Benefit-cost analysis (BCA) is a commonly used approach to evaluate transportation projects for potential funding. Current methods for conducting BCA for wildlife mitigation projects typically do not include the value of wildlife or the residual value of larger wildlife crossing structures. Our team examined the BCA methods currently used within the Colorado Department of Transportation (CDOT) to determine how to incorporate the additional considerations as mentioned above specific to wildlife-highway mitigation projects, so that a more relevant BCA of these types of projects is performed. In the United States, most state transportation agencies do not include the value of wildlife killed in collisions with vehicles when conducting a BCA. Where wildlife values are considered, current methods include statutory values assigned by a state legislature for wildlife that are unlawfully taken or using the hunting value of the animal expressed as the probability that an animal will be successfully harvested by a hunter. However, both of these approaches likely underestimate the economic value of mule deer and elk in relation to their benefits to Colorado's economy. To address these limitations, we worked with CDOT and Colorado Parks and Wildlife to develop an alternative approach based on the accepted economic theory of contingent valuation, which is used to assign dollar values to nonmarket resources. Using this technique, we were able to calculate values for mule deer and elk in Colorado. Though still conservative, these values provide a justifiable and more comprehensive estimate of the actual value of these species to Colorado's economy for inclusion in BCA. A second major consideration for a more comprehensive BCA for wildlife mitigation projects relates to the analysis period used in BCA. Typically, this analysis period is 20-30 years; however; this timeframe is much shorter than the actual design life of large wildlife crossing structures, which may exceed 75 years. To assess the value of the asset beyond the BCA analysis period, we integrated a calculation of residual value for wildlife crossing structures into the BCA. These additional values were incorporated into a comprehensive BCA approach. An automated spreadsheet was developed to calculate the benefit-to-cost ratio based on the inputs provided by the user, including the length of the highway segment, the number and types of mitigation features, and the 10-year crash history of reported wildlife-vehicle collisions, as well as the number of deer and elk involved in those collisions. The result is a practical tool that uses a more comprehensive methodology consistent with current Federal Highway Administration guidance for conducting BCA. Results from this tool can be used by CDOT and its partners to evaluate the benefits and costs of wildlife-highway mitigation projects for purposes of transportation planning, wildlife mitigation prioritization and eligibility for potential funding sources.
Planning for Transportation Ecology
Benefit Cost Analysis