Study considers impact of wildlife warning reflectors

Study determining effects of wildlife warning reflectors on wildlife-vehicle collisions moves to Big Horn County

The Wyoming Department of Transportation and Conservation Research Center of Teton Science Schools are continuing a three-year study this fall and winter to evaluate the effects of wildlife warning reflectors on wildlife-vehicle collisions in Big Horn and Fremont counties.

This fall and winter’s study is limited to the areas between Basin and Greybull on U.S. 16/20, and west of Riverton on U.S. 26.

Part of the study involves covering wildlife warning reflectors with bags to study deer behavior with and without the reflectors working as they are intended.

“The researchers are studying the reflector installations about one mile at a time at night — both with the reflectors uncovered and with the reflectors covered with white canvas bags,” according to Cody Beers, WYDOT public relations specialist in Riverton.

Field research on the three-year study is occurring this fall and winter in Big Horn and Fremont counties. The Teton Science Schools research team will be parking near the highway this fall and winter to conduct its research.

In 2007, WYDOT began installing wildlife warning reflectors (deer delineators) throughout Big Horn, Hot Springs and Fremont counties. Between 2007 and 2010, wildlife warning reflectors were installed west of Riverton on 4.7 miles of U.S. 26 between Kinnear and Riverton, and just north of Kinnear; on six miles of U.S. 16/20 between Greybull and Basin; on 3.3 miles of U.S. 20 between Wind River Canyon and Thermopolis; and on 8.9 miles of U.S. 20 between Thermopolis and Lucerne.

“More than 75,000 wildlife-vehicle collisions have been recorded in Wyoming during the past two decades, and of these, 7,500 have occurred within a 60-mile buffer of Thermopolis,” said Morgan Graham, Conservation Research Center Geographic Information Systems manager and principal investigator of the study.

More than 17 million vehicle miles driven are recorded daily in Wyoming, and Fremont, Big Horn and Hot Springs counties rank seventh, 18th and 23rd, respectively, as counties with the most daily vehicle miles driven. But Big Horn, Hot Springs and Fremont counties also rank first, third and sixth, respectively, in the most wildlife-vehicle collisions per vehicle mile driven in Wyoming.

Graham said the study will determine the effect of the wildlife warning reflectors on the wildlife-vehicle collision rate; will quantify factors that influence wildlife-vehicle collisions; and will examine the effects of wildlife warning reflectors on deer highway crossing patterns and behaviors.

“A properly installed modern wildlife warning reflector system consists of a series of roadside posts with unique reflectors mounted to face across the roadway,” Graham said. “As vehicles pass with headlights on, light is reflected in a moving pattern across the road at various angles. Approaching wildlife will notice the reflected light, causing them to halt until the vehicle and lights have passed.”

The manufacturer of the reflector system (Strieter Corp.) reports a 78 to 90 percent reduction in deer-vehicle collisions, but results of independent studies have varied on systems installed throughout the United States.

“Current information does not provide a definitive conclusion on whether modern deer delineators are effective, nor is it clear if they influence deer behavior,” Graham said. “Our study will provide much-needed data on deer delineator efficacy as a wildlife-vehicle collision mitigation tool. It will address the effect of deer delineators on roadside deer behavior, and it will develop an understanding of deer road crossing selection.”

Graham said results of the study should help WYDOT make future “informed decisions regarding transportation planning, roadway improvements and mitigation recommendations.”