Preliminary Cost Estimate Model for Culverts

Abstract

The construction of modern high-speed motorways has increased over the last decade all over the world. However, the financial crisis led many financial institutions worldwide to impose stricter credit limitations and seek to finance only high-profit investments. As a result, the financing of transport projects was made even more difficult. At the same time, accurate cost estimates at the preliminary stages of a project are essential to all the major project stakeholders, since they are necessary for the budget determination, allocation and monitoring, the comparison of alternative projects and technical solutions and finally, the selection of the projects to be implemented. However, the degree of accuracy required is very difficult to be achieved at the preliminary stages due to the limited extent of available information.This paper presents a preliminary predesign cost estimate model for culverts i.e. conduits for the passage of surface drainage water under the motorway. Although individual culverts present low construction cost when compared to bridges, tunnels or large retaining walls, their total number along a motorway is significant and thus, their total construction cost is also substantial. The proposed model utilizes a properly developed database derived from actual construction projects to produce accurate quantity estimates by means of the statistical technique of linear regression. Following the estimation of quantities, proper material unit prices are applied for quick and reliable cost estimates to be provided. The proposed model only requires limited input and thus, can be used in the early project stages, offering valuable contribution towards the accurate culverts’ cost prediction in motorway projects.