Impact of Wildlife Crossing Structures on Wildlife–Vehicle Collisions

Abstract

This paper examines whether wildlife crossing structures reduce the number of wildlife–vehicle collisions. Using Washington state crash data from 2011 to 2020, I employed a difference-in-differences methodology at the year level on each of 13 observed wildlife crossing structures in Washington. The treatment area consisted of wildlife–vehicle collisions within 10 mi of a wildlife crossing structure, and the control area included wildlife–vehicle collisions that were 60 to 70 mi from the same wildlife crossing structure. I found evidence that wildlife crossing structures resulted in one to three fewer wildlife–vehicle collisions on average per mile per year. The marginal treatment effect also held within a 5-mi treatment area, a 15-mi treatment area, and when controlling for the presence of other structures within the baseline of a 10-mi treatment area. However, the collision reductions were more consistent among wildlife bridges than culverts, suggesting that not all wildlife crossing structures have the same effect in reducing accidents involving wildlife. Using a back-of-the-envelope approach, each wildlife crossing structure yielded annual benefits of $235,000 to 443,000 in 2021 U.S. dollars.

Calculating Indicators From Global Geospatial Data Sets for Benchmarking and Tracking Change in the Urban Environment

“…▪ This indicator does not currently address roadways as particular dangers to animals, despite the well-documented role vehicle collisions play in harming wildlife (Sugiarto 2022). We would like to integrate roadway information into our implementation of future versions of this indicator.…”

Trends and Characteristics of Human Casualties in Wildlife–Vehicle Accidents in Lithuania, 2002–2022

“…As for WVAs in Lithuania, Vision Zero foresees a drop in the number of such accidents on state roads to five per year, which would be a decrease of 83% [13]. Various countries approach the target of WVA mitigating by means of directional fencing [14] and wildlife passages [15] as well as planning species connectivity networks at the landscape level [16].…”