Wildlife vs. Vehicle Costs Top $225 Million Annually in California

More Funding Needed for Prevention Efforts, Road Ecology Center Advises

Quick Summary

  • Wildlife vs. vehicle costs equal about 2 percent of California’s transportation budget
  • Nearly 6,000 California traffic accidents in 2015 involved wildlife
  • Report aims to help governments safeguard people and wildlife

Editor's note: This version corrects links for the interactive map and 2016 report, and adds I-280 to the list of San Francisco Bay Area hot spots.  

Collisions involving vehicles and wildlife along California’s highways cost more than $225 million annually, according to a new UC Davis study that uses traffic-incident reports to identify hot spots of concern for both public safety and wildlife conservation.

Data from state data sources indicated there were about 560,000 traffic incidents from February 2015 to February 2016, about half of which were collisions. Of these, 5,950 involved wildlife.

Map of California with colorful dots showing costs of highway collisions between vehicles and wildlife
Costs of collisions between vehicles and wildlife on California highways. (Courtesy/UC Davis Road Ecology Center)

A database of these wildlife vs. vehicle events was developed primarily from incident reports prepared by the California Highway Patrol and other emergency responders.

This cost analysis is the second group of findings from the 2016 report by the UC Davis Road Ecology Center, which in June identified roadkill hot spots throughout California. The roadkill report drew largely from the thousands of volunteer scientist observations submitted into the California Roadkill Observation System,

The 2016 report pinpoints stretches of highway where wildlife-vehicle conflicts occurred in 2015. These cases involved animals running across the road, vehicles colliding with wildlife, or accidents that occurred when people swerved to avoid hitting wildlife. The researchers estimate that as many as 50,000 deer are hit by vehicles annually in the state.

“By identifying the cost and locations of these conflicts, we hope to help state and local government entities better protect wildlife and drivers from collisions,” said Fraser Shilling, co-director of the UC Davis Road Ecology Center and director of the California Roadkill Observation System.

“Since the cost of wildlife-vehicle conflict equals about 2 percent of California’s transportation budget, it would seem reasonable to earmark 2 percent of that budget for efforts aimed at preventing incidents that threaten the safety of both animals and people,” he said.

Interactive map shows wildlife vs. vehicle hot spots

An interactive map shows locations of incidents involving wildlife throughout the state, for the fall, when collisions are more likely to occur.

Hot spots illustrated by the report were identified in:

  • Southern California along state routes 33, 60, 134, 2, 18, 74, 52 and 67
  • The San Francisco Bay Area along U.S. 101 in the North Bay, state routes 17 and 24, and interstates 280, 680 and 580 (Better fencing along these roadways could encourage wildlife to use existing culverts and bridges for safe crossings.)
  • The Sierra Nevada foothills along U.S. 50, state routes 49 and 20, and I-80 east of Sacramento, and especially for wildlife to the south along state routes 88, 108 and 41 as these highways climb into the foothills from the Central Valley
  • The desert and Sierra Nevada, primarily along U.S. 395, especially from Bridgeport south to the intersection with U.S. 6
  • The northern mountains, including the northern Sierra Nevada, Modoc Plateau and Mt. Shasta regions along state routes 70 and 89 (Plumas County), along U.S. 395 near Susanville and along I-5 just north of Redding and near the Oregon border
  • The North Coast along U.S. 101/state Route 1 from the North San Francisco Bay Area to the Oregon border, in Northern Napa and Lake counties along state Route 29, and in Lake County along state Route 20 east of Clear Lake
  • The Central Coast along U.S. 101 from the South San Francisco Bay Area to Santa Barbara, (with fewer incidents near Salinas), and in the Monterey Bay area, San Luis Obispo and the Lompoc/Solvang region along state routes 1, 68, 46 and 166

Media Resources

Fraser Shilling, UC Davis Road Ecology Center, 530-219-3282, fmshilling@ucdavis.edu

Pat Bailey, UC Davis News and Media Relations, 530-219-9640, pjbailey@ucdavis.edu

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