Road Ecology:What Do We Know?

Marcel P. Huijser, PhD

Courtesy of MDT, CSKT &WTI-MSU

Human Safety

100000

200000

300000

400000

500000

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

# A

VCs

2000000

4000000

6000000

8000000

# ALL C

RA

SHES

AVCs All Crashes

Huijser et al., 2008

1-2 million large mammal-vehicle collisions/yr

Human injuries: N ~ 29,000/yr

Human fatalities: N ~211/yr

Ecological Impacts Roads and Traffic

12

3

3

4

4

5

5

1. Loss of wildlife habitat

2. Road mortality

3. Barrier effect

4. Decrease in habitat quality (disturbance, pollution)

5. Ecological function of verges

Habitat

Mitigate

Habitat

Compensate

Mitigate

Avoid

Human safety Biological

conservation65%35%

7% 93%

Departure Point Matters!

Hwy 2, Montana (Huijser & Begley, 2016)

Other speciesOther habitatOther effectsOther measures

Population N=1000

Population N=50

Collision reduction for human safety vs.

Mortality reduction for conservation

† N=100 † N=10

… But we mostly focus on: human safety / reducing collisions

• Simple• Inexpensive• Fast implementation• Implementation over long distances

• Warning signs• Vehicle speed reduction

“We” Want ….

Wildlife Warning Signs

• Standard

• Enhanced

• Temporary

• Animal detection system

Huijser et al., 2015

Reduce Posted Speed Limit

• Design speed Lane and shoulder width, curvature, sight distance

• Posted speed limit Legal speed limit depicted on signs

• Operating speed The speed that drivers actually drive

10

Design speed = Posted speed limitGood practice

Design speed ≠ Posted speed limitSpeed dispersion, increase in crashes

11

Reduce Posted Speed Limit

Stopping Distance –Maximum Vehicle Speed

Stopping distance =

Reaction time (distance)+Braking distance

• Reducing speed typically not suitable for highways

• Perhaps suitable for park roads

Huijser et al., 2017

Reduce Collisions: Effective Measures

Standard “ungulate” fence Animal detection systems© Marcel Huijser

Multi-species approach

Collision Reduction

Under- and overpasses needed, especially at higher traffic volumes

Dodd et al. 2007

Crossing Structure Types and Dimensions

Overpass50-70 m wide

Over span bridge>30 m wide>4-5 m high

Large mammal Underpass7 m wide4-5 m high

Medium mammal Underpass1.5-2 m diameter

Small-medium Mammal pipe30-60 cm diameter

© Marcel Huijser

© Marcel Huijser

© Marcel Huijser

© Marcel Huijser

© Marcel Huijser

© Marcel Huijser

Species specific design

Huijser et al. 2008

29 Structures, 5 years• 95,274 successful crossings• 22,648 per year• 20 wild medium-large mammal species

• 1,531 black bear• 958 coyote• 568 bobcat• 227 mountain lion• 29 grizzly bear• 38 badger• 32 elk• 14 beaver• 13 otter• 3 moose

Courtesy of MDT, CSKT & WTI-MSUHuijser et al. 2016

Chart1

White-tailed deer (Odocoileus virginianus)White-tailed deer (Odocoileus virginianus)

Mule deer (Odocoileus hemionus)Mule deer (Odocoileus hemionus)

Domesticated dog (Canis lupus familiaris)Domesticated dog (Canis lupus familiaris)

Domesticated cat (Felis catus)Domesticated cat (Felis catus)

OtherOther

65909

69.18

5365

5.63

5258

5.52

4523

4.75

14219

14.91

Sheet1

Successful crossings (N)

All structuresEvaroRavalli CurvesRavalli HillIsolated

29 structures6 structures9 structures2 structures12 structures

5 yrs3 yrs3 yrs4.5 yrs

SpeciesN%2011-20152010-20122010-20122011-2015White-tailed deer (Odocoileus virginianus)6590969.18

Mule deer (Odocoileus hemionus)53655.63

White-tailed deer (Odocoileus virginianus)6590969.1823870867720733155Domesticated dog (Canis lupus familiaris)52585.52

Mule deer (Odocoileus hemionus)53655.6338217322592659Domesticated cat (Felis catus)45234.75

