Exploring a Quantitative and Qualitative Mixed Approach for Estimating Preliminary Engineering Efforts of Bridge Replacement Projects

Abstract

While managing the transportation infrastructure, state transportation agencies (STAs) face multiple challenges. Primary among these are budgetary constraints and understaffing. One task that is impacted by these challenges is that of developing the plans, specifications, and estimates (PS&E) for construction projects. STAs often outsource this job to consultants. The outsourcing itself requires a contract negotiation process, which has historically relied on the work experience of the negotiation parties. PS&E budget development and management relies on an estimate of the engineering man-hours (EMHs). This paper presents a mixed approach to creating that estimate. To identify engineering-related tasks as variables in the estimation of EMHs for the development of PS&E, this approach uses qualitative analysis. The variables identified through qualitative analysis are used to build multiple linear regression models. Data used for this study include project characteristics from the Texas Department of Transportation (TxDOT) and the respective work authorizations from 38 bridge replacement (BR) projects. The results revealed that variables identified through the qualitative analysis are statistically significant to estimate the EMHs of BR projects. However, the improvement in such estimation was found to be marginal. By developing a data-driven approach, this study provides an improved process for estimating EMHs for BR projects—an improvement over the commonly used experience-based approach. This incremental step contributes a method STA staff can use to make better-informed decisions during the contract negotiation process undertaken while outsourcing preliminary engineering (PE) work.