An Evaluation of Wildlife Crossing Design, Placement, Costs, and Funding Opportunities for Corridor Q

About the report:

Construction is underway along Corridor Q, a 14-mile section of highway in Southwest Virginia that will open to traffic in stages from 2023 to 2027.  Preliminary data indicated that a newly established reintroduced herd of elk regularly travels on and alongside the partially constructed road.  The purpose of this study was to determine potential design, placement, costs, and funding opportunities for wildlife crossing structures on Corridor Q should the decision be made to pursue this option to reduce the potential risk for elk-vehicle collisions. 

A criteria-based method was applied to 0.5-mile road segments to determine suitable locations for a series of crossing structures.  Evaluated criteria included elk location data, surrounding land use, landscape features that encourage elk movement, roadside topography for cost-effective structure placement, and structure spacing decisions. Elk location data were obtained from 12 collared female elk in the “Corridor Q herd” (hereinafter “Corridor Q elk”).  These locations were evaluated to determine elk use of the road segments, home range sizes and locations relative to the road, and habitat selection probability. Findings indicated that the use of the landscape by the elk herd has been shaped by the construction of Corridor Q. Approximately 38% of the 26,659 locations of the collared elk were within 200 meters of the nearly completed road sections, which provide elk an efficient means of travel to preferred habitat that is abundant along the roadside.  Home ranges of all 12 collared elk overlapped with portions of Corridor Q road segments.  Home ranges were shaped similarly to the partially constructed sections of Corridor Q, indicating the elk’s heavy use of the road to access preferred areas of habitat on both sides of the corridor.  Distance to barren land, herbaceous cover, and shrub cover had the largest influence on elk habitat selection, all of which are a product of road construction and are distributed linearly along the roadway. 

Construction costs per wildlife crossing structure and associated fencing were estimated to be $5.5 to $5.7 million.  If funding were pursued for wildlife crossing construction, contingency costs and inflation would raise the estimate to a range of $8.2 million (for a bid year of 2025) to $9.8 million (for a bid year of 2028).  With an average elk crash valued at $80,771 and a deer crash at $41,338, 2.8 elk crashes or 5.4 deer crashes per year would have to be avoided per structure for the crash reduction benefits to begin exceeding the cost of a structure and fencing.

This study demonstrated an effective means of incorporating both quantitative elements and qualitative considerations into wildlife crossing design, placement, and cost considerations.  If wildlife crossings are pursued for Corridor Q, the study recommends that the Virginia Department of Transportation consider the structure design and location options provided in this report.

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