Domesticated dog (Canis lupus familiaris)52585.5226210704889Other1421914.91

Domesticated cat (Felis catus)45234.75127227862967

Human data collector23512.478037292365839527499.99

Raccoon (Procyon lotor)18971.99124374141385

Human17691.86293414129933

Black bear (Ursus americanus)15351.61605458202270

Birds (Aves)14281.565239172565

Coyote (Canis latrans)9581.01134485127212

Deer spp. (Odocoileus spp.)8540.9706785056

Red fox (Vulpes vulpes)6950.73621686

Western striped skunk (Mephitis mephitis)5720.61711026419

Bobcat (Lynx rufus)5680.614923615726

Human and dog4280.45132960119

Rabbits and hares (Lagomorpha)2610.27318435111

Mountain lion (Felis concolor)2270.2458698713

Other1880.22015630

Cattle (Bos taurus)1190.12660053

Human and ATV700.0730067

Unknown560.0657242

Human and bicycle430.0580035

American badger (Taxidea taxus)380.04042311

Grizzly bear (Ursus arctos)290.0300128

Elk (Cervus canadensis)320.0330020

Bear spp (Ursus spp.)160.0211032

North American beaver (Castor canadensis)140.0101400

Northern river otter (Lontra canadensis)130.011804

Human and horse100.0100010

American mink (Mustela vison)90.010009

Dom. dog or coyote90.011332

Yellow-bellied marmot (Marmota flaviventris)70.010304

Human and car400103

Porcupine (Erethizon dorsatum)400004

Moose (Alces americanus)303000

Long-tailed weasel (Mustela frenata)300201

Horse (Equus ferus caballus)200200

Weasel spp. (Mustela spp.)200011

Bat (Chiroptera)200002

Domesticated goat (Capra aegagrus hircus)200002

Human on skis100001

952741002886114822423247359

Sheet1

Learning Curve

Huijser et al. 2016

Habitat Connectivity ???Better• Safe places to cross• Less disturbance when crossing

Worse• Wider road• Higher design speed• Increase traffic volume?• Fewer places to cross

Before

Deer and black bear crossings

© Marcel HuijserAfter

Deer: *1.623 Black bear: 1.088

Correction FactorTracks – Camera Images

Huijser et al. 2016

Habitat Connectivity

P=0.049

Huijser et al. 2016

P=0.139

Huijser et al. 2016

Concentration Of Movements in Crossing Structures?

Andis et al. 2017

• 146% more large mammal movements at structures vs surroundings

• Full connectivity for large mammals? 40.7% road length permeable !!!

• Entire ecosystems• Soil• Hydrology• Plants• Animals

Ambition level?Ecological Processes?

1. “High volume through road”

Purpose: to get from A to B fast and safe>10,000 – 15,000 vehicles/dayHigh design speedHigh posted speed limitPhysical separation traffic and wildlife

Measures:• Fences, underpasses, overpasses

Type of Road - Mitigation Approach

Type of Road - Mitigation Approach

2. “Low volume through road”

Purpose: to get from A to B fast and safe•

Type of Road - Mitigation Approach3. “Low volume park road”

Purpose: to see and experience• Low design speed • Low posted speed limit• Mitigation should not affect

landscape aesthetics

Measures:• Low design speed• Low posted speed limit• Night time closure• Seasonal closure• Gates (information, physical barrier)• Law enforcement personnel present

Cost-benefit analyses

• Costs: Equipment, installation, construction, operation, maintenance, removal

• Benefits: Reduced costs collisions

Huijser et al., 2009

Thanks!Contact: Marcel Huijsermhuijser@coe.montana.edu 406-543-2377

Road Ecology:�What Do We Know?�Human SafetyEcological Impacts Roads and TrafficSlide Number 4Slide Number 5Departure Point Matters!Collision reduction for human safety �vs. �Mortality reduction for conservation… But we mostly focus on: �human safety / reducing collisions�Wildlife Warning SignsReduce Posted Speed LimitSlide Number 11Stopping Distance – �Maximum Vehicle SpeedReduce Collisions: �Effective MeasuresCollision �ReductionUnder- and overpasses needed, �especially at higher traffic volumesCrossing Structure Types and DimensionsSpecies specific design29 Structures, 5 yearsLearning CurveHabitat Connectivity ???Slide Number 21Slide Number 22Habitat ConnectivityConcentration Of Movements in Crossing Structures?Slide Number 25Slide Number 26Slide Number 27Type of Road - Mitigation ApproachCost-benefit analysesThanks!