Urban Encroachment on the Wilderness: Moose-Vehicle Collisions in Anchorage, Alaska,

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1 Urban Encroachment on the Wilderness: Moose-Vehicle Collisions in Anchorage, Alaska, Larry C. Garrett and George A. Conway Epidemic Intelligence Service and National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Anchorage, Alaska, USA Abstract: Background: Moose have successfully adapted to urban sprawl in Anchorage, Alaska, using greenbelt areas for shelter, forage, and protection. However, the proximity of moose to people poses unique hazards: a collision with a moose may cause significant injury and vehicle damage. Methods: Moose-vehicle collisions were identified using Municipality of Anchorage records. Completeness of reporting was assessed from Alaska Department of Fish and Game records. Results: The moose-vehicle collision rate increased significantly from 38 to 49.2/100,000/yr during the study period (p ==.005, x 2 = 7.795). Of 519 reported moose-auto collisions, 120 (23%) resulted in injury to 158 people, with no human fatalities. Most collisions (291 or 56%) occurred between 1800 and 0 hours; 411 (79%) occurred after dark; 154 (30%) occurred during December and January; and slick road conditions were identified in 280 (54%) incidents. Incidents occurred primarily near greenbelt areas. Conclusions: Moose-vehicle collisions often occur at night, on unlighted, slick road surfaces. Moose-vehicle collisions may be prevented by: reducing speed limits around green-belt areas, brighter vehicle headlights, placement of street lights in known moose areas, underpasses for wildlife at known crossings, and snow removal to reduce berm height in known moose areas. Keywords: Anchorage; Alaska; Moose-vehicle collisions; Injury prevention; Urban wildlife INTRODUCTION Located on the upper shores of Cook Inlet, Anchorage, Alaska, is truly a city on the edge of the wilderness. To the east of Anchorage is the rugged wilderness of the Chugach Mountains; and to the west is Cook Inlet, with daily tidal fluctuations of 33 feet, the second highest in the world. North of Anchorage, Mt. Mc Kinley can be seen on a clear day. The local population of moose (Alces alces gigas) in the subarctic Anchorage area has adapted well to urban life; however, as the population of Anchorage grows, conflicts between humans and moose have become more common. Although an estimated 450 moose live in ~he Anchorage area year-round, the population is estimated to double in winter, due to the influx of migratory moose. 1 When winter snow accumulation begins to hamper movement and cover forage, moose move down from the mountains through Ship, Campbell, and Rabbit creeks, which funnel moose into the Anchorage area. Snowpack is less and movement is eased by the many roads and trails found within the city. Willows, birches, and aspens 2 found in abundance in the many parks and greenbelt areas of Anchorage sustain the moose throughout the winter. Shelter from winter storms and protection from local populations of predators make the city an attractive environment for moose in the winter. In spring the surviving moose follow the melting snow back into the mountains, only to return the following year. The close proximity of moose to people poses unique hazards: in 1995, a 71-year-old man was trampled to death in front of the University of Alaska Anchorage sports center by a cow protecting her calf.3 Rutting bulls occasionally attack people as well. A motor vehicle colliding with this largest (9 ft. tall lb.) member of the deer family can cause significant injury and vehicle damage. METHODS To characterize moose-auto collisions in Anchorage, information was abstracted from the 96 Circumpolar Health 527

