Chicago Department of Transportation Traffic Signal Planning Audit

The City of Chicago Office of Inspector General (OIG) conducted an audit of the Chicago Department of Transportation’s (CDOT) traffic signal planning practices. Traffic signals are one of the most cost-effective tools for promoting traffic safety, reducing congestion, and minimizing air pollution. CDOT is responsible for managing 2,834 signalized intersections across Chicago. The objective of the audit was to determine whether CDOT’s traffic signal planning meets industry best practices as defined by the Federal Highway Administration (FHWA). FHWA recommends that agencies have a documented traffic signal management plan with defined goals, objectives, and performance measures. The plan should also describe staff’s responsibilities and explain how they support the program’s goals and objectives. FHWA provides recommended staffing levels based on the number of traffic signals an agency manages. OIG concluded that CDOT does not have a traffic signal management plan, nor does it have objectives or performance measures connecting its traffic signal management program to broader Department goals and City plans, such as the Roadmap for the Future of Transportation and Mobility in Chicago, Vision Zero, and Chicago Streets for Cycling Plan 2020. Without a signal management plan, CDOT cannot ensure that traffic signals are optimized to promote traffic safety, reduce congestion, and minimize air pollution.