01516017

Component

The purpose of this paper is to propose a rational method for determining a design cost contingency. The contingency in design is to account for risks such as scope creep and lost design effort throughout the process. In design of transportation projects, the required function of a project is usually well-defined but the amount of time needed to complete the design is difficult to quantify. The proposed method to calculate design contingency can be used by an agency to augment its current method to estimate consultant design fees. This paper details a method for creating a design cost estimate accuracy index from historical budgeted and actual design fee data. The index can be used on future projects to determine an appropriate design contingency. The paper demonstrates the validity of the proposed method by example comparing the data from 26 actual projects from 9 different agencies with published design fee curves from the American Society of Civil Engineers and the Institute of Professional Engineering New Zealand, using linear regression. Since coefficients of determination (R² values) exceeded 0.95, the paper concludes that the use of the design contingency will enhance the accuracy of design fee estimates.

This paper was sponsored by TRB committee AFH10 Construction Management. Alternate title: Rational Method to Determine Design Cost Contingency for Consultant-Designed Highway Construction Projects.

01503729

14-3967

English

15p

2014

Transportation Research Board 93rd Annual Meeting

Digital/other

Figures; References; Tables

Consultants; Cost estimating; Costs; Highway design

Cost contingencies

Administration and Management; Design; Economics; Highways; I10: Economics and Administration; I20: Design and Planning of Transport Infrastructure

Transportation Research Board Annual Meeting 2014 Paper #14-3967

TRIS, TRB, ATRI

Jan 27 2014 3:22PM