2005. Guidelines for Engineering Analysis of Motorized Mixed Use on National Forest System Roads. EM7700-30P. San Dimas, CA: U.S. Department of Agriculture, Forest Service, San Dimas Technology and Development Center. 32 p.
Over the past few decades, the availability and capability of off-highway vehicles (OHVs) have increased tremendously. More people are enjoying access and recreational opportunities on their national forests and grasslands, in keeping with the U.S. Department of Agriculture (USDA) Forest Service's multiple use mandate. However, the increase in OHV use can also affect soil, water, wildlife habitat, other recreational visitors, and the introduction of invasive plant species. Today, unmanaged recreation, including impacts from OHVs, represents one of four key threats facing the nation's forests and grasslands. The USDA Forest Service is revising regulations and directives for motor vehicle use on national forests and grasslands.
National Forest System (NFS) roads are designed primarily for use by highway-legal vehicles (motor vehicles that are licensed or certified for general operation on public roads within the State) such as a passenger car or log truck. Some NFS roads also provide recreational access for all-terrain vehicles and other non-highway-legal OHVs. For the purpose of this document, motorized mixed use is defined as designation of a NFS road for use by both highway-legal and non-highway-legal motor vehicles. Designating NFS roads for motorized mixed use involves safety and engineering considerations.
Qualified engineers may use these guidelines to analyze any NFS road being considered for motorized mixed use. The baseline for the analysis will be Forest Service regulations and directives and applicable State and local laws. The qualified engineer will determine how detailed the analysis is to be and may choose to do an evaluation based on factors in these guidelines or other factors. The qualified engineer determines the factors to be considered for the specific road, road segment, or road system being analyzed in consultation with recreation managers or others familiar with operation of non-highway-legal vehicles and with travel management cooperators. The level of analysis is to be based on personal knowledge, expertise, and experience.
Based on the analysis conducted, the qualified engineer will identify risks and prepare documentation for the appropriate responsible official. The analysis may include mitigation measures that would reduce the risk associated with designating the road for motorized mixed use. The basis of the analysis will be the exercise of engineering judgment or, if the issues are more complex, an engineering report.
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