Part A Process - Study Process

The first step of the Study was Part A, analyzing the existing and future conditions, and defining the purpose and needs for improvements. The tasks in Part A included collecting information on current population, employment and traffic conditions; developing geographic information system to organize and display the data; forecasting future population and employment growth in the area; predicting future travel demand, and evaluating