There are many agencies, organizations, and coalitions working on the complexities of roads, wildlife, and connectivity.
Federal Highway Administration Critter Crossings
USDA Forest Service, particularly Pacific Southwest Research Station - Wildlife Crossings Toolkit
Defenders of Wildlife Habitat and Highways
Highway 3 Transportation Corridor Project, Alberta/BC, Canada
Ontario Road Ecology Group, Ontario, Canada
Road Watch in the Pass, Alberta, Canada
Wildlife Conservation Society, Rockies