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Wildlife & Ecosystems

Case Studies

Listed below are examples of success stories, best practices, and/or innovative tools/approaches. This section will grow as entries are submitted or links to other sites with useful examples are provided. If you believe your agency has utilized a best practice/approach that others could learn from, please submit a short description to AASHTO (including any pertinent links) on the Share Info with AASHTO form. Please note that currently submissions are only being accepted from governmental entities.



Gopher Tortoise Conservation Area

The Alabama Department of Transportation (ALDOT) and the U.S. Fish and Wildlife Service worked for two years to set up a 600-acre preserve north of Mobile for gopher tortoises.  Gopher tortoises whose habitats are endangered by highway projects will be relocated to the preserve.  The Federal Highway Administration (FHWA) praised ADOT for developing a creative way to achieve both conservation and development and in 2004, presented ALDOT with an award for an exemplary ecosystem initiative.  For more information, read the FHWA article.

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Arizona Wildlife Linkages Assessment

As habitats become split up or fractured by human activities, the wildlife attempting to move between these areas are faced with more and more difficult challenges.  Road building, urbanization, and related infrastructure all contribute to habitat fragmentation and loss. The Arizona Wildlife Linkages Workgroup, which is a collaborative effort between public and private sector organizations, was formed to address habitat fragmentation in a cohesive, systematic approach.  Local expertise was enlisted to identify Potential Linkage Zones.  A computerized geographic information system (GIS) was used to graphically display the Habitat Blocks and Potential Linkage Zones. Over 100 Potential Linkage Zones are included in the Arizona Wildlife Linkages Map. The Workgroup’s preliminary findings were presented in a report on statewide wildlife linkages.  The tools in this report allow land managers to incorporate the identified wildlife linkage zones into their management planning processes to address fragmentation due to highways and human development. The next step is to integrate this initiative into early project planning efforts. For more information, link to the Arizona Wildlife Linkages web page

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Comprehensive Approach to Wildlife Protection

Arizona's Comprehensive Approach to Wildlife Protection on State Route 260 was designated as a State Department of Transportation Exemplary Ecosystem Initiative in 2003 and is listed on the FHWA website ( The approach involves wildlife passages along SR 260 and area-wide habitat connectivity monitoring. Along a stretch of highway with one of the highest wildlife-vehicle collision rates in the state, ADOT is building 17 sets of bridges under 17 miles of highway and across a canyon. The placement and design of the structures and the length of the adjoining fencing are based on habitat studies, interagency coordination, and "adaptive management." Video clips demonstrate many elk are using the completed passages.

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Application of Bubble Curtain Technology and Monitoring to Protect Fishery Resources During Pile Driving

In order to improve the seismic safety of the San Francisco-Oakland Bay Bridge (SFOBB), the State of California, Department of Transportation (Caltrans) is replacing the existing East Span with a new bridge immediately to the north.   This is a multi-year effort that will involve a number of construction activities on land as well as in the Bay, including the driving of 259 large-diameter piles.   In the fall and winter of 2000, Caltrans conducted the Pile Demonstration Project (PIDP) to assess the use of large hammers to install large-diameter piles at the project site.   This demonstration project gave Caltrans an opportunity to assess the sound pressure levels (SPLs) from driving large-diameter piles and test the operation and effectiveness of sound attenuation devices.   Caltrans decided to include a bubble curtain system in the specifications for the construction project.   The air bubble curtain system chosen deploys air bubbles from rings of perforated pipes surrounding the pile and template system (used for holding the pile in place).   This allows for the pile-driving operation to be completely enclosed by bubbles for the full depth of the water column and with a radial dimension of at least 2 meters.   Caltrans also committed to a fisheries and hydroacoustic monitoring program to monitor the performance of the bubble curtain in minimizing the incidental take of listed fish species.   The program consisted of: making underwater sound measurements at various distances and depths from pile-driving operations; making observations on predation by gulls and other birds; examining injured fish collected from the water during pile-driving; and conducting experiments using different species and sizes of fish in cages at different durations of exposure, distances, and depths.   Results of the monitoring program, conducted from November 2003 to October 2004, indicated that the bubble curtain was successful at reducing SPLs and reducing the number of near-term fish mortalities.   In 2005, this aspect of the East Span Project won a Caltrans Excellence in Transportation award as well as a FHWA Environmental Excellence award.

 Caltrans Excellence in Transportation award; FHWA Environmental Excellence award

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Intercounty Connector, Executive Order 13112 of February 3, 1999 -- Invasive Species

Non-native plant species are ones that have been moved from their native habitat to a new location.  A small percentage of non-native plants can cause serious problems in their new environments and are collectively known as invasive species.  Non-native species are considered invasive when they grow and reproduce rapidly, spread quickly over large areas, tolerate a wide range of climatic conditions, and thrive in areas disturbed by human activities. Subsequently, invasive plant species tend to out-compete natural species including the displacement of their habitat. Federal, state, and local agencies throughout the county work to control, and where possible, eradicate invasive species.

