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CAL-CET Construction Emissions Modeling Tool: Estimating Off-Road GHGs, Air Toxics, & Emissions

CAL-CET Construction Emissions Modeling Tool: Estimating Off-Road GHGs, Air Toxics, & Emissions

California
Emissions Modeling Tool
Emissions Modeling Tool

The Challenge

Caltrans needed a reliable way to estimate emissions from construction activities, including greenhouse gases (GHGs), air toxics, and criteria pollutants. Construction projects involve diverse equipment fleets and complex activity data, making accurate emissions modeling essential for regulatory compliance and sustainability goals. The challenge was to create a robust, user-friendly tool that integrates multiple data sources and methodologies for project-specific emissions estimation. 

Our Solution

Spheros Environmental (formerly Sonoma Technology) collaborated with Caltrans and U.C. Davis to develop the original Caltrans Construction Emissions Tool (CAL-CET) and continues to upgrade the tool with custom features. CAL-CET integrates data from CARB inventories, Caltrans equipment cost and usage reports, and other resources to estimate emissions from on- and off-road construction equipment. We also provided training and created a “Best Practices” package to guide analysts in applying CAL-CET effectively, ensuring quality assurance and innovative approaches for unique project scenarios. 

Client
California Department of Transportation (Caltrans)
University of California, Davis
Practices
Markets
Role
Prime

Results +What makes this unique

CAL-CET provides Caltrans with a comprehensive, data-driven approach to emissions modeling for construction projects. By integrating multiple datasets and offering QA/QC best practices, the tool improves accuracy and usability for analysts. This project stands out for its innovative methodology and collaboration with clients and academic partners, supporting sustainable infrastructure development and regulatory compliance across California’s transportation sector.

Project Experts

Group Manager, Atmospheric and Emissions Modeling
Group Manager, Atmospheric and Emissions Modeling