Overview
This report presents an advanced method for calculating highway construction cost indexes (HCCIs) for the Montana Department of Transportation (MDT). It combines a dynamic item basket, which selects bid items to reduce small-sample error, with multidimensional indexes that reveal trends by project type, size, location, and market sector.
The study integrates these methods in the MDT HCCI Calculation and Bid Analysis System and evaluates the system using historical MDT bid data. The resulting indexes included eight times as many bid items and at least 20% more total bid cost than the prior method. They also revealed different cost trends across sectors, including bridge construction and the overall highway market.
The system is intended to support more informed budgeting and planning, highlight cost growth across project types and locations, and help agencies investigate relationships such as cost and quality.