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Study Process

The I-55 Managed Lane Project is following the National Environmental Policy Act (NEPA). The Federal Highway Administration (FHWA) and Illinois Department of Transportation (IDOT) will complete an environmental study for the Managed Lane Project in order to satisfy NEPA requirements.

NEPA Process

The NEPA process requires federal agencies to integrate environmental values into their decision-making process by considering the environmental impacts of their proposed actions and reasonable alternatives to these actions. IDOT will assess the natural, built, and human environment to determine the extent of impacts that may arise from constructing and operating a project. Environmental factors such as air quality, wildlife, vegetation, water quality, wetlands, geology, neighborhoods, park/recreation areas, utilities, visual quality, and cultural resources will be assessed. NEPA encourages early and frequent coordination with the public and resource agencies throughout the project development process. Public comments that are received during the alternative analysis phase will be considered in the draft environmental document. Following NEPA guidelines, an environmental study document will be prepared and submitted for review in 2016.

Phase I Study Process

Data Collection: Assess Existing/Future Conditions

  • Data Collection
  • Identify Deficiencies
  • Identify Goals and Objectives

Purpose and Need

  • Develop Purpose and Need

Alternatives and Evaluation

  • Identify Initial Alternatives
  • Develop Evaluation Criteria

Analysis of Alternatives

  • Evaluate Alternatives
  • Identification of alternatives to be carried forward

Preferred Alternative Refinement and Documentation

  • Refine Preferred Alternative
  • Select a Preferred Alternative
  • Preparation and issuance of the environmental documentation
  • Anticipated Spring 2016


The I-55 Managed Lane Project was initiated in April of 2012 and is anticipated to be completed in 2016. Currently, this study is the only phase of the projected that is funded. Contract plan preparation and construction are not currently funded.

The Phase I study includes data collection, mainline I-55 traffic studies, traffic management analysis, preparation of base maps and mosaics, geometric studies, mapping, ground survey, select Bridge Condition Reports, cursory bridge inventory and technical memorandum, crash analysis, drainage studies, probable construction cost estimates, financial planning, and all other engineering and environmental work necessary to complete the Phase I study.