Article

Abstract

• Traditional design–bid–build guidelines suggest that engineering estimates should be within +/−10% of the lowest contractor bid and recommend this value as a reference to identify anomalies in the bidding process. This guidance, however, neglects delivery approaches such as design–build (D–B). This research examines 305 D–B highway projects procured using best-value and identifies the underlying reasons for bid dispersion and cost estimates inaccuracies. This study found an average bid dispersion of 27%, suggesting that a larger threshold (i.e., 25%) is needed to account for the inherent variability of D–B projects. This study also found that engineering estimates are on average 2% more than the awarded price. This result contradicts findings in existing literature and suggests that current practice in D–B best-value may be more conservative than other procurement methods. The study explores four potential reasons for bid dispersion and engineering estimate inaccuracies and suggests strategies for improvement. By providing a better understanding of bid dispersion and engineering estimate accuracy, this study will ultimately assist in the development of new policies and processes for D–B best-value projects.

Creator

• Gaikwad, Suraj V
• Torres-Machi, Cristina
• Calahorra-Jimenez, Maria
• Molenaar, Keith Robert

Date Issued

• 2021

Academic Affiliation

• Civil, Environmental and Architectural Engineering

Journal Title

• Journal of Construction Engineering and Management

Journal Issue/Number

• 7

Journal Volume

• 147

Last Modified

• 2023-07-11

Resource Type

• Postprint

Rights Statement

• In Copyright

DOI

•  https://doi.org/10.1061/(ASCE)CO.1943-7862.0002104

ISSN

• 1943-7862

Language

• English [eng]

Relationships

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