Glossary of Terms

Here are a few of the terms and acronyms used throughout this website and in the debate over Maclay Bridge:

• ADT  Average Daily Traffic count
• BCC – Board of County Commissioners.
• BO – Section 7 Biological Opinion.
• CE – Categorical Exclusion.
• DNRC – Montana Department of Natural Resourcs & Conservation 
• EA/FONSI – Environmental Analysis/Finding of No Significant Impact.
• Engineering Standards – Maclay Bridge does not meet modern engineering standards, a statement of the obvious. This is often thrown out to shut down opposition to replacement of the bridge, but by constructing a new South Avenue Bridge as planned simply connects a modern, two-lane bridge to a sub-standard network of rural roads for which there is no upgrade plan. The west end of South Avenue is presently classified as county rural road. Immediately upon opening the new bridge, it will become a collector, for which it does not meet current county standards, which are lower than state or federal standards.
• EIS – Environmental Impact Statement.
• FEMA – Federal Emergency Management Agency.
• FHWA – Federal Highway Administration.
• Fracture Critical – This is a term often misused to imply an unsafe or impending unsafe condition. “Fracture critical” is a common engineering term to indicate lack of redundancy in the structure, meaning if the supporting span structure is damaged, the whole bridge could be endangered. Many modern fracture critical bridges are designed and built today.
• Functionally Obsolete – New York’s Brooklyn Bridge is “functionally obsolete.” This is another term commonly used to degrade a bridge, but it is a useful term when used properly. It can be an effective classification applied to a structure that scores below a thresh-hold of “50” when grading elements applied to the sufficiency rating score. The primary contributing elements for Maclay Bridge are the single-lane and the bridge approaches based on traffic count.
• FWP – Montana Department of Fish, Wildlife & Parks
• FWS – U.S. Fish and Wildlife Service.
• HDR – The engineering firm hired by Missoula County to work on the Maclay Bridge Project. Formerly Henningson, Durham & Richardson, Inc.
• MDT – Montana Department of Transportation. MDT Public Involvement site.
• MOA – Memorandum of Agreement
• MEPA – Montana Environmental Policy Act.
• NEPA – National Environmental Policy Act.
• NHPA – National Historic Preservation Act (pdf). (Advisory Council on Historic Preservation website).
• Structural Deficiency – A very ambiguous term that can mean anything from a bent hand rail to a failing support structure.
• TDC – Technical Design Committee.