Challenges in Engineering Estimates for Best Value Design–Build Highway Projects

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.

• Record URL:
  https://doi.org/10.1061/(ASCE)CO.1943-7862.0002104
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/8675438
• Supplemental Notes:
  • © 2021 American Society of Civil Engineers.
• Authors:
  • Gaikwad, Suraj V
  • Calahorra-Jimenez, Maria
  • Molenaar, Keith R
  • Torres-Machi, Cristina
• Publication Date: 2021-7

Language

• English

Media Info

• Media Type: Web
• Features: References;
• Pagination: 04021065
• Serial:
  • Journal of Construction Engineering and Management
  • Volume: 147
  • Issue Number: 7
  • Publisher: American Society of Civil Engineers
  • ISSN: 0733-9364
  • EISSN: 1943-7862
  • Serial URL: http://ascelibrary.org/journal/jcemd4

Subject/Index Terms

• TRT Terms: Accuracy; Cost estimating; Design build; Estimates; Highway engineering; Procurement; Road construction
• Subject Areas: Administration and Management; Construction; Finance; Highways;

Filing Info

• Accession Number: 01778012
• Record Type: Publication
• Files: TRIS, ASCE
• Created Date: Jul 28 2021 1:41PM