Executive Order 13112 (download a copy) was issued in February 1999 to prevent the introduction and spread of invasive species. The Order establishes the National Invasive Species Council (Council), which is chaired by the Secretaries of Agriculture, Commerce, and the Interior, and includes the Departments of State, Treasury, Defense, and Transportation, and the Environmental Protection Agency. The Order directs the Council to provide national leadership and oversight on invasive species and to see that Federal agency activities are coordinated and effective. The Executive Order directs all Federal agencies whose actions may contribute to the spread of invasive species to identify such actions and, within budgetary limits, use relevant programs and authorities to prevent the spread of invasive species and promote public education regarding the economical and ecological impacts that invasive species cause.

The Intercounty Connector (ICC) Project in Maryland is one of the first projects to address the Invasive Species Executive Order during the environmental process.  A Record of Decision was approved on May 29, 2006.

The proposed ICC Project is intended to link existing and proposed development areas between I-270 and I-95/US 1 corridors within central and eastern Montgomery County and northwestern Prince George’s County with a state-of-the-art, multi-modal east-west highway that limits access and accommodates passenger and goods movement.

The presence of invasive plant species was evaluated through field work. Data collection consisted of a review of existing literature provided by the Montgomery County Department of the Environmental Protection and Maryland Department of Natural Resources regarding known invasive species within Montgomery or Prince George’s Counties. Invasive species field surveys were conducted in conjunction with other field studies including forest characterization and wetland assessments. Those invasive species present were recorded for each forest stand.

Based on the field surveys, it was determined that there are several invasive species that are common throughout many of the forested areas within the study area. Invasive species more common along upland areas include Japanese honeysuckle (Lonicera japonica), Japanese stilt grass (Microstegium vimineum), and multiflora rose (Rosamultiflora). Bottomland invasive species include Microstegium species and Japanese barberry (Berberis thunbergii).

Through the construction of a new roadway, areas that were previously vegetated will be cleared, increasing the opportunity for invasive species to become established. Limiting the removal of native vegetation along either side of the new roadway will minimize impacts. Avoidance efforts will focus on minimizing impacts to forest areas, with special emphasis on minimizing forest interior impacts. A control plan will be developed, especially for more sensitive areas, such as the stream valley parks. The Lead Agencies currently have a program in place to control certain invasive species, including bull and Canada thistle, with the use of herbicides. In addition, the Maryland State Highway Administration is required to control State-listed noxious weeds as defined by the Maryland Department of Agriculture.  

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Integrated Vegetation Management Manual for Maryland Highways

The Integrated Vegetation Management Manual for Maryland Highways describes maintenance activities for State Highway Administration (SHA) roadsides and medians. These activities involve application of herbicides, mowing, and the management of woody vegetation. In order to maximize the efficiency of funds, an integrated approach was developed.  Each section of the manual provides a description of when and how the work should be performed using Best Management Practices, allowing the Administration to maximize the use of its personnel, equipment and materials resources.

Conducting these activities as outlined provides the greatest safety for the motoring public and maintenance personnel.  Activities outlined in this document encourage environmental stewardship, sustainability of the roadside, and the enhancement of aesthetics. The activities are updated annually by the Statewide Vegetation Management Team.

To obtain a copy of the document please contact:

Maryland State Highway Administration
Cashier Office
211 E. Madison St.
Baltimore, MD 21202
Telephone: 410-545-8490

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New Hampshire

Biological Control of Purple Loosestrife

Meet the Beetles: New Hampshire DOT Turns to Leaf Eating Insects to Control Invasive Purple Loosestrife Plants

At first glance, the two- to six-foot tall plant with pink-purple petals appears to be an attractive wildflower along New Hampshire’s roadsides.  In fact, the purple loosestrife has a nasty streak.  This non-native plant was introduced to the United States from Europe and Asia during the 1800’s as a medicinal herb, but it is actually a noxious weed that spreads rapidly and drives out all native plants.  This aggressive plant is found throughout the United States and Canada.  A single plant can produce more than 2.5 million seeds a year. 

Left unchecked, purple loosestrife could overrun a wetland.  By becoming the dominant plant, it could change the wetland’s entire ecosystem.

The purple loosestrife threat to moist habitats has led to efforts to control it with everything from burning, flooding, cutting and hand pulling, to chemicals.  The mechanical control efforts have proven to be both inefficient and ineffective, while spraying chemicals, although effective, poses environmental concerns when applied near water.
For several years the New Hampshire Department of Transportation (NHDOT) has recognized the need to control purple loosestrife, especially in wetland creation areas as required by wetland permit conditions.  In the late 1990’s, the NHDOT’s Bureau of Environment, in cooperation with the NH Department of Agriculture (NHDA), embarked on a four-year pilot biological control (biocontrol) program.  The idea of biocontrol is to introduce a living organism to control a pest in an infested area.

The joint NHDOT/NHDA biocontrol program included selecting the appropriate insects, finding a source for the beetles, and establishing a rearing program within the state.  Then, through controlled releases, the beetles would be placed at several purple loosestrife-invaded wetland mitigation sites and roadside locations throughout the state.  Galerucella pusillan and Galerucella calmariensis, leaf-feeding beetles that find the leaves of the purple loosestrife particularly tasty were selected. More than 130,000 Galerucella beetles were purchased and released during a four-year period. 

