HIGHWAY PROJECTS

The Nigerian construction industry is expanding at a rapid rate both in terms of complexity and volume, with that comes a host of issues with project cost and time overruns being at the top. As a result of this, it has become important to conduct this study with the aim of developing cost and time models that can be used by stakeholders in the construction industry. The objectives of this study are to: determine the relationship between cost per kilometer and cost overrun in Nigeria, ascertain the relationship between cost per kilometer and time overrun in Nigeria, analyze the relationship between initial cost and cost overrun in Nigeria and determine the relationship between initial time and time overrun in Nigeria. Secondary data of a population size of 229 extracted from a document released by the Federal Ministry of Works and Housing in 2017 on the ongoing highway projects in Nigeria was the source of data for this study. Linear regression was the form of analysis performed in order to develop the models in this study. The models obtained in this study are as follows:
C1 = -4.681 x 10
10 + (5.946 x 10
9) Log Ckm + εi, T1 = -322.174 + (58.454) Log Ckm + εi, C1 = -4.336 x 10
9 + (1.088) C0 + εi, T1 = -15.463 + (1.333) T0 + εi. The four models developed posted R2 values, ranging from ≥10% to ≤30%. In conclusion, the relationship between the initial cost of highway projects and its corresponding cost overrun posted the highest R2 value of 30.2% with an adjusted R2 value of 29.1%. This study recommends that reliable cost and time models should more often than not be utilized in predicting the actual time and cost it would take to complete a highway project in Nigeria.