2 Figure l. Methods. Moose-vehicle Incident Reports Municipality of Anchorage, Department of Public Works, Traffic Engineering Division Records (n = 510) Validation with Alaska Department of Fish and Game records Results Municipality of Anchorage, Department of Public Works, Traffic Engineering Division records. Completeness of reporting was assessed by records obtained from the Alaska Department of Fish and Game (ADF&G) (Figure 1). A total of 519 records was reviewed for the years RESULTS The moose-vehicle collision rate in the Anchorage area increased during the five-year study period from 38/ l 00,000/yr in 1991 to 49/ 100,000/yr in an increase of 23% (Figure 2). Trend analysis showed this to be a significant increase (p =.005, x 2 = ). There were 519 moose-vehicle collisions, and injuries to vehicle occupants occurred in 23% (n = 120) of these incidents, injuring 158 people (range 1-4 ). There were no fatalities. The time of day moose-vehicle collisions occurred had a bimodal distribution: over half ; Figure 2. Number and rate of moose-auto collisions in Anchorage, Alaska, : by year Total collisions Injury collisions Total persons injured Collision rate jcocl (rate/i 00,000 residents/yr x 2 = p =.005) (n = 291, 56%) of the collisions occurred in an eight-hour period between 18:00 and 01:59; a smaller peak (three hours) occurred between 06:00 and 08:59 (n = 86, 17%) (see Figure 3). The most frequent hour cited for all collisions was between 21:00 and21:59 (n= 45, 9%); there were no incidents between 13:00 and 13:59. Injury collisions were most frequent between 20:00 and 23:59 (n = 48, 40%). Collisions were four times more likely to have occurred in the dark (n = 411, 79%) than during daylight (see Figure 4); 61 % (n = 252) of the collisions that happened in the dark occurred on unlit road surfaces-that is, there were no street lights in the vicinity of the incident. Seventy-eight percent (n = 94) of the injury collisions occurred in the dark; of those, 65% (n = 61) occurred on an unlit road surface. The months with the least amount of sunlight (December and January) were the most frequently cited for a collision to occur (n = 154, 30%) (see Figure 5). September and October were most frequently cited for an injury collision (n = 35, 29%). However, 38% (n = 13) of the collisions that occurred in February resulted in an injury, the highest month cited; December was the lowest with 10% (n = 7). Cloudy weather was the most frequently cited weather condition, accounting for 52% (n = 269) of all moose-vehicle collisions and 50% (n = 60) of the injury incidents. Periods of reduced visibility-rain, snow, fog, and other conditions-accounted for only 18% (n = 95) of all collisions and for 16% (n = 19) of the injury incidents (see Figure 6). Slick road conditions-wet, snow, slush, and other conditions-accounted for 54% (n = 280) of all moose-auto collisions during the study period (see Figure 7). However, only 41% (n = 49) of the injury incidents occurred on slick roads. A moose-auto collision on a dry road was two times ( l.29<odds ratio<3.08, p =.001) more likely to result in an injury as an incident on a slick road. A spot map was constructed using moose-ve Circumpolar Health

3 CDC : Figure 3. Moose-auto collisions in Anchorage. Alaska. l : time of occuitencc. -~!OCk ~ ~~~rrnjury ii'lc 47< Morning I n c c c c c c :!.. ~ ~ :----i ::.:: 'C ~ ~ ::::0 c c c c c c :::: ,...,.,.., ~ '~ "" ~~ ~" :..,,?' :'-' J: 'C... N ~ 6 6 ~ 6 ~ :::: ::::0 ~ 6 c ::::0 c c c c c c c c c c Time 1Vight hicle collision data for the years Major east-west commuter roads from Hillside neighborhoods and areas adjacent to greenbelt ;nd park areas were identified as places of increased risk for moose-vehicle collisions. Injury collisi0ns occurred more frequently in areas with higher speed limits. There was substantial underreporting of moose-vehicle incidents in the Anchora e area. ADF&G reported 648 moose killed b;~ motor vehicles in the Anchorage area during the stud; period: only 519 i807c) were recorded by the Municipality of Anchorage. DISCUSSION Throughout Alaska. 20Clc of all moose-auto collisions result in injury and 0.5'1l:- result in a human fatality. 4 Extrapolating. one would expect to see three such human fatalities and 104 injuries in Anchorage during the study period. Figure 4. Number of moose-auto collisions in Anchorage. Alaska : light conditions. [Qg 3UO I 50 I 011 i I lnjurv ( D So11-i11j111T Figure 5. Number of moose-auto collisions in Anchorage. Alaska : by month. JOO,---;=:====~------, 80 (if).w ! I lnjun, i 0 So11-111j11n Dm /ight Twilight Durk/Light Dark F.H A Jf J J A S 0 \" D Jan. J!onth 96 Circumpolar Health 529

