Climate change is already causing more frequent road flooding, snowstorms, and heat- and cold-related pavement and communication failures. Inclement weather is currently estimated to cause 15 percent of congestion, increase the number of crashes and delays and reduce road capacity. Approximately half of the days in a typical year have weather conditions that affect driving.{{Chicago Metropolitan Agency for Planning ON TO 2050 strategy paper, “Highway Operations,” February 2017,}} Pedestrians and transit users are also affected by inclement weather, and pedestrian infrastructure is often overlooked in weather response activities.

Existing regional strategies to mitigate impacts include traveler information, alerts and advisories, vehicle restrictions such as banning trucks during high winds, road closures, snow and ice control, plowing, and pumping water from flooded locations. The Illinois Department of Transportation (IDOT), the Tollway, and Lake County report real-time “road weather” (pavement) information to TravelMidwest, but other counties currently do not. Weather responsive traffic management is also not widely used today, except for closing roads to traffic under severe conditions. As road and transit systems modernize, the same technologies that can improve system safety and reliability can make the system more responsive to weather events. The expansion of intelligent transportation system (ITS) devices and traffic management capabilities will support a variety of weather responsive traffic management strategies, such as variable speed limits to reduce speeds, updating traffic signal timing and plans to support detours and slower speeds, and increasing coverage of emergency vehicle patrols to remove disabled vehicles more quickly. In addition, as the region’s maintenance fleets become equipped with fleet management technology, opportunities for better coordination of snow and ice removal between different jurisdictions will emerge. This will reduce costs and improve the efficiency of these activities.

It will be important to collect and analyze information about how facilities perform under various severe weather scenarios so agencies can develop planned responses and better serve all users of the transportation system. For example, focusing incident management resources on locations that are known to be affected by rain or snow can reduce congestion and secondary incidents. Pavement flooding information has not been collected on a regional basis, and there is no standard pavement flooding reporting system. The impact of flooding on our roadway operations as of today is not known. This strategy also appears in the Mobility chapter under the recommendation to Improve resilience of the transportation network to weather events and climate change.

Action 1

Work toward implementing a regional, multijurisdictional traffic management center, either virtual or traditional.


CMAP, IDOT, and the Tollway

Action 2

Ensure redundant and reliable electricity and communications infrastructure and build redundancy and flexibility into planning for major transportation corridors.


Transportation agencies and utilities

Action 3

Expand ITS devices and traffic management capabilities to support weather responsive traffic management strategies.


Transportation implementers

Action 4

Coordinate snow and ice removal across jurisdictions, when possible.


Transportation implementers

Action 5

Conduct an analysis of road performance under severe weather conditions to develop planned responses.


Transportation operators

Action 6

Develop a regional pavement flooding reporting system to help plan for flood events.


CMAP and partners