Adapt vulnerable transportation infrastructure to be responsive to weather events and climate change

Most of the region’s roads were designed using standards that pre-date the increased number of freeze-thaw cycles, heavy rain events, and hotter, wetter conditions posed by the region’s changing climate. Transportation modernization efforts should promote infrastructure that is built or retrofitted to revised design standards that take the anticipated climate of the region into account. Identifying locations at risk of flooding and then retrofitting these locations to handle current and future rain events can help maintain regional and local mobility, appropriately balance increased up-front costs with risk, and ensure that investments are built to last. The Regional Transportation Authority, Illinois Department of Transportation (IDOT), and several county transportation agencies are already working to identify portions of the existing transportation system that are vulnerable to flooding and incorporating solutions into their long-range capital plans or operational response plans.

At the local level, municipalities must also address the vulnerability of their streets to flooding and other climate change impacts. Through the Local Technical Assistance program, CMAP could assist communities in vulnerability assessments to help inform capital improvement plans and corresponding design considerations. As new information on precipitation trends evolves and floodplain maps are updated, the local and regional vulnerability assessments should be updated periodically to reflect changing conditions. While the above assessments will help identify existing assets at risk of flooding, the region also should work to avoid expanding new streets and highways into flood prone areas. Avoiding road construction in floodplains may not always be possible; where necessary, such roads must be designed with future climate conditions in mind.