A Computer Model for Exploring Highway-Wildlife Relationships

What guidelines can transportation planners use to identify future wildlife crossings? How will they prioritize these projects? How can wildlife conservation be integrated with other environmental initiatives to make the best use of limited resources?

Researchers in the University of Florida's Landscape Ecology Program have devised a solution. They have developed a Geographic Information System (GIS) computer model that captures, manipulates, displays, and combines spatial information such as hydrology, land use, species distribution, and existing roads and greenways.

The statewide, geographically referenced planning tool has arrived at a critical time. Close to 48.7 million tourists visited Florida last year - 43 percent arriving by car - and 700 people a day move into the state. As Florida's population continues to grow, so does the demand for more roads.

The GIS model will help FDOT integrate the need to improve transportation with the need to counteract increasing habitat fragmentation by roads. Transportation planners can use it to identify and prioritize roadkill "hot spots" - habitat corridors where wildlife-vehicle collisions are likely to occur. They can then adapt existing crossing structures or build new ones (like the highly-successful underpasses on I-75 - "Alligator Alley" - designed for the federally endangered Florida panther).

State roads in Florida were prioritized according to overall environmental impact. This map displays the results of the analysis for northeast Florida. The areas shown here in red represent those road segments that ranked high in the road prioritization analysis. Primary criteria influencing high rankings included chronic roadkill sites, biodiversity hot spots, riparian systems, greenway linkages, and rare habitat types.

The project began with a survey of transportation and wildlife experts, who evaluated and ranked criteria for prioritizing projects aimed at reducing roadkills and restoring ecological linkages. Individual criteria corresponded to relevant spatial "datasets." For example, "chronic roadkill sites," ranked #1 by survey respondents, corresponded to data on known roadkill locations for Florida panther and Florida black bear and roadkill data for state and federal parks and preserves.

The project identified 72 "priority one" road segments and hundreds of lower-priority segments. It also named the highest-priority roads in each of Florida's seven districts - for example, State Route 29 and U.S. 41 in the Everglades - and noted the contributing criteria for each.

University researchers are conducting field studies to evaluate the context and condition of any existing crossing structures on prioritized segments. They've identified hundreds of structures so far, many of which only need minor adaptations like directional fencing and vegetative screens to enable wildlife to move safely across highways.