Using parametric modeling to estimate highway construction contract time

Federal regulations require that state transportation agencies have written procedures for setting the construction contract time for highway projects. Since the institution of those regulations, state agencies have used a variety of methods to estimate and set contract time. FHWA recommends the use of methods based on production rate and activity precedence and logic in this process. For years, the Kentucky Transportation Cabinet used a system based around these requirements and recommendations only to find that the system produced estimates varying widely from actual construction times. The use of parametric modeling and historic contract times produced a system that more accurately estimates contract times and with an associated Microsoft Excel-based tool is more user friendly. This approach used project cost and bid item quantity data in multivariate regression-based modeling to develop a set of equations that provide the Kentucky Transportation Cabinet with contract time estimates for projects in a matter of minutes by using data readily available at later design stages.