The results at virtually all of the NHDOT release sites were impressive.  For example, two wetland creation sites that had 75% loosestrife coverage in the City of Nashua were reduced to 5% density within five years after the beetle release.  According to a research report prepared by the New Hampshire Department of Agriculture, “the establishment of the beetles at these sites and subsequent control of loosestrife within these areas…demonstrates that the Biocontrol Program is a successful and valid method of controlling this invasive plant.  The success…demonstrates that biocontrol of loosestrife should be continued and expanded.”

As a result of the success of this program, the New Hampshire Department of Transportation has continued its beetle release program beyond the initial four-year period.  The NHDOT is satisfied that the biocontrol of purple loosestrife program has not only increased the biodiversity of its wetland creations sites, but is also a key component in controlling this invasive species throughout New Hampshire.

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New Mexico

Prevention of Vehicle-Animal Collisions

New Mexico Department of Transportation

The NMDOT is an active partner with the NM Department of Game and Fish to develop strategies to prevent vehicle-animal collisions.  This partnership was fostered by a NM House Joint Memorial in 2004. One of the most important initiatives of the partnership has been to identify important wildlife corridors that cross highways, and to develop animal crossings along those corridors. Wildlife crossings are being constructed mainly for deer, elk, and black bear. To date, five significant wildlife corridors have been identified. One corridor crosses US 550 north of Aztec in San Juan County. Three wildlife underpasses were constructed along this corridor as part of the recent US 550 construction project. Another important wildlife corridor crosses I-25 in Tijeras Canyon east of Albuquerque. Wildlife underpasses will be included as part of the I-25 construction project. Plans are also underway to develop wildlife crossings as part of future construction on US 64 between Clayton and Raton in Colfax and Union Counties, on US 54 between Carrizozo and Vaughn in Lincoln and Torrance Counties, and on US 70 east of Las Cruces in Dona Ana County. These wildlife corridor projects represent a commitment by the NMDOT to be a good steward of the environment while at the same time providing greater safety to the traveling public.

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New York

Invasive Species in the Adirondacks

The spread of invasive, non-native plants threatens to seriously damage or even destroy unique native plant communities, critical wildlife habitat, and scenic panoramas in upstate New York’s 6-million-acre Adirondack Park.  The problem plant species are primarily concentrated along transportation corridors.

The NYSDOT has been working with other government agencies and non-governmental organizations to control the spread of invasive species since 1998.  These partnership efforts have been formalized in the Invasive Plant Program (IPP).  The IPP has become a comprehensive, regional invasive plant program engaging professionals and the public alike and providing critical information on which management strategies are most successful.   To do this, the IPP uses the best available science, including a Geographic Information System (GIS) mapping tool pioneered by NYSDOT to relate known locations of invasive species to the State highway route marker system so the locations can be seen on interactive maps.  The GIS maps will be integrated with a tracking database system used statewide.

The IPP has expanded to involve numerous professional and volunteer groups.  One of the latest groups to get involved has been the Adirondack Mountain Club, which has more than 20,000 members.   The Club has written articles and conducted training sessions on how to recognize invasive plants in the back country.

Controlling invasive plant species in the Adirondacks is largely a matter of experimentation, trying out different control methods, and combining different strategies.   Experiments in burying Japanese knotweed under project waste material and geotextile fabric have been completely successful.   At Long Lake, a 10-mile section of the park is being used to test various combinations of hand-pulling, herbicide applications, and mowing practices to eradicate purple loosestrife.   Throughout the park, roadside projects are using certified weed-free straw mulch to control the spread of invasive plant species.  At Indian Lake, common reed was removed and composted for three years under black plastic.   The composted material has now been transferred to a landscaping berm at a NYSDOT location where it can be watched to make sure the invasive plant doesn't reappear.

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North Dakota

A Collaborative Initiative to Replace Designated No-Mow Areas Along Highway Rights-of-Way

The North Dakota Department of Transportation (NDDOT), in cooperation with the Federal Highway Administration (FHWA), North Dakota Game and Fish Department (NDGFD), and the US Fish and Wildlife Service (USFWS), has used a variety of strategies to mitigate unavoidable losses to important wildlife habitats.

Beginning in the 1970s, NDDOT and the participating agencies developed an agreement to designate specific road rights-of-way as no-mow or managed-mow mitigation sites to offset impacts associated with highway construction activities. A total of approximately 8,200 acres, comprising 363 miles of right-of-way were designated. The no-mow areas were established, in part, to mitigate for the unavoidable loss of 136 acres of prairie pothole wetlands, as research indicated higher waterfowl nesting success in areas of unmowed right-of-way.

