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Aug 13, 2013

Congestion Management Process

Congestion is a significant problem in our region. Decreasing the associated costs and negative impacts will require effective strategies for managing and reducing congestion throughout the transportation system.

The Congestion Management Process (CMP) is the name used nationally to describe an ongoing, systematic method of managing congestion that provides information about both system performance and potential alternatives for solving congestion-related problems. Addressing the costs of congestion is a recurring topic in the comprehensive regional plan GO TO 2040, which calls for congestion management measures as a part of strategically investing in the region's transportation system.

CMAP's use and continual development of a regional CMP will help advance the quality of life and mobility goals described in GO TO 2040. An important outcome of the CMP is a careful investigation of strategies that either directly reduce congestion or mitigate its effects by addressing related issues, such as air quality. From this, specific strategies can be selected and implemented in order to reach long term objectives set out by CMAP.

In order to be effective, the CMP incorporates extensive monitoring of the transportation network through the use of performance measures, many of which are also tracked as regional indicators. This use of data helps provide CMAP and regional decision-makers with a clear analytical understanding of congestion in northeastern Illinois.  Among other key congestion indicators, CMAP maintains freeway performance metrics and congestion scans for each segment of limited access highway in the region; a sample congestion scan is posted below.

Establishing a CMP is required by federal legislation and is governed by recently updated federal guidelines. Legislation requires that any federally-funded transportation project that significantly increases the capacity for single-occupant vehicles in our area has to be derived from a CMP.



Congestion Management Networks

CMAP works with IDOT and county governments to identify the National Highway System (NHS), eventually approved by the Federal Highway Administration.  Changes approved in 2018, as well as other NHS information, are posted on CMAP's NHS page.  A NHS map was prepared in the fall of 2018 to reflect 2018 changes in the National Highway System: 2018 National Highway System Map for the Chicago Region.  

CMAP, working with the Regional Transportation Operations Coalition, has also identified a network of highways critical for the region's mobility, and on which we should focus regional performance measurement activities.  This network, consisting of the NHS and the Strategic Regional Arterial System, includes all regional expressways, other principal arterials, and NHS intermodal connectors.

In addition, the CMP also identifies a freight rail network, consisting of rail mainlines with six or more estimated freight trains per day, CREATE Program Corridors, and CREATE Program highway-rail grade separations.  The CMP transit service network consists of rail and bus service operated by Metra, the Chicago Transit Authority, and Pace Suburban Bus Service, including planned bus rapid transit and express bus services.

Interactive Mobility Visualizations

Explore interactive mobility data visualizations on how congestion management can affect metropolitan Chicago's transportation system. 

Key Congestion Management Strategies

The Chicago Metropolitan Agency for Planning's CMP includes the following key strategies and processes from GO TO 2040, the region's comprehensive regional plan:

  • Performance-based funding.  CMAP is developing performance measures, internal processes, and partnerships with other agencies to assure that transportation funds are not allocated based on arbitrary formulas, but on performance data.  A performance-based funding system will be more likely to identify and mitigate highway congestion than fixed allocation processes.  CMAP is committed to working with implementers to develop a transparent programming process that allocates funding efficiently to maintain a world-class multi-modal transportation system.  A more transparent, more effective funding system will facilitate requests for improved revenue to address identified deficiencies: taxpayers will support investing in a transportation system that improves their quality of life, that brings jobs and prosperity, and that spends money wisely.  See
  • Congestion Pricing.  CMAP's GO TO 2040 Plan recommends the implementation of congestion pricing to manage traffic and to offer travelers more choices.  Congestion pricing uses a market-based approach so as to improve system performance while strategically raising limited revenues.  When implemented as express toll lanes, congestion pricing will enhance the economy, provide traveler choices, reduce travel time and improve travel time reliability, among other benefits.  More information about congestion pricing and CMAP's plans for express toll lanes is at

Process Documentation and Report Archive

Congestion Management Documentation. Draft, January, 2013.  (PDF, 5MB).  The document includes the introduction and sections on objectives, area and systems of application, performance measures, and monitoring plans. 

Congestion Management Report Archive

The Congestion Management System (PDF, 2MB) lay out the Congestion Management System for northeastern Illinois as developed under ISTEA, the prior federal transportation authorization legislation.

The Congestion Management System Technical Supplement (PDF, 5MB) provides greater detail about the process.

Transportation Demand Management Strategies  (March, 2009).  This paper reviews the effects of strategies to reduce Transportation demand, including additional pricing strategies not included in our Managed Lanes overview.

Arterial Strategies Part 3a: Roundabouts (Draft, January, 2009).  This paper reviews the effects of roundabouts.  The paper reviews the safety and operation benefits of roundabouts, as well as several drawbacks.

Security and Emergency Management Strategies (November, 2008).  This GO TO 2040 strategy paper, prepared for CMAP by the Volpe Center, reviews security and emergency management planning options for MPOs.

Arterial Strategies Parts 1 and 2: Pavement Cross-Sections and Access Management (Final, January 2009)  This paper reviews arterial-related strategies and their potential impacts, focusing on pavement cross-sections and access management.

Congestion Mitigation Handbook (pdf 820KB) 1998

Airports Trip Generation (pdf 1.6MB) 2007

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