University of California, Davis: Annual ‘Roadkill’ Report Identifies Hot Spots and Paths Forward
In the past five years, collisions between wildlife and vehicles cost California at least $1 billion and potentially up to $2 billion, according to estimates in an annual report by the Road Ecology Center at the University of California, Davis.
The report presents an overview of collisions with large and small animals — from bighorn sheep, deer and bears to squirrels, birds and lizards. The Road Ecology Center mapped about 15,000 miles of state highways to identify stretches of highway where wildlife-vehicle collisions, or WVCs, are most likely to occur.
It names Interstate 280 as the “Deadliest Highway in California” for WVCs. This interstate on the San Francisco Peninsula runs between San Bruno and Cupertino. Five of the top-20 costliest segments are on I-280, costing the state around $178,439 per mile per year.
“These findings illustrate the tip of the iceberg of ecological and economic impacts that wildlife-vehicle collisions cause for California,” said lead author Fraser Shilling, director of the Road Ecology Center. “We need the Legislature to step in and help the good folks in transportation to fence the conflict hot spots and build many more wildlife crossings.”
Hot spots
The report is based on more than 44,000 California Highway Patrol traffic incidents involving large wildlife and more than 65,000 observations reported to the web app California Roadkill Observation System, or CROS, between 2009 and 2020. Anyone in California can collect roadkill data using the app.
In addition to I-280, key hot spots include:
San Francisco Bay Area: U.S. 101 through southern Marin County; I-680, I-80, state Route 24 and SR 13 through the East Bay; and SR 17 near Lexington Reservoir
Sacramento-Placerville Area: I-80, U.S. 50 and SR 49 in the Sierra Nevada foothills
Central Sierra Nevada: SR 4, SR 41, SR 88, SR 108, and U.S. 395
Northernmost region: I-5 between Lake Shasta and the Oregon border, SR 44 in Lassen County, U.S. 101 along the North Coast, and SR 20 near Clear Lake
Southern California: I-405 and SR 2 in Los Angeles County; I-15, SR 67, I-8 in San Diego County; U.S. 101 and SR 154 in Santa Barbara County.