In 2001, the North Dakota State Legislature directed the NDDOT to develop a plan for replacing the no-mow areas. NDDOT worked with participating agencies to explore environmentally sound, cost-effective measures to replace the sites. NDDOT worked directly with the NDGFD and the State Land Department to evaluate state school land tracts throughout the state. This dedicated effort resulted in the purchase of 3,461 acres of land owned by the State Land Department and acquisition of approximately 740 acres of reclaimed mine land from Great River Energy.

The designated tracts will be managed by the NDGFD. The sites, ranging in size from 160 to 640 acres, provide permanent protection of larger blocks of diverse habitat that will support a great variety of wildlife than the no-mow areas. In addition to managing these tracts as wildlife management areas, NDGFD will make in lieu of real estate tax payments, equal to the evaluation for real estate taxes, to support county and local governments, and assume all costs associated with managing the lands for 99 years. This well coordinated, collaborative initiative released the NDDOT and FHWA from the commitment to maintain the no-mow areas in North Dakota.

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Biological Assessment Manual and Qualification Program

A Biological Assessment Committee (BAC) was convened in the fall of 2004 to develop and implement a plan to improve the quality of consultant-delivered Biological Assessment (BA) documents.  The committee was chaired by the ODOT Natural Resource Manager.  Membership included stakeholders and representatives of ODOT sections and external agency partners who provide the information and processes necessary to shape a sound program.  The team established 2 desired outcomes: (1) to develop a training program establishing ODOT expectations and (2) to develop a process that ensures BA documents of a consistent quality. 

The goals of the BAC were as follows:

  • Create a standardized training program on interagency consultation under ESA that is specific to transportation.
  • Develop a method to consistently better manage consultants across agency.
  • Involve representatives from all agencies involved in consultation.
  • Improve BA document quality over time.
  • Create efficiency in interagency consultation.
  • Create a uniform and transparent process for consultants contracting with ODOT.
  • Obtain feedback regarding effectiveness of training.
  • Reduce cost of deliverables.

The Biological Assessment Manual and Qualification Program became effective in June 2005.  Consulting firms interested in performing BA consultation work for ODOT must first be qualified.  Consultants are required to meet minimum professional qualifications.  These minimum qualifications include three years of environmental analysis or resource project management experience and a Master's degree with 30-quarter or 20-semester hours in an environmental or natural sciences such as biology, ecology, or a closely related field.   Three additional years of environmental analysis or natural resource project management experience with evidence of professional documentation may substitute for the Master’s degree.  Consultants are also required to attend a two-day ODOT training course developed in partnership with FHWA, NMFS, and USFWS.  Following the training, consultants are required to demonstrate understanding of the material by passing a written examination.

To maintain quality, consultants are required to use a standardized BA Template and Checklist while preparing BAs.   Consultants are subject to Consultation Feedback Reviews (CFR), a scored assessment conducted by the ODOT liaison staff at NMFS and USFWS.  The CFR score reflects the quality of BA completeness, readability, and format as outlined in the BA Template.  If the CFR score falls below 70%, a notification letter is sent to the consultant and his or her firm.  If the qualified biologist’s score is not maintained above the 70% threshold, the individual will loose their qualified status.

As of early 2006, fifty consultants have been trained and qualified.  The quality of BA documents has shown improvement through implementation of the program.   No failing BAs have been reported since qualification.

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Migratory Bird Treat Act Guidelines and Strategies

On January 17, 2006, ODOT signed a Highway Division Directive on the Migratory Bird Treaty Act (MBTA). View a copy of the Directive. The Directive provides guidelines and strategies to ensure that appropriate and reasonable measures are taken to prevent injury to and death to migratory birds for agency personnel involved in project delivery, construction, and maintenance. ODOT is committed to environmental stewardship and supporting the conservation intent of the MBTA while designing, constructing, operating, and maintaining the state highway system through Context Sensitive and Sustainable Solutions. ODOT Highway Division employees are to incorporate the MBTA Guidelines and Strategies into their work responsibilities. Because each project provides its own set of MBTA challenges, the MBTA Guidelines and Strategies recognize the need for flexibility in selecting compliance strategies by providing a suite of possible options for consideration on a project-by-project basis.

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Allegheny River Freshwater Mussel Studies

FHWA Exemplary Ecosystem Initiatives

Allegheny River Freshwater Mussel Studies
Upper/Middle Allegheny Drainage, Pennsylvania

Since the mid-1990s, the Pennsylvania Department of Transportation (PennDOT) has been extensively involved in informal and formal consultation processes for bridge replacement projects in the Allegheny River Drainage.  In order to improve scientific data, document success of best management practices and reasonable and prudent measures, PennDOT partnered with the United States Geologic Survey, Biological Resources Division (USGS-BRD) to conduct comprehensive qualitative and quantitative surveys of the Upper/Middle Allegheny River.  These studies confirmed that mussel densities in the Allegheny River are greater than previously known.  Twenty four (24) species have been identified during the survey to date.  These results will now be the basis for future Section 7 consultation decision-making for USFWS and PennDOT.

