Many state and federal transportation and environmental agencies have signed on to the idea that planning for environmental protection early in transportation system development and improvement is more likely to result in sustainable and less-contentious solutions. We developed a method for Caltrans to use economic valuation methods to improve environmental impacts analysis and project selection.
The effect of roads and highways on natural systems is defined geographically as the road effect zone (REZ). This term was coined by Dr. Richard Forman (founder of the field of road ecology) and is integral to how road ecology is expressed in planning and impact assessment. The zone of impact varies in types and degree of impact, based on distance from the roadway, environmental conditions, and traffic intensity. We use GIS tools to model components of the REZ, such as traffic noise, to confirm our predictions in the field.
As the climate changes, it is likely that we will continue to experience sea level rise, the result of the ocean expanding due to warming and melting of glaciers. Coastal transportation may be affected in low-lying areas, as will natural systems in close proximity to the infrastructure. It is likely that the best way to protect natural and transportation systems from the effects of sea level is to plan for them together where roads and highways abut coastal bluffs, marshes, estuaries, and beaches. We are developing tools to record the change in coastal systems at fine spatial and temporal scales to inform short and long-term planning for important and imperiled coastal systems.
Road and highways can have dramatic effects on wildlife movement and landscape connectivity. Some species may have complete aversion to roads, which would limit their movement through landscapes with roads. Other species may try to cross roads even with traffic present resulting in wildlife mortality and risks to drivers. We study the impact of roads on wildlife movement at multiple geographic scales, from individual animals at road crossing structures, to hypothetical movement pathways at the landscape scale.
