Interstate 55 Managed Lanes

The Illinois Department of Transportation (Department) completed preliminary engineering and environmental studies (Phase I) for the improvement of I-55 from Interstate 355 (I-355) to Interstate 90/94 (I-90/94). The improvement consists of the addition of one lane along I-55 in each direction between I-355 and east of Interstate 294 (I-294) and two lanes in each direction from east of I-294 to I-90/94, the most congested portion of the I-55 corridor. These improvements will address the projected congestion through 2050. Environmental approval was received by the Federal Highway Administration in December 2018. A previous Phase I study was completed in November 2016 for one managed lane in each direction.

The study evaluated multiple alternatives for this corridor and Express Toll Lanes (ETL) showed the best improvement for traffic flow and congestion relief. The existing travel lanes along I-55 will remain free, but the new lanes are proposed to be managed as express toll lanes (ETL) with dynamic pricing to provide travel choices within the corridor. The addition of the ETL within the existing median will provide options to adapt to frequently changing traffic conditions across all lanes and provide a sustainable transportation solution. The addition of the ETL would also increase the capacity of the overall roadway. As a result, the existing travel (free) lanes would also experience reduced congestion

Note: IDOT projects typically have three distinct phases. Phase I (or the project Study) consists of developing the project scope, environmental studies and preliminary design of a project. Phase II (Design) consists of refining the design to develop contract plans and land acquisition. Phase III (Construction) consists of the actual construction of the project.