Several mussel relocations associated with bridge replacements on the Allegheny River have been completed and extensive monitoring of the success of relocation and re-colonization of impacted areas was undertaken by PennDOT and USGS-BRD.  Again, the results have been positive with documented successes in relocation and re-colonization far exceeding expectations in impact areas.  These results provide new information useful in the development of best management practices and prudent and reasonable measures for bridge/freshwater mussel conflicts. See FHWA Exemplary Ecosystem Initiatives for additional information.


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Kettle Creek Steam Restoration and Wetland Bank

FHWA Exemplary Ecosystem Initiatives

Kettle Creek Stream Restoration and Wetland Bank
Potter County, Pennsylvania

Multiple agencies and interested parties with widely varying goals collaborated to implement this stream and wetland restoration and wetland banking project.  The parties involved included PennDOT, United States Fish and Wildlife Service, Pennsylvania Department of Conservation and Natural Resources (DCNR), Pennsylvania Fish and Boat Commission, Trout Unlimited, and the Kettle Creek Watershed Association. The PennDOT goals for the project were: 1) implementation of a stream restoration utilizing hydrogeomorphic (HGM) methods to move the energies of Kettle Creek away from a state route to eliminate flooding; and 2) wetland banking for future transportation impacts to reduce costs of mitigation and permit review times for individual transportation projects. 

The wetland bank has been noted by the Pennsylvania Department of Environmental Protection (DEP) as one of their top three picks for successful wetland mitigation banks in Pennsylvania (DEP 2004 Annual Wetland and Water Obstruction Report).  The wetland site, although small, has extensive vegetative diversity with 55 species recorded (more than 34 wetland species) and notable herpetological production. The additional flood storage was exceptionally successful during Hurricanes Francis and Ivan, retaining water that would likely have increased property damage downstream.  The project is located on DCNR state forest land, increasing the active and passive recreational values of the state forest.  See FHWA Exemplary Ecosystem Initiatives for additional information.


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I-15 Wildlife Crossing

Interstate 15 in Utah, from the city of Beaver to the Cove Fort interchange, was an area with a high number of vehicle/wildlife accidents. In 2004, road improvements were made to improve safety, especially those resulting from collisions with wildlife. The improvements included the construction of two wildlife underpasses, deer-proof fencing along the entire section, and earthen escape ramps approximately every quarter mile to allow deer that enter the right-of-way to escape. In order to evaluate the success of these measures, the Utah State University, Department of Forest, Range, and Wildlife Science, USGS Utah Cooperative Fish and Wildlife Research Unit has been conducting a research project to monitor the roadway during three deer migration periods (Fall 2004, Spring 2005, and Fall 2005). Cameras installed at the entrance of the culverts show that the deer have adapted to these structures, but elk are more reluctant to use them. A report of the monitoring results will be available in Spring 2006.  Initial results indicate that the accident rate in the project area has been greatly reduced.

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VTrans Habitat Training

For the past four years the Vermont Agency of Transportation has used FHWA planning and research funds to host a habitat and transportation training program. This series of trainings engages participants in a dialog that focuses on road ecology issues in the northeast. It is a mixture of classroom seminars and field excursions exploring the habitat and natural history of focal species mammals, reptiles, and amphibians. The course consists of eight sessions spread over approximately six months. Throughout the course, participants discuss and investigate the impacts of transportation on habitat. The goal of this course is to develop awareness and understanding of habitat connectivity issues so that transportation professionals can incorporate ecological connectivity into the planning and design of transportation projects. The course tackles complex road ecology and environmental stewardship issues in a forum outside of the often confrontational regulatory/project arena. The course is co-taught by Jim Andrews, a research herpetologist from Middlebury College, and Susan C. Morse, a wildlife photographer, tracking expert, and founder and research director of the nationally recognized Keeping Track Inc.   John Austin, Wildlife Biologist from the VT Department of Fish and Wildlife, also participates in the trainings as a technical advisor. On occasion, additional guest presenters bring unique perspectives into the program.

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Woodrow Wilson Bridge Project

The Woodrow Wilson Bridge Project will construct a new 12-lane drawbridge on Interstate 95 with four adjacent major interchanges.  Possible environmental degradation was a huge concern since the project will be built in the Potomac River, its tributaries and wetlands along its corridor.  An environmental management group was created that comprised three teams: a leadership team, a mitigation team, and an environmental inspection team.  As a result of a high level of integration and coordination among these teams, the environmental group quickly and creatively overcame many challenges.  Some of the highlights include:

  • Obtaining all permits in about 12 months;
  • Locating a disposal site to accept dredged material;
  • Developing and deploying an air bubble curtain to protect fish during pile driving;
  • Creating a permanent 84-acre bald eagle sanctuary in Prince George’s County, Maryland;
  • Establishing 11 acres of tidal wetlands in Stafford County, Virginia;
  • Removing 23 man-made stream blockages;
  • Planting river grasses;
  • Creating parkland; and
  • Preserving habitat.

The project has also received regulatory permission to use the demolished concrete substructure of the old bridge to create fish reefs.

The project received the 2004 Globe Award from the American Road and Transportation Builders Association’s Transportation Development Foundation for overcoming major environmental challenges.  The environmental successes of the Woodrow Wilson Bridge Project show how enlightened environmental stewardship can and should be used in construction of infrastructure projects.

