Underreporting

Underreporting of Wildlife Collisions on Northern BC Highways

How do we know how many wildlife vehicle collisions (WVCs) occur? In BC, as in most other jurisdictions, the number of WVCs that are recorded in official databases is likely not the actual number that have occurred. Reasons for underreporting of WVC numbers include:  

• the carcass is removed by others prior to collection by officials 
• the animal is hit but not killed and moves away from the road so that the carcass cannot be recovered
• the collision is not reported to ICBC or attended by police

Quantifying Underreporting

The Wildlife Collision Prevention Program completed an analysis of WVC data on select northern BC highways to understand the underreporting issue better. The primary concern about WVC underreporting is that any conclusions drawn about WVCs, and the environmental and engineering factors associated with them, are based on a substantially incomplete dataset, and therefore, subject to error.

In BC, the two main agencies that collect information on WVCs are the BC Ministry of Transportation and Infrastructure and the Insurance Corporation of British Columbia. Less complete data about WVCs are also collected by the BC Conservation Officer Service and the RCMP. 

WCPP compared WVC data from these four different agencies to establish a baseline number of WVCs on northern BC highways. This data was then used to document patterns in WVC underreporting and establish the degree of underreporting by agency.

Wildlife vehicle collision data from collisions with large mammals (deer, moose, bear, elk, and caribou) occurring on select highways in northern BC were used in this project. Data from January 1, 2004 to November 30, 2013 were obtained from BC MOTI through the highways maintenance contractors (carcass counts), ICBC (claimant collision reports), RCMP (police-attended collision reports), and the Conservation Officer Service (incident reports of injured or dead wildlife on the roadside). 

Reports

Quantifying wildlife vehicle collision underreporting on Highway 33 (2008 - 2017)

Quantifying wildlife vehicle collision underreporting on northern British Columbia highways (2004 - 2013)

Highlights:

• Averaged over all project highways, BC MOTI captured 34.3% of the known number of WVCs that occurred (an underreporting rate of 65.7%). This supports BC MOTI's stated operating assumption that between 25% and 35% of the actual number of WVCs are captured by their maintenance contractors.
• Averaged over all project highways, ICBC captured 45.5% of the known number of WVCs that occurred (an underreporting rate of 54.5%).
• The Conservation Officer Service was notified of 10.0% of the known number of WVCs (an underreporting rate of 90.0%).
• The RCMP attended 10.2% of the known number of WVCs (an underreporting rate of 89.8%).
• BC MOTI and ICBC databases captured very similar proportions of species-specific WVCs. This differs from the Conservation Officer Service who captured significantly different proportions of WVCs by species than either BC MOTI or ICBC.
• The results showed that BC MOTI (carcass count) underreporting of 65.7% and ICBC (collision report) underreporting of 54.5% fit into the mid-range of underreporting documented in other jurisdictions across Canada, the USA, and internationally.