Wildlife On The Move!

By Nancy Shanks, Public Relations, Colorado Department of Transportation

Nearly nine months out of every year, Colorado’s wildlife are on the move. And as wildlife migrate to and from winter habitats in the fall and spring, they are crossing roadways. These migrations periods—and the month of November in particular—result in the highest incidents of wildlife-vehicle collisions (WVCs).

While WVCs spike during migration season, there is also an increase in incidents during dark hours, between dusk and dawn. These collisions are not only a matter of safety, but can be quite costly as well.

According to Carole Walker, executive director of the Rocky Mountain Insurance Information Association, the insurance industry pays out nearly $1.1 billion a year in claims for all wildlife-vehicle collisions nationwide—and the cost to pay those claims is rising.  The average property damage cost of collisions involving wildlife during the final half of 2010 and the first half of 2011 was $3,171, up 2.2 percent from the year before.

WILDLIFE-VEHICLE COLLISION TREND – Wildlife-vehicle collisions (WVC) will vary among highways, areas and regions, and also year by year. Oftentimes, however, overall trends can be seen when multiple years of data are analyzed.

“When we plan or implement any kind of wildlife mitigation for our roadways, we always look at data over a 5 to 10-year period,” said CDOT Region 5 Traffic & Safety Engineer Mike McVaugh. “Several years of data help us to make the right decisions to help reduce the wildlife accident potential.”

Data for the period between 1999 and 2011 (please see link at the bottom of this article) show various trends, most notable being that WVCs have been on a bit of a downward trend since 2006.

“Even though the number of hits varies among counties and certainly among roadways, this overall trend is encouraging,” McVaugh says. “It could be due to weather, changing migration routes, or the increased emphasis CDOT has made to warn and inform motorists. We hope that our wildlife mitigation efforts, as well as changes in driver behavior, have had a positive impact over the years.”

WILDLIFE ZONES LEGISLATION – SIGNING CONTINUES – This year, motorists will continue to see roadside reminders to slow down in specifically designated corridors. Legislation, sponsored by Representative Kathleen Curry and Senator Gail Schwartz (and several non-governmental organizations, listed below) in 2010 called for lowered nighttime speeds and doubled fines for speeding at night in designated “wildlife crossing zones.” (There are no fines for hitting an animal.)

Per the HB 1238, the Colorado Department of Transportation identified 100 miles of wildlife crossing zones where nighttime speed enforcement was feasible. CDOT set signs within the zones (see zone chart, below):  nighttime speeds are reduced to 55 mph only where current speeds are posted at 60 or 65 mph, and only during migration season, now set for October 1st through June 1st. Other sections of highway are signed “WILDLIFE CORRIDOR” but the nighttime speed remains the same—fines are doubled for speeding in all the zones, however.

Per the bill, CDOT collected data and reported back to the Legislature on results of this pilot initiative in September. The findings indicate the following:

Study Findings:  The data over the study period, which has included two full migration seasons between April 2010 and May 2012, show a slight decrease in Wildlife-Vehicle Collisions (WVC) overall within the “Wildlife Zones” in the two-year period the signs were posted, as compared with the two-year period before signs were posted. Specifically, a 9 percent decrease in WVCs is noted overall. However, there are many variables among these data sets when looking at each individual Wildlife Zone.

There was an overall increase in citations written for speeding in Wildlife Zones (as compared with the previous two years) in these highway segments; this makes it is difficult to conclude if an overall drop in WVCs was a result of increased speed enforcement or driver behavior changing due to the wildlife zone and nighttime speed zone signing program.

Study Recommendation:  The Colorado Department of Transportation has recommended the Wildlife Zones study—per the legislation—be continued over two more migration seasons to gather additional data that could lend to a more conclusive study. In addition, the Department will supplement these WVC and citation data with day- and nighttime speed studies on select Wildlife Zone corridors.

“This series of speed studies will help validate whether there is an actual change in driver behavior,” CDOT Region 3 Traffic & Safety Engineer Zane Znamenacek said. “Also, the preliminary data led us to change the enforcement period and signage to October 1 through June 1 (from the original September 1 to May 1 time period).

At the end of this second two-year study period, CDOT will submit a final report to the Legislature in August 2014, indicating whether or not this signing and enforcement program has worked to reduce collisions.

While the legislation asks CDOT to set nighttime regulatory speed limits, actually designating those nighttime hours throughout the season was somewhat challenging. Per the signs, speed enforcement occurs from 5 PM to 7 AM—these are dark hours in the winter, but not necessarily in the fall and spring. This may leave some motorists questioning the enforcement.

Static enforcement signs must cover the entire migration season. While it’s not fully dark at 5 p.m. yet, CDOT reminds motorists that this legislation presents a safety education initiative—wildlife are moving, day and night. Motorists are asked to slow down, drive aware, and give themselves a better chance of avoiding a collision.

Non-Governmental Organization & Individual Wildlife Bill Sponsors:

Monique DiGiorgio, Common Ground Conservation
Paige Singer, Conservation Biologist, Rocky Mountain Wild
Caitlin Balch-Burnett, Defenders of Wildlife
Frosty Merriott, Trustee – Town of Carbondale
Suzanne O’Neil – Colorado Wildlife Federation, E.D.

Link to CDOT’s Wildlife on the Move web page:  http://www.coloradodot.info/programs/environmental/wildlife/wildlifeonthemove

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