4 Figure 6. Number of moose-auto collisions in Anchorage, Alaska : weather conditions ! I Injury D Non-injur; 0 Clear Clo.tdv Rain Snow i ogl Other lcocl Smoke Figure 7. Number of moose-auto collisions in Anchorage, Alaska, : road conditions JOO 50 0 I lnjurv D Non-injurv Drv Wet Snow Slush Other [I?9. As reported. there were no fatalities during the study period and 120 injury incidents. The lack of fatalities in Anchorage suggests overall speeds at the time of collision are lower than those on rural highways. The IO<k (n = 16) excess of injury collisions may be due to decreased s.:."t-belt use and increased vehicle occupancy rates of urban drivers: this is an area that requires further investigation. The direct cost (medical care and vehicle repair/replacement) associated with moose-vehicle collisions in Anchorage is $ ( U.S.J. based on the estimated cost per collision of S To reduce the high number of injuries and the costs associated with a moose- 6 vehicle collision. preventive measures need to be implemented. The reduction of speed limits in areas adjacent to parks and greenbelts, as well as in highrisk areas including the east-west Hillside commuter routes, warrants consideration. Visibility, or the ability of the driver to see moose, is a factor in nearly all collisions. During the winter months, daylight hours are reduced and much of the driving is done on dark, unlighted streets. Increasing visibility by upgrading the headlights of older vehicles with halogen bulbs and keeping headlight lenses clean are inexpensive ways to decrease the number of moose-vehicle collisions. The placement of street lights in known moose areas could also increase visibility. Fencing and the redirection of wildlife through underpasses are site-specific solutions that could be implemented in areas known for high moose-vehicle collision rates. In the early 1980s, the Glenn Highway between Anchorage and Eagle River had the highest rate of moosevehicle collisions in Alaska. During the three years subsequent to fencing and lighting a 3.3- mile stretch, moose-vehicle collisions declined by 95%. 5 Fencing, however, is expensive and not an option in all areas. The reduction of snow-berm heights along plowed roadways is another option to reduce moose-vehicle collisions. With reduced berm heights, drivers would be better able to see moose in the area. Anchorage currently pushes snow back off the road at an estimated cost of $500 per mile; to push it back, scrape it up, blow it into trucks, and haul it to a snow dump would cost $2500 per mile. 6 Due to these costs. snowberm removal is impossible on all streets; however, it should be done in areas known for high rates of moose-vehicle collisions. Most moose-vehicle collisions occur at night, on unlighted. slick road surfaces. The inability of drivers to see moose is a factor in nearly all incidents. Moose-vehicle collisions may be prevented by: reducing speed limib around greenbelt areas. brighter vehicle headlights. placement of street lights in known moose areas, fencing and underpasses for wildlife at known crossings, and snow removal to reduce berm height in known moose areas Circumpolar Health

5 The proximity of moose to people in the Anchorage area is a growing concern. With proper identification of problem areas and implementation of safeguards, moose and humans can reside side by side in Anchorage. REFERENCES 1. Alaska Department of Fish and Game. Moose management in the Anchorage management area. Anchorage, AK: Division of Wildlife Conservation, Alaska Department of Fish and Game, Alaska Department of Fish and Game. Wildlife notebook series: moose. Anchorage, AK: Division of Wildlife Conservation, Alaska Department of Fish and Game, Enge M. A deadly winter for moose: weather, traffic take a heavy toll. Anchorage Daily News. March 20, Page B Thomas SE. Moose-vehicle accidents on Alaska's rural highways. Anchorage, AK: Division of Design and Construction, Central Region, Alaska Department of Transportation and Public Facilities, McDonald MG. Moose movement and mortality associated with the Glenn Highway expansion, Anchorage, Alaska. A lees. 1991; 27 : Freedman D, Withey D. Fenced in. Anchorage Daily News. May 18, Page HI. Correspondence: Larry C. Garrett Centers for Disease Control and Prevention NIOSH. Division of Safety Research Alaska Field Station Grace Hall, Suite University Drive Anchorage, Alaska USA 96 Circumpolar Health 531