7 Large Animal Crash Mitigation
7.1.2 Flashing Light Animal Sensing Host (FLASH), Nugget Canyon - Wyoming17
Impetus for the Activity
As many as 600 mule deer are killed in this area each year. Additionally, some elk, pronghorn (antelope) and moose cross in this area.
System Description
The system is located on US Highway 30 between Cokeville and Kemmerer. This area is a heavy migration path for mule deer between winter and summer ranges. 11 km of deer-proof fence with three openings were installed in 1989 to help mitigate this problem. The fence opening at this site is approximately 120 m. Union Pacific Railroad runs parallel to the highway also causing high deer mortality.
The system consists of two types of detectors: (1) two passive infrared radar sensors (together with the flashing sign known as FLASH), and (2) ten buried geophone sensors (Eagle Telonics) detecting ground vibrations. Highway advisory radio plays a short 30-second message about the crossing zone and why drivers should slow down.
The system was installed on October 1, 1998.
System Effectiveness Evaluation
Speed reductions have been observed when the sign was flashing. Speed reduction was higher for passenger cars than trucks. These speeds were measured by microwave radar units placed at the beginning of the study area and at the center of the crossing zone.
Obstacles and Lessons Learned
False detections were a large problem initially. There was difficulty in finding the optimal setting for sensitivity of the geophones. If they were too sensitive, vehicle and train vibrations were detected. However, if the geophones were not sensitive enough, they would not detect animal presence.