The Illinois State Toll Highway Authority (ISTHA) covers the northern Illinois area, a significant part of which contains northeastern Illinois, the third most congested area in the country. ISTHA provides average travel times from toll plaza to toll plaza based on "IPASS" toll transponder data collected by its electronic toll collection system. ISTHA uses data from three sources to calculate travel times: IPASS transponders; radar sensor stations along toll roads; and loop detectors maintained by the Illinois Department of Transportation. ISTHA currently posts travel times onto 33 dynamic message signs located on tolled and nearby non-tolled roads.

Although ISTHA has not conducted a formal study, emails and calls to the customer input line indicate that drivers very much approve of travel time information, and will complain when non-incident-related messages are posted at times when travel time information is normally available.