News Updates

New data shows our transportation system’s vulnerability to climate hazards

Northeastern Illinois is feeling the effects of climate change. Hazards like intense storms and high temperatures put both transportation infrastructure and users at risk. In the future, these impacts are projected to become more frequent and intense across the region.

The Chicago Metropolitan Agency for Planning (CMAP) seeks to improve the resilience of the region’s transportation network — roads, bridges, culverts, transit, and regional trails — to extreme weather and climate change. Through the Transportation Resilience Improvement Plan (TRIP), we are identifying regional transportation assets vulnerable to climate change and prioritizing them for equitable resilience investments.

The first phase of TRIP, a risk-based vulnerability assessment, uses recent trends and projections to analyze climate risks. The report identifies:

• Which climate hazards are the biggest threat to the region and its transportation system
• Where climate risks are distributed
• Who will be most affected by extreme heat

Which hazards are the biggest threat?

Flooding poses the biggest threat, impacting all transportation infrastructure, service operations, and users. Extreme heat and severe storms impact service operations and active transportation users, also posing a threat to rail infrastructure, electrical service, and backup power.

Where are climate risks located?

Roads in urban areas are at the highest risk of flooding. Cook County has the highest percentage of roads with high or very high risk of flooding: 44 percent. There are also clusters of very high-risk road segments in Elgin, Joliet, and Waukegan.

Most of the region will experience more days of extreme heat. Annual average days over 95°F will increase from 2 to 18 by mid-century. But the largest increases — up to 20 to 25 days per year — are expected in the central and southwest parts of the region.

Where are assets most at-risk?

Of the road miles studied, 34 percent have high or very high risk, meaning they could experience up to two or more feet of flooding during a 1-in-500 chance annual storm by mid-century. Bus stops are also vulnerable, with 64 percent of CTA bus stops and 47 percent of Pace bus stops exposed to flooding.

When looking at the region’s commuter rail, 36 percent of CTA stations and 31 percent of Metra stations are at risk of flooding.

Regional trails are particularly vulnerable to flooding, since many of them follow waterways. Twenty-eight percent of regional trails have high flood risks and 33 percent have very high flood risk.

How will heat affect transit riders?

While much of the region will experience an increase in heat, it won’t affect all transit riders equally. Exposure to extreme temperatures, social and health vulnerabilities, and transit stop conditions influences heat vulnerability. When accounting for these risk factors, more than half of bus stops and rail stations have high or very high transit rider vulnerability. Urban areas in the region demonstrate higher vulnerability than non-urban areas, with higher concentrations in Chicago’s south and west sides.

How you can use this assessment

Vulnerability assessment data is available on CMAP’s Data Hub and as a map. You can use the assessment results to identify projects, inform project selection, and incorporate resilience into local planning activities like comprehensive, capital improvement, and corridor plans.

This data can also support funding applications such as the current notice of funding for Federal Highway Administration’s Promoting Resilient Operations for Transformative, Efficient, and Cost-Saving Transportation (PROTECT) discretionary grant program. CMAP encourages you to explore the vulnerability data and email Kate Evasic (kevasic@cmap.illinois.gov) with questions or comments.

Developing TRIP

Next, CMAP will develop the regional TRIP. The vulnerability assessment will help identify and prioritize projects that support resilience in the region. The full plan will be published in late 2025.

These results will also support CMAP’s long-range planning efforts and transportation programming activities. TRIP will meet the Federal Highway Administration’s PROTECT program requirements for a resilience improvement plan, positioning northeastern Illinois to compete for federal resilience funds.