Abstract:Landscape fragmentation disrupts ecological flows, reduces wildlife movement, and imperils aquatic and terrestrial systems. Two primary drivers of fragmentation are human land uses and transportation systems, which also influence each other. One aspect of road ecology is the study of the effects of road systems and road use on ecological flows (e.g., wildlife movement). At national and state scales, agencies and scientists are investigating the ways that roads and traffic fragment landscapes and ecological processes. Most contemporary research points to the importance of existing road and highway systems in reducing habitat quality and imperiling species. One way that state and federal transportation agencies are responding to this is to improve wildlife-highway interactions through constructed crossings and modified traffic patterns. These activities are consistent with federal transportation law (SAFETEA-LU) and the California Wildlife Conservation Strategy, which lists habitat fragmentation as a major stressor on wildlife. Another current activity is the proposed “Statewide Connectivity Project,” a collaboration among state agencies, universities, and non-governmental organizations. Critical in active crossing facilitation is evaluation of the effectiveness of the management action, in order to inform future decisions. A combination of focused research, wildlife crossing facilitation, and supportive policy will create an environment where we may repair some of the lost connections across the landscape.