Over the last 20 years, road ecology has evolved into transportation ecology, involves new partners, and is increasingly playing a role in transportation decision-making and legislation. The greater diversity of partners, disciplines, decision points, and transportation types raises challenges for the field. Overlaying and part of these changes are overarching issues of justice-equity-diversity-inclusion, climate change, adequacy of our management actions, and scientific rigor. The charge for the field going forward will be to deal with these issues across a growing network of mandates, opportunities, partners, and needs. I use a literature review of several fields in transportation ecology, review of state transportation activities, and case studies to formulate and raise several primary issues I see for transportation ecology going forward, as well as possible resolutions:
1) Climate change is likely to result in inter-regional migration of people within and among countries. It is unlikely that receiving areas have planned for these migrants, including possibly new transportation systems with new impacts.
2) Modeling of direct climate change impacts to costly shoreline infrastructure has wide ranges of uncertainty, which could lead to adaptive responses to sudden changes putting other values at risk. For example, there are proposals in CA, WA, and other states to use hardened barriers to prevent flooding of coastal urban areas, which may accelerate the loss of nearby shorelines due to reflected energy.
3) Wildlife adaptation may require more crossing structures across road and railways and greater pressure on ecological modeling to identify locations. The uncertainty in describing where and how connectivity should be protected for 70-year lifespans of structures is under-recognized and because it is a wicked problem, is usually considered impossible.
4) As transportation ecology has grown, there has been parallel growth in mitigation by transportation agencies, due to pressure from scientists and environmental groups warning of legacy and new impacts as well as individuals within transportation agencies embracing science. However, there are two gaps in responses: a) understanding the adequacy of responsive actions (e.g., mitigation) compared to the scale of problems being addressed; and b) the necessity to address legacy impacts of transportation not just mitigating impacts from new transportation projects.
5) A common, but untested assumption is that our scientific expertise, tools, and data are sufficient to inform adequate mitigation. There is also reluctance among some in transportation to engage PhD academic scientists, though the use of PE professional engineers for other transportation needs is widely embraced.
Going forward, “no-regret” strategies should be developed that address multiple timeframes and interactions between built and natural infrastructure. We must move beyond example and mitigation projects and tackle the big and wicked problems in transportation impacts on ecology. Finally, an improved balance is needed between future transportation systems and demonstrably-sufficient science.