For additional information, please see the article from the Transportation Builder.

 2004 Globe Award

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I-90 Snoqualmie Pass East Project Improves Mobility for People and Wildlife

A project to construct needed improvements to a stretch of mountain highway in Washington State will provide new opportunities for moving people through the corridor and reconnecting wildlife habitat and natural systems, which for years have been fragmented by the roadway.

Washington State DOT and partner agencies worked to develop innovative solutions for the I-90 Snoqualmie Pass East project, to achieve needed safety and mobility improvements for drivers, provide safe passage for wildlife, and reestablish vegetation and hydrologic connections across the roadway.

The solutions were developed by a unique partnership of agencies – including state and federal transportation agencies and the U.S. Forest Service, which manages the surrounding land – as well as other agencies, nonprofit conservation and public advocacy groups, universities, and citizens.

The 15-mile project area is on National Forest land and must be compatible with the U.S. Forest Service’s adaptive management plan for the area.

The DOT agreed to include wildlife connectivity along with transportation improvements as a part of the project purpose and need statement.  The environmental impact statement specifies that the project is intended to meet traffic demands and improve public safety by addressing avalanches and slope instability, repairing structural deficiencies in the existing roadway, and expanding capacity, while also providing for ecological connectivity.

Regarding highway improvements, the project will:

  • expand the roadway from two lanes to three lanes;
  • replace the concrete pavement, straighten dangerous curves, and provide additional chain-up areas for trucks,
  • construct a new six-lane snow shed for protection from avalanches, and
  • stabilize dangerous slopes to reduce rock fall hazards.

In addition, wildlife passing structures are planned at 14 major wildlife crossing areas as part of the project. Structures include replacing narrow bridges and culverts with longer and wider structures to facilitate wildlife passage; adding wildlife exclusion fences to keep animals off the highway; and adding wildlife overcrossings at strategic locations.

A key aspect of the project was the identification of 14 separate “connectivity emphasis areas” – locations near streams or upland that can benefit fish, wildlife and hydrologic functions through restoring or enhancing a connection to habitat on both sides of the road. The areas were identified by a multi-agency mitigation development team.

Gold Creek Bridges and Wildlife Crossing

Gold Creek is one example of a connectivity emphasis area on the project, with improvements planned to achieve wildlife passage, hydrological connectivity, and re-establishment of vegetation.

The existing bridge structures at Gold Creek are 138-feet and 126 feet long, with a large quantity of imported fill within the floodplains and wetlands – a situation that has allowed little connectivity for aquatic or terrestrial species. Roadway improvements will replace the existing structures with wider and longer spans – two 1100-foot structures – and add a new wildlife undercrossing, all designed to improve connectivity and restore ecological functions.

Gold Creek was among the project areas that also benefited from partnerships among agencies and conservation groups to acquire private land to protect and contribute to the effectiveness of the conservation emphasis areas.

Over the last 15 years, a coalition including the Cascades Conservation Partnership, the Mountains-to-Sound Greenway Trust, the U.S. Fish and Wildlife Service and U.S. Forest Service have invested more than $100 million to protect land in the I-90 project area. Through combinations of land purchases and exchanges, the partnership has added 75,000 acres of conservation land and National Forest land within the area.

The Gold Creek improvements will allow multiple benefits – connecting wildlife habitat for small and large species while also helping to restore achieve hydrologic connectivity and providing mitigation for wetlands impacts.

Other noteworthy aspects of the project’s environmental commitments include creative solutions that combine benefits for wildlife connectivity and wetland mitigation and efforts to test and reestablish native vegetation in ecologically challenging environments.

In addition, the project includes extensive efforts to monitor wildlife occurrences – both before and after construction of wildlife crossings – to determine the effectiveness of the structures.

The monitoring program includes a unique public involvement effort, I-90 Wildlife Watch, in which citizens are encouraged to help gather data on wildlife in the area and to report wildlife sightings – including live animals or victims of collisions with vehicles.

The many environmental commitments of the project were in part the result of the extensive collaborative effort of the environmental review process itself, which was led by an interdisciplinary team including FHWA, WSDOT, USFS, USFWS, and Washington Department of Fish and Game. In addition, a range of other advisory committees, consultations, and partnerships with agencies, organizations, and the public helped to streamline the process of developing the Environmental Impact Statement. The project received FHWA’s 2011 Environmental Excellence Award in the category of Environmental Streamlining.

For more information, visit the project website at

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US 97A Wildlife Fence Project

The Washington State Department of Transportation and the Washington Department of Fish and Wildlife have partnered on a project to construct a wildlife fence on a nine-mile section of the US 97A corridor in Chelan County, Wash., to reduce vehicle-wildlife collisions with bighorn sheep and mule deer. One challenging aspect of the project was building a fence that can control bighorn sheep, which are adapted to climbing steep terrain.  WSDOT consulted with wildlife experts on research into the bighorn sheep’s habits and abilities, leading to several innovative design elements. New features include installation of the eight-foot tall fence on relatively flat terrain between natural barriers such as high cliffs; use of camouflaged, one-way push gates allow wildlife caught on the highway side of the fence to escape; and use of 16-foot wide wildlife “cattle guards” to allow property owner access. For more information, link to WSDOT’s Quarterly Environmental Highlight on the US 97A Wildlife Fence Project and to the project website. (8-18-10)

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Hoh River Engineered Logjams

For the better part of two decades, a remote two-lane stretch of U.S. Highway 101 in western Washington took a recurring beating from the floodwaters of the Hoh River, which flows to the Pacific Ocean from the glaciers and rainforest of the Olympic Mountains. The WSDOT engineers urgently needed to find a long-term solution that would not only protect the highway infrastructure, but would also minimize environmental impacts. With the help of FHWA, WSDOT was able to implement an innovative strategy consisting of an emerging technology called engineered logjams (ELJs). The U.S. Army Corps of Engineers and the U.S. Fish and Wildlife Service strongly endorsed the project. The manmade logjams mimic those found in nature. In a natural river system, logjams typically form when a large tree falls into the water and becomes embedded in the river bottom, creating a snag that captures additional logs and debris moving downstream. Such logjams are capable of redirecting the channel and slowing the water’s destructive forces. As an additional benefit, the logs and debris create or enhance fish habitat.  An article about the project was included in the January/February 2006 issue of Public Roads magazine. Download the article or access it online at

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Relocation of Karner Blue Butterflies

WisDOT Moves Karner Blue Butterflies by the Bushel

US Highway 10 cuts through the middle of Wisconsin, connecting the Fox Valley Cities in Wisconsin with the Twin Cities of Minnesota.  This main traffic artery needed to be upgraded from a two- to four-lane expressway.  Unfortunately, the new westbound lanes cut through a small 1/3 acre patch of Wild Lupine (Lupinus perennis) and native barrens habitat that was occupied by Karner Blue Butterflies (Lycaeides melissa samuelis) (view a picture of a Karner Blue Butterfly, a federally endangered species.  Recent surveys indicated a population of at least 10-20 adults consistently bred on this tiny patch of habitat. 

WisDOT is part of a multi-partner Habitat Conservation Plan (HCP) for the Karner Blue.  WisDOT accommodates Karners along about 500 miles of highway right-of-way in central and northwestern Wisconsin.  After going through the usual mitigation negotiation procedures of avoidance and minimizing, it appeared there was no way this swatch of earth could be spared from the new lanes.  Another question arose as to the future viability of the Highway 10 site for the butterflies.  It was unrealistic that a site this small, surrounded by Eurasian weeds, in the presence of a major highway, would remain viable in the long term.  During the mitigation process, WisDOT began to explore the possibility of moving the butterflies.  Although ideas about moving butterflies had been written about, no one had previously done this in the wild. 

Fortuitously, the Wisconsin Department of Natural Resources (DNR) just completed removing brush and most of the trees from an area near Emmons Creek, a lupine barrens community.  Wild Lupine responded very well to the DNR barrens restoration effort, along with several other butterfly nectaring plants, but several surveys indicated that no Karners moved in to take advantage of the restored habitat.  This presented an opportunity to move the Highway 10 population to the newly restored area.  

The easiest way to move butterflies is in the egg stage.  Karners conveniently lay almost all their eggs on the stems of Wild Lupine near the base of the plant.  Methods included marking each Wild Lupine plant during peak flowering period, then after the egg laying period, clipping the Wild Lupine at the base of the stem with either a knife or clippers, gently laying the stems in large plastic bins and transporting the stems to the new site.  The clipped stems were then inserted in the midst of living lupines at the Emmons Creek site.  It seemed fairly straightforward, but there were a few questions.  Would the eggs over-heat in the sun during the move and die?  Would the eggs remain attached for the ride to their new home?  After hatching, would the larva climb from the clipped stems to living plants?  

To help with these potential pitfalls, the bins containing the clipped lupine stems with the Karner eggs were not tightly covered and were shaded from direct sun light.  Fortunately, the weather during egg movement was relatively cool, with cloudy, nearly windless days.  It is believed these weather conditions helped preserve the eggs from overexposure during movement.  Care was taken not to over-pack or crush the bins with lupine stems.  Once cut and placed in the bins, batches were moved within an hour to the new site.  During the clipping portion of the work, a number of eggs were observed (3-6 on some stems) and it was noted that a few larvae had already hatched and were actively feeding on the lupine.  The clipped stems were placed in the middle of healthy plants at the new site with as much contact between each as possible. 

About 120 pounds of stems and leaves were removed from the Highway 10 site.   Once this movement was complete, it was time to wait for eggs to hatch, larva to pupate and form new adults.  About six weeks after the move, surveys were conducted at the new site for adults.  It was very gratifying to report that 42 adults were observed on the new site where none had been seen before.   It appears that the larva did find their way to new lupine stems and successfully pupated to adult butterflies. 

This process may have implications for other butterflies, and perhaps even other insects.   If the host plant and egg laying process is known, capture and release of these species can be quite easy, with minimal disruption to the individuals themselves.   This may also provide a method for population expansion to new areas, or at least within nearby, similar, ecological areas.

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Wyoming DOT Provides Safer Passage Where Highway Meets Migrating Pronghorn

A series of underpasses and overpasses recently completed along a Wyoming highway has improved safety for the traveling public while preserving an historic wildlife migration route for pronghorn antelope and mule deer. Completed in October 2012, the Trappers Point project included design and construction of two overpasses and six underpasses on a 12-mile section of US 191, west of Pinedale.

Each overpass consists of a long-span precast-concrete arch culvert constructed over the highway to provide an artificial tunnel over which wildlife can cross safely. The culverts are surrounded by earth berms supported on each end by large precast-panel retaining walls. The project also includes about 30 miles of special fencing to direct animals to the safe crossings.

Historic Migration Route

In an area known as the Upper Green River Valley corridor, pronghorn travel between their winter range in the high desert, south of Pinedale, and their summer range in Grand Teton National Park. The corridor, which represents the second-longest wildlife migration route in the Western Hemisphere, intersects with US 191 at Trappers Point.

The Trappers Point area was named for the nineteenth-century fur trappers who took advantage of natural terrain that bottlenecks the migratory herds. In modern times, it had become the site of frequent vehicle collisions with pronghorn, mule deer, and other animals.

Seeking to address this concern, a collaborative effort between WYDOT and a number of state and federal agencies and other organizations identified key locations where wildlife crossing structures could be beneficial. To facilitate the passage of pronghorn – which are reluctant to use traditional wildlife underpasses – WYDOT committed to build its first-ever wildlife overpasses.

Trappers Pond Wildlife Crossing. Photo: Wyoming DOT

Locations for the various crossing structures were chosen based on areas with the highest instances of motor vehicle collisions, observations by local game and fish and WYDOT personnel, and studies of the movement of collared antelope and deer.  The agencies also considered the terrain, as well as already-preserved movement corridors, such as public lands or conservation easements.  

Development of the wildlife connectivity plan for the area was a collaborative effort that included the Wyoming Game and Fish Department, the U.S. Forest Service, the Bureau of Land Management, the U.S. Fish and Wildlife Service and the Federal Highway Administration. It also incorporated wildlife research from organizations including the National Fish and Wildlife Foundation, the Biodiversity Conservation Alliance, the Greater Yellowstone Coalition, the Wyoming Outdoor Council, the Rocky Mountain Elk Foundation, and National Geographic.

Focus on Highway Safety

The agencies initially collaborated in an effort to obtain funding for the project under the American Recovery and Reinvestment Act. When that funding fell through, WYDOT was able to continue the effort by stressing the importance of highway safety: the combined loss of wildlife and property damage to vehicles was estimated at nearly $4.1 million from 2005 through 2009.

Under the focus of highway safety, WYDOT was able to secure the National Highway System federal funds to advance the project, according to Tim Stark, Environmental Services Engineer with WYDOT.  The funds are expected to provide a valuable return. According to WYDOT, “The savings from reducing wildlife deaths and damage to vehicles is expected to exceed the project cost of $9.7 million in 12 years.”

Monitoring Shows Promising Results

The project already has proven to be beneficial for thousands of animals that have found their way safely across the highway. The most recent monitoring, conducted between Oct. 1 and Dec. 15, 2012, used remote cameras to document 8,878 mule deer and pronghorn moving through the new crossing structures.

Wildlife crossings help pronghorn safely cross the highway. Photo: Wyoming DOT

These results were particularly encouraging by demonstrating pronghorn’s use of the overpasses. Of the 8,878 animal crossings, 2,442 were pronghorn and 6,436 were mule deer. While most mule deer moved through the underpasses, 92 percent of the pronghorn used the overpasses. “The Trappers Point overpass is so well designed and so well suited to accommodate pronghorn migration, that we observed pronghorn using the overpass even before completion,” Jeff Burrell, Northern Rockies program coordinator for the Wildlife Conservation Society, said in a release. Stark said WYDOT will consider lessons learned from the Trappers Point project in planning for future efforts to ensure the safety of travelers and wildlife.

The Trappers Point project has received numerous awards, including the Wyoming Engineering Society’s 2012 President’s Project of the Year and the Federal Highway Administration’s 2011 Exemplary Ecosystem Initiative award. A National Geographic video featuring the project also is posted on the WYDOT website.

For more information on Trappers Point and other wildlife protection projects, visit the WYDOT Wildlife and Fisheries website, or contact Tim Stark, WYDOT Environmental Services Engineer, at or by phone at 307-777-4279.

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FHWA Compilations

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CEE by AASHTO Stewardship Competition

Best Practices in Stewardship Competition

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Forest Service Compilation

Wildlife Crossing Toolkit (USDA-FS)

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Defenders of Wildlife Report

Second Nature: Improving Transportation Without Putting Nature Second (2003) (Defenders of Wildlife)

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