Document Type
Document
Publication Title
TxDOT Report 0-7184-01
Publication Date
2025
Abstract
Texas Department of Transportation (TxDOT) determines unit prices of pay items using the historical bids-based estimation method and then develops an engineer’s project appraisal. The engineer's estimate is used to assess the bids and select the bidder. However, the unit price of a work item is heavily affected by various project-specific and external factors, including but not limited to the project location, the quantity of the work, project complexity, time factors, and macroeconomic conditions. Therefore, accurate and reliable unit price estimation based on these project-specific and external factors is vital for the optimum use of the available project budget. The project objectives included: (1) conducting an overview analysis of factors affecting unit prices, (2) identifying factors affecting unit prices in Texas, (3) creating a unit price estimation database, (4) creating a spatio-temporal unit price estimation model considering the factors affecting unit prices, (5) developing a GIS-based visualization tool, and (6) implementing, demonstrating, and validating the interactive unit price estimation and GIS-based visualization tool on six Receiving Agency’s projects. The factors that affect unit prices of construction line items were identified with an extensive literature review. Then, we collected data on various project-specific factors and external factors (i.e., independent variables) and the bidder’s estimate and the TxDOT engineer’s estimate (i.e., dependent variables). Using that dataset, spatiotemporal unit price estimation models were developed to predict the TxDOT engineer’s unit price estimate and the bidder’s average unit bid price. Finally, a GIS-based unit price estimation and visualization tool (UPEVT) was created, and we used the tool for estimating unit prices of a few line items in six Texas projects to demonstrate the tool’s application. The UPEVT enables TxDOT personnel to visualize the historic unit price data. Implementing this system facilitates quick data retrieval and visualization across different geographic locations.
Recommended Citation
Shahandashti, M., et al. (incl. Paydarzarnaghi, M.). Develop an Interactive Unit Price Estimation and Visualization Tool. Texas Department of Transportation.
Comments
This research project is supported by the Research and Technology Implementation (RTI) Division of the Texas Department of Transportation (TxDOT). We would like to thank the Project Monitoring Committee (PMC) members: Danny Souraphath, Andrea Ranft, Sam Kent, William Allen, Alonzo Balderaz, James Padilla, and Nehal Atlam for their coordination with the research team in ensuring the smooth execution of this project.