed using SPSS v20 and a hierarchical assessment of the factors using relative importance index revealed that the top most five significant design factors leading to overruns were underestimation of earthwork quantities, less volumes of cut and fill, inadequate geotechnical investigations, inadequate material investigations and addition of extra works not in the original scope. It was recommended that sufficient time and budgetary resources coupled with capacity building of staff is undertaken in order to mitigate the impact of these factors on the final cost of the project.