Highways retrofitted with overpasses and underpasses for wildlife use have been implemented in the United States and the world. The observed level of mortalities of mule deer and other wildlife species on U.S. highways appears to have negative consequences on wildlife population. Studies in other states indicate that more than 50% of the deer-vehicle collisions nationwide are not reported and there are no records for deer-vehicle collisions that occurred in remote areas although records for collisions within or near urban areas may be reported. The primary objective of this study is to evaluate the effectiveness of wildlife overpasses, using a case in the State of Nevada. The 4.1-mile study section is along the U.S. 93 Highway in Elko, NV, with 3 miles of fencing on both sides of the highway. This thesis focuses on evaluating the level of effectiveness of the overpass in reducing deer-vehicle collisions. An Empirical Bayes approach was applied to compare the `before' and `after' crash changes. A benefit-cost analysis of the wildlife overpass is also included to identify its effectiveness considering factors like number of mortalities, deer-vehicle collisions threats to human injuries or fatalities, and the construction costs.

TRB¿s National Cooperative Highway Research Program (NCHRP) Report 615: Evaluation of the Use and Effectiveness of Wildlife Crossings explores development of an interactive, web-based decision guide protocol for the selection, configuration, and location of wildlife crossings.

The US 93 reconstruction project on the Flathead Indian Reservation in northwest Montana represents one of the most extensive wildlife sensitive highway design efforts to occur in the continental United States. The reconstruction will include installations of 42 fish and wildlife crossing structures and approximately 15 mi (24 km) of wildlife exclusion fencing for a total investment of over 9 million dollars. This report documents the success of using a context sensitive approach to collaboratively redesign a rural highway within a multiple use landscape that accommodates the needs and concerns of different institutions, cultures and priorities. Further, this report introduces baseline field data collection methods and results that are being used to evaluate how the wildlife crossing structures and wildlife fencing affect deer and bear vehicle collisions and movements in a multiple use rural landscape. The preconstruction data summarized here, and in combination with complementary post construction data, will address the following goals of the evaluation study: (1) determine what effect US 93 wildlife crossing structures and fencing have on the frequency of animal vehicle collisions and successful animal highway crossings; (2) document the design decision making processes and lessons learned as a case study; and (3) identify best management practices and further research. These issues are addressed via a literature review of important considerations related to locating, designing, and evaluating the effectiveness of wildlife crossings and exclusion fencing; a case study and project history; summary and synthesis of field data collection efforts; overview of other relevant and repeatable field studies; and a discussion about the measures of effectiveness and post-construction data collection recommendations. The ultimate value of the information in this report will be realized when the reconstruction is complete and post construction field data is collected to comparatively assess the effect of the wildlife mitigation on the parameters of interest identified in the goals. Perhaps one of the most important insights gained from the preconstruction research is that, due to the myriad sources of unquantifiable variation in the environment, many years of monitoring are necessary to make valid inferences. Given the paucity of long term, before after field studies assessing the effects of wildlife exclusion fencing and crossing structures on wildlife and driver safety, the US 93 wildlife mitigation evaluation, when completed, will provide useful results, lessons learned, and best management practices to guide other wildlife mitigation efforts in the future.

A central goal of transportation is the delivery of safe and efficient services with minimal environmental impact. In practice, though, human mobility has flourished while nature has suffered. Awareness of the environmental impacts of roads is increasing, yet information remains scarce for those interested in studying, understanding, or minimizing the ecological effects of roads and vehicles. Road Ecology addresses that shortcoming by elevating previously localized and fragmented knowledge into a broad and inclusive framework for understanding and developing solutions. The book brings together fourteen leading ecologists and transportation experts to articulate state-of-the-science road ecology principles, and presents specific examples that demonstrate the application of those principles. Diverse theories, concepts, and models in the new field of road ecology are integrated to establish a coherent framework for transportation policy, planning, and projects. Topics examined include: foundations of road ecology roads, vehicles, and transportation planning vegetation and roadsides wildlife populations and mitigation water, sediment, and chemical flows aquatic ecosystems wind, noise, and atmospheric effects road networks and landscape fragmentation Road Ecology links ecological theories and concepts with transportation planning, engineering, and travel behavior. With more than 100 illustrations and examples from around the world, it is an indispensable and pioneering work for anyone involved with transportation, including practitioners and planners in state and province transportation departments, federal agencies, and nongovernmental organizations. The book also opens up an important new research frontier for ecologists.