7 Large Animal Crash Mitigation
7.1 Roadside Detection and Warning Systems
7.1.1 Active Animal-Vehicle Collision Mitigation System, Colville - Washington16
Impetus for the Activity
WSDOT has been maintaining large mammal roadkill data since 1976, through the maintenance division by way of carcass counts. The Research Office wanted to try some “active” mitigation measures, rather than the passive systems that were being pushed by vendors, such as fencing and reflectors. This area has had a high frequency of animal-vehicle collisions and was perceived as a good area to test such a system. Common animals in the area include whitetail deer, blacktail deer, mule deer and elk.
System Description
The system is located north of Spokane, on US Highway 395 and south of Colville near Chelelah, WA. The area can be characterized by open arid traditional Ponderosa pine forest-grassland zone, with moderate/abundant medium shrubs. The area is 0.4 km in length with a clear line-of-sight.
The system consists of a two lasers (one on each side of the road), two standard deer warning signs—supplemented with a smaller square sign that reads “When Flashing” and a solar powered red strobe. The laser beam activates the dynamic warning sign when broken. Each of the lasers has a data logger coupled with it, which logs “hits” from the system. The system is a “hobo” unit – the lasers operate on batteries (life = 1 week), while the red strobes are solar powered. There are no cameras on the site.
The system was installed June 20, 2000. The lasers cost between $5,000 to 6,000, and the solar units cost between $2,000 to $3,000. Additional expense is required for signage, batteries and maintenance. The system was designed through sub-contracting with an electrical engineer and manufactured in-house at the WSDOT Research Office in Olympia, WA from over the counter parts.
System Effectiveness Evaluation
System effectiveness is to be determined.
Obstacles Encountered and Lessons Learned
Obstacles encountered included:
- Sighting. Clear line-of-sight and sighting the lasers were a concern from the beginning. In anticipation of concerns such as this, an area with clear line-of-sight was chosen. Sighting the laser proved more difficult. It appears that there is direct distortion of the system from sunlight shining on the laser itself. Not only does it throw the sighting of the laser off, but it can also cause false positive readings.
- Theft. The system has experienced some theft of the solar-power units.