Shrestha, P.P., Pradhananga, N. and Mani, N.
KSCE Journal of Civil Engineering, 1-9.
Publication year: 2014

In the United States, the majority of public road projects are constructed using the Design-Bid-Build (DBB) method. DBB projects are procured by government agencies typically through the competitive bidding process. In DBB projects, the early estimates of probable cost of road projects is one of the major factors in making decision regarding which projects proceed to the bidding stage. The final cost of the project will be fixed based on the bid amount of the contractor. If the cost of the project can be estimated based on the bid cost from the historical data, the estimated amount will be more accurate. This study attempted to determine the bid cost of projects by analyzing the bid data of 151 DBB road projects undertaken by the Clark County Department of Public Works in southern Nevada from 1991 through 2008. The total value of construction was equivalent to $841 million when converted into a June 2011 base cost. This study developed regression models to predict a future project’s bid cost of unit price items, based on the quantities of items. The validation of models also showed that these models predicted the unit bid cost accurately. These models will assist in assessing the effect of quantity in accurately estimating the cost of the unit price items and reduce variances that result in large discrepancies between engineers’ estimates and actual bid-award amounts.