Chicago Department of Transportation Traffic Signal Planning Audit Follow-Up

The City of Chicago Office of Inspector General (OIG) has completed a follow-up to its June 2020 audit of the Chicago Department of Transportation’s (CDOT) traffic signal planning practices. Based on the Department’s responses, OIG concludes that CDOT has fully implemented one of three corrective actions related to the audit finding, substantially implemented another, and partially implemented the third.

The purpose of the 2020 audit was to determine whether CDOT’s traffic signal planning met industry best practices as defined by the Federal Highway Administration (FHWA). Our audit found that CDOT did not have a traffic signal management plan, objectives, or performance measures connecting its traffic signal management program to broader Department goals and City plans.

Based on the results of the audit, OIG recommended that CDOT develop a traffic signal management plan aligned with FHWA recommendations, including clear goals and objectives, performance measures, and a strategy to transition toward more proactive signal maintenance and retiming work. OIG also recommended that the Department conduct an analysis to determine its staffing needs related to traffic signals and work with the Office of Budget and Management to meet those needs. In its response to the audit, CDOT described corrective actions it would take.

In December 2021, OIG inquired about corrective actions taken by CDOT in response to the audit. Based on CDOT’s follow-up response, OIG concludes that CDOT has substantially implemented one corrective action, fully implemented another, and partially implemented the third. Specifically, CDOT has drafted a traffic signal management plan—with assistance from each of its relevant divisions—but the plan lacks recommended elements, such as targets, and has not yet been published. Finally, CDOT has not yet performed a staffing analysis, but plans to do so in 2022.

Once fully implemented, OIG believes the corrective actions reported by CDOT may reasonably be expected to resolve the finding noted in the audit. We urge the Department to publish its traffic signal management plan and complete its staffing analysis for the traffic signal program.