'Tis the season: Colorado wildlife is on the move. Animals are migrating to wintering habitats, which is the reason this season - particularly October and November - tends to have the highest incidents of wildlife-vehicle collisions.
Wildlife-vehicle collisions happen year round, all day, every day. However, there is always an increase during migration season, particularly during the 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 collisions will vary among highways, areas and regions, and also year by year. Often, however, overall trends can be seen when multi-year data is examined.
"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 and Safety Engineer Mike McVaugh. "Only then can we make good decisions."
Data for the period between 1999 and 2011 shows various trends, the 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 said. "It could be due to weather, changing migration routes, a number of things. We hope that some of our wildlife mitigation efforts, as well as changes in driver behavior, have had a positive impact over the years."
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) 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. In these zones, CDOT reduced speeds to 55 mph only where current speeds are posted at 60 or 65 mph, and only during migration season, now set for October through May. 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 that during the study period, which included two full migration seasons between April 2010 and May 2012, there was a slight decrease in wildlife-vehicle collisions overall within the "Wildlife Zones" in the two-year period when 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 variations among these data 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; though it is difficult to conclude without a speed study that an overall drop in WVCs was a result of a drop in drivers' speeds.
CDOT 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, CDOT 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 and Safety Engineer Zane Znamenacek said. "Also, the preliminary data led us to change the enforcement period and signage to Oct. 1 through June 1 (from the original Sept. 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 is working to reduce collisions.
While the legislation asks CDOT to set nighttime regulatory speed signs, actually designating those nighttime hours throughout the season is a bit challenging. Per the signs, speed enforcement is set from 5 p.m. to 7 a.m. - 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," Znamenacek explains. "While it's not fully dark at 5 p.m. yet, please remember that this is a safety education initiative - wildlife are moving, day and night. Slow down, drive aware and give yourself a better chance of avoiding a collision. Enforcement or not, it's just makes good, safe sense this time of year."