Off-road gasoline mobile sources, including vegetation control measures, emit a significant part of gasoline-powered mobile source related HC and NOx exhaust and evaporative emissions (roughly 30% in California, >15% in New York State). Although both on-road and off-road emissions are trending downward as a result of state regulations, the off-road percentage contribution to the total gasoline-related mobile source inventory is increasing. From the exposure perspective, a large segment of the population uses small, gasoline-powered spark-ignition (SI) lawn and garden equipment on a regular basis. Emissions from many of the small SI engines powering this equipment may lead to elevated air pollution exposures for a number of gaseous and particulate compounds, especially for individuals whose occupations require the use of these engines daily, such as landscapers and the vegetation control personnel at state/local DOTs. Emission studies with lawnmowers suggest a potential for high exposures during the equipment operation. Research literature has reported elevated CO personal measurements related to chainsaw use, with short-term concentrations exceeding 400 ppm for certain cutting activities.

These issues of emissions, exposure, and energy consumption associated with vegetation controls are of particular concern to New York State Department of Transportation (NYSDOT), which owns about 1% of the land in New York State, much of which is associated with highway right-of-way (ROW). In order to properly manage the ROW, a variety of oftentimes competing risks must be identified, evaluated and prioritized. In particular, knowledge about energy expenditure and emissions from ROW management practices, identification of factors that affect such energy consumption and emissions, and scientifically-based recommendations of practical guidelines in these operations are desirable for the NYSDOT to implement successful fuel saving and emission control strategies.

The purpose of this project is to quantify emissions and energy consumption associated with various vegetation control measures by providing real world assessment of the emissions and fuel use associated with NYSDOT ROW vegetation management. The project is designed to measure exhaust emissions for typical ROW vegetation control field operations. Emissions factors can be developed from these measurements, and extrapolated to a state or regional scale using the project data in combination with specific fleet operation information. The emissions factors will then be used to model various scenarios to assist in selection of maintenance practices that minimize the impacts associated with vegetation management.