odot wildlife hotspots study results of statewide analysis july 21, 2008 melinda trask oregon...
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ODOT Wildlife Hotspots Study
RESULTS OF STATEWIDE RESULTS OF STATEWIDE ANALYSISANALYSISJuly 21, 2008July 21, 2008
Melinda Trask Oregon Department of Transportation, Geo-Environmental Section, Salem ORFrancesca Cafferata-Coe, Jessica Burton, Ellen Voth, and John Lloyd, Mason, Bruce & Girard, Inc., Portland OR
Types of Wildlife Collision Data Focused Road Kill Observations
Possible to get accurate location and species info. Most expensive
Expert Opinion Good for first cut; precursor to focused studies Subjective; not empirical
Crash Records Used for national statistics Limited subjective reporting Data quality cannot be verified
Dispatch Carcass Reports Most comprehensive option Data quality cannot be verified
Oregon's Highway Animal-Vehicle Collisions
CRASH RECORDS: Avg. 400 wildlife collisions per year, past 14 years
About 5,500 records statewide Less than 3% of all crash reports in Oregon 15 fatalities & 117 serious injuries in 14 years
Crash records represent only a small portion of actual animal-vehicle collisions nationally (less than 10% of actual; literature)
Dispatch Carcass Records 6 times more data in similar period Represents avg. 2,600 wildlife collisions
per year, past 12 years About 32,000 records statewide in OR
(12 years)
ODOT Wildlife Collision Prevention Plan Addressing wildlife passage is supported by the Governor and
ODOT’s current mission and goals, and particularly within the values of safety, accountability, and environmental stewardship.
Current lack of information - we cannot adequately address the problem. Do we have a significant statewide road kill problem or just some
areas? Need to prioritize wildlife movement corridors and highway
barrier problem areas to make science-based decisions and cost-effective, versus ad-hoc.
Need better tools to adequately address wildlife passage. Non-regulated but supported by FHWA, ODFW, USFWS,
CETAS, nationwide attention.
Density:
low
medium
high
ODOT Wildlife Collision Hot Spot Analysis Uses existing carcass pick-up records Statewide, analytical approach Identify high frequency wildlife-vehicle collision zones Conducted pilot study in D10 to fine tune methods and
determine the feasibility of statewide analysis
USHwy
Data Preparation - Methods 3 different types of record keeping Wildlife Incident Reports, call = RDKILL Animal Type, Deer & Elk Consistent Dates, 12 yeas of data (1995-2006) Location, +/- 0.5 mile Link Location to GIS Coordinates
CAD_NUM CALL DATE LOCATION UNIT S
95309256 RDKILL 10191995 5925 WALLACE RD HWY2 1
95309392 RDKILL 10201995 HELMICK ROAD / 99 SR ;12600 HELMICK RD 21A P
95309598 RDKILL 10201995 21.5 228 SR 3A20 P
95312278 RDKILL 10231995 5.9 22 SR 3A26 1
95312329 RDKILL 10231995 SHERWOOD @ 99W SR MP 15.2-15.8/ ; 19025 SW PAC HWY 3A52 P
95312331 RDKILL 10231995 HWY 212 / FORMORE CT 4A30 P
Data Preparation - ResultsOriginal # Records 31,595 (100%)
Step 1 - Data Processing Narrowing Acceptable Parameters 25,216 (80%) (20% reduction)
Cut out records older than 1995, duplicate records, non deer/elk, low precision (> 0.5 mi)
Tabular Information Problems 21,335 (68%) (12% reduction) Poor location, highway nomenclature, or MP Not enough information in recorded data MP not referenced
Step 2 - Linkage to GIS GIS Mapping Problems 17,824 (56%)* (11% reduction)
Route ≠ ODOT Highway number
* Final number of "good" records used in data analysis.
GIS Challenges 2 highway numbering systems in use Signed Highways State Highway Routes
(ODOT internal system) Mileposts based on
Routes not signed hwys Mileposts not unique on
signed hwys Dispatch data generally
refer to Routes Final dataset reduced to
only records with equal hwys:route relationship
Final Data SetNumber of Records By Region By Year
Region Year R1 R2 R3 R4 R5 All 1995 16 73 1 0 0 90 1996 32 415 3 0 0 450 1997 33 400 3 0 5 441 1998 30 435 18 60 33 576 1999 33 444 411 336 145 1,369 2000 75 4 466 317 200 1,062 2001 81 5 591 389 317 1,383 2002 56 4 525 394 586 1,565 2003 86 370 675 675 872 2,678 2004 81 315 705 751 1,003 2,855 2005 54 379 866 918 1,094 3,311 2006 67 112 167 621 1,061 2,028 TOTAL 644 2,956 4,431 4,461 5,316 17,808
Nearest Neighbor Analysis 1st cut to see if clustering is non-random
Ripley’s K Distribution Gives indication of scale of clusters
Kernel Density Evaluation Shows location of clusters by density
Analytical Methods
Results: Nearest Neighbor Analysis Carcass reports
occur significantly closer together than would be expected by chance
Does not identify where the clusters occur
REGION R1 R2 R3 R4-5
Confidence Interval 99% 99% 99% 99%
n 100 100 100 100
t 2.63 2.63 2.63 2.63
Expected Mean NN Dist. (ft) 3951 2944 807.1 1201
Standard Deviation (ft) 199.1 77.72 13.75 10.87
Standard Error of the Mean 19.91 7.772 1.375 1.087
CI 1/2 width (ft) 52.28 20.41 3.61 2.86
Lower Confidence Limit (ft) 3899 2923 803.4 1198
Upper Confidence Limit (ft) 4003 2964 810.7 1204
Observed Mean NN Dist.(ft) 3484 2215 490.7 731.9
Nearest Neighbor Index* 0.88 0.75 0.61 0.61
* If <1.0, indicates significant clustering
Results: Ripley’s K Distribution
Looks at a range of scale distances Shows significant clustering of WVCs at all distances Does not identify cluster locations
Ripley's K-Function10 distance bands (d = 1 mile)
0
500
1000
1500
2000
2500
3000
3500
4000
4500
1 2 3 4 5 6 7 8 9 10
Scale distance (d) in miles
K-v
alu
e Observed
Low er CI
Upper CI
Region 3 shown (other Regionsessentially the same)
Results: Kernal Density Evaluation Analogous to a histogram
of reports per unit area with infinitely small bins
Produces an estimate of risk for each point. Highlights highway segments
with higher density probabilities than others
Results Depend on: Density of points Relative proximity of points Study area Method of categorizing Ranking or # “bins”
D
D
DD
D
D
D
D
D
D
D
DD
D
D
D
D
D
D
D
D
D
D
DD
D
D
D
DDD
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D D
D kj
kj
kj
kj
kj
kjkj
kj
kjkj
kj
kjkjkjkj
kjkj
kjkjkj
kj
kj
kjkjkj
kjMedford
Grants Pass
OP
ER
AT
PR
ES
RV
SAFETY0
5
5
0
5
0
5
0
5
0
5
0
55
3510
15
10
20
10
10
70
45
35
60
55
50
40
PRESRV
MODERN
MODERN
MODERN
MODERN
BRIDGEBRIDGE
BRIDGE BRIDGE
BRIDGE
MODERN
SAF-EX
BRIDGE
Highways
Kernel Density Estimate*High Density Low Density
kj stip2008_11_pts_final
stip2008_11_segs_final
D Approx milepoint
Discussion This study did not address why hotspots are found
in these areas. vehicle speed, traffic volume, movement barriers, adjacent
habitat structure, animal distribution, travel corridors, etc. Necessary to make sound management decisions
ODOT can pay for wildlife crossing improvements Justified under PD-04 FHWA Enhancement program (Category 11) Oregon Transportation Plan (Goal 4.1.1) SAFETEA-LU Section 148 (approved uses of safety funds)
Hazard Elimination Program (HEP) Highway Safety Improvement Program (HSIP)
Next Steps ??1. Convert data to vector and link to Hwy/MP
2. Clean-up data for Regions – spreadsheet
3. Uses in Planning
4. Uses in Project Development
5. Uses in Safety Projects??
RESEARCH NEEDS Detailed case-studies Design Options Characterize existing highway crossings and barriers
Wildlife Connections Conference