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Project at a Glance

Project Status: complete

Title: Microscale emissions modeling system.

Principal Investigator / Author(s): Gerfen, Jeffrey Brian

Contractor: California Polytechnic University

Contract Number: 96-316

Research Program Area: Emissions Monitoring & Control

Topic Areas: Mobile Sources & Fuels, Modeling


The Microscale Emissions Modeling System is a mobile roadside utility that estimates vehicle emissions for a section of roadway. The system utilizes three laser rangefinders to estimate vehicle speed and acceleration and trigger a license plate reader (LPR) for vehicles passing through a selected lane of traffic. A record of speed, acceleration and license plate number is created for each vehicle that passes during a data collection session. The Microscale Emissions Modeling System post-processes the vehicle records to estimate the emissions of each vehicle. The emissions estimates are based on empirically derived lookup tables provided by the ARB Planning and Technical Support Division. These tables relate vehicle emissions to speed, acceleration and vehicle technology type.

The Microscale Emissions Modeling System was developed inside a full-size passenger van that is capable of self-contained operation on the side of the roadway. The complete system includes mast-mounted laser rangefinders, on-board processing and database computers, and a commercial license plate reader. Roadside testing has indicated that this rangefinder-based system is a viable approach. The installed rangefinders suffer from cross interference, making speed and acceleration measurement unreliable and hence emissions estimates inaccurate. Upgrading the laser rangefinders to units that do not suffer from interference will solve this problem and give reliable system operation.


For questions regarding this research project, including available data and progress status, contact: Heather Choi at (916) 322-3893

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