AN EVALUATION OF WILDLIFE CROSSINGS FOR MULE DEER AND OTHER WILDLIFE IN NEVADA

1. AN EVALUATION OF WILDLIFE CROSSINGS FOR MULE DEER AND OTHER WILDLIFE IN NEVADA Ivy Attah Zong Z. Tian (PhD) Center for Advanced Transportation Education and Research Department of Civil & Environmental Engineering University of Nevada, Reno Email: ivyous2000@yahoo.com

2. Outline • Introduction • Background • Methods • Results • Conclusions

3. Introduction • Observed high mortalities of mule deer along U.S Highway 93 in Elko County. • During Spring and Autumn migrations. • 75 - 150 known deer killed seasonally; estimated total of approximately 300 deer killed per year. • This lead to construction of several overpasses and underpasses to mitigate issue.

4. Background • Approximately 1.5 million deer-vehicle collisions occur resulting in: • Over 29,000 human injuries, 200 human fatalities, 1.3 million deer fatalities, and over 1 billion dollars worth of property damage in the United States. • 200,000 deer killed on U.S. roadways in deer vehicle collisions in 1980. • An estimate of more than 538,000 deer killed by vehicles in the United States in 1991. • In 2002, NDOT reported 698 collisions between large ungulates and motor vehicles throughout the state.

5. Objectives • Evaluate the effectiveness of the US Highway 93 wildlife overpass in reducing DVCs by conducting: • A Before-After study on crash reductions • A Benefit-Cost Analysis • Analyze discrepancies with DVC data and Carcass removal data

6. Deer Collisions by Month on US 93 of Wells, NV FOR 2000-2004

7. Methods Overview

8. Methods Overview Cont.

9. Methods Overview Cont. • Benefit-Cost Estimate- • Purpose- To determine the economic justifiability of having wildlife crossings at high deer vehicle locations. • Quantifies and compares benefits and costs of a project to determine if it is a sound investment. • Costs- Largely construction oriented in present terms (design, implementation, maintenance and removal efforts) • Benefits- Distributed more uniformly over the life of the project. • Includes savings accrued by reducing the number of crashes. • Effectiveness of mitigation measures in reducing collisions

10. Case Study • Before-After Study ʎ = L rc = N/M = 2/17 = 0.1176 π = rcK = 0.1176*30 = 3.528 δ = π- ʎ = 2.528, thus a reduction in the expected number of crashes by 2.53.

11. Case Study Cont. • E-B Method • SPFNEVADA = Cr*SPF • SPF = 0.02652×ADT^0.53, AMF=0.95

12. Case Study Cont. Thus, the expected accidents = 24.72 ± 2.09 accidents in 10yrs.

13. Case Study Cont. • Benefit-Cost Analysis (i = 4%, n = 40 years)

14. Case Study Cont. NPW = {(DC) (PD) + (IC) (PI) + (FC) (PF)} (N) (PWF) – {CC + (MC) (PWF)} NPW = {7625.16 *0.9591 + 91,091.74*0.0407 + 3,068,359.10*0.0002} (10.4*3.5*0.90)*19.79– {2,329,598+3,363*19.79) NPW= $5,146,665million B/C ratio = 3.15

15. Wildlife Crossings US 93 in Wells, Nevada Overpass Underpass

16. Practical Results

17. Conclusions • The Empirical Bayes method provides a more accurate estimate compared with other methods. • Combines crash counts with knowledge about the safety of similar entities • Corrects the regression-to-the-mean bias • A reduction of 17.6% crashes gives overpass some credibility of effectiveness • A B/C ratio of 3.15 proves that wildlife crossings are economically justifiable.

18. Thank You!Slow down for Deer