ARB Research Seminar

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Assessment of Out-Of-State Heavy-Duty Truck Activity Trends in California

Nicholas Lutsey, Ph.D. Candidate, Co-Principal Investigator, Transportation Technology and Policy, University of California, Davis

October 01, 2007
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA

Press Release
Research Project


The California Air Resources Board emissions inventory estimates indicate that ambient air quality in several regions of California is substantially affected by the exhaust emissions of diesel trucks, many of which may originate and/or fuel out-of-state. Assessing the use of out-of-state fuel in California is important due to the potential air quality impacts of differing fuel composition. Further, out-of-state trucks' characteristics, such as age, influence emissions estimates. In summer 2006 researchers from the Institute of Transportation Studies, University of California Davis (ITS-Davis) conducted an interview survey of truck drivers to quantify the use of out-of-state fuel and characterize the activity of out-of-state trucks in California.

The survey results indicate that 25-28% of Class 8 heavy-duty truck mileage in California is fueled out-of-state. Out-of-state heavy-duty diesel trucks in California account for 14-17% of the operating Class 8 truck population and 26-29% of the Class 8 truck mileage on California roads. These effects are disproportionately concentrated in three air basins - the South Coast, the Sacramento Valley, and the San Joaquin Valley - with considerable ambient air quality standard attainment issues.

Speaker Biography

Nicholas Lutsey is a Ph.D. Candidate and Co-Prinipal Investigator (in colaboration with C. J. Brodrick, Ph.D., Co-Principal Investigator, UC Davis) on this project, as he conducted much of the truck driver surveying and data analysis. He is presently completing his Ph.D. in Transportation Technology and Policy at the University of California Davis. He holds a Bachelor of Science in Agricultural and Biological Engineering from Cornell University. His master's thesis was a quantitative assessment of truck idling behavior and the use of fuel cells as auxiliary power units (APUs) in heavy-duty trucks as a strategy for reducing emissions. His findings contributed to new industry initiatives and both local and federal policy on diesel trucks. After completing his thesis, he held an internship with the California Air Resources Board and later took on a project to analyze the 2005 greenhouse gas agreement between the Canadian government and automakers. For his dissertation, which is supported by a University of California Transportation Center (UCTC) Fellowship, he is creating an analytical tool for evaluating strategies to reduce vehicle-related greenhouse gas emissions. Nicholas Lutsey was the Outstanding Student of the Year for the UC Davis Sustainable Transportation Center for 2006.

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