John A. Volpe National Transportation Systems Center (U.S.)

DOT-VNTSC-NPS-08-03

Tech Report

Wyoming

John A. Volpe National Transportation Systems Center (U.S.)

AGR-PUBLIC AND TRIBAL LANDS-PUBLIC AND TRIBAL LANDS ; NTL-ENERGY AND ENVIRONMENT-Environment Impacts ;

Sounds associated with oversnow vehicles, such as snowmobiles and snowcoaches, are an

important management concern at Yellowstone and Grand Teton National Parks. The John A.

Volpe National Transportation Systems Center’s Environmental Measurement and Modeling

Division is supporting the National Park Service with its on-going Winter Use Planning

program. As part of this support, acoustic measurements of ten snowcoaches and six

snowmobiles were made at the south entrance to Yellowstone National Park from the 26th

through the 28th of February 2008. Measurement methodologies were guided by SAE J1161

and SAE J192. There were two primary objectives: 1) to determine which snowcoaches had

the Best Available Technology (BAT) with respect to noise emissions, and 2) to determine

if there was a significant difference between snowmobile sound levels when tested using

two revisions of SAE J192. Based on analysis of the data, it appears that among the

snowcoaches, the Yellowstone Expeditions’ modified Dodge B530 snowcoach would be an

excellent candidate for BAT classification. It was also found that measurements guided

by the two revisions of SAE J192 had very similar results.

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VX82 - EM355

Volpe National Transportation Systems Center, Technical Reference Center