IDENTIFICATION OF THE UNCERTAIN EVENTS IMPACTING ON CONSTRUCTION TIME OF SOUTH AFRICAN HIGHWAY PROJECTS

Abstract

This article examines the uncertain events encountered in the construction process of highway projects in South Africa, so as to evaluate their impact on the construction time of such projects. The rationale for this examination stems from the view held by scholars that highways are complex projects initiated in dynamic environments, which are often beset by different uncertainties and a lack of appropriate evaluation of the uncertain events that occur during the construction process. The research made use of a review of existing literature in the area of uncertainty management and modelling in infrastructure projects, to guide the direction of the study, brainstorming, and interviews conducted with highway experts to identify the factors of uncertainty that impact construction time on infrastructure projects. A simple uncertainty matrix for South African highway projects was developed using a quantitative model and descriptive statistics. It emerged from the study that the uncertain events that affect the construction time of highway projects are distributed across economic, environmental, financial, legal, political, social and technical factors. Also, it was found that each factor contains several uncertain events, which impact on construction time differently, through a combination of the uncertain events of the individual construction activities. Based on the findings, it can be concluded that construction time on South African highway projects is significantly related to the social and technical factors of uncertainties. The matrix developed will be useful in modelling uncertainty of the cost and time of individual construction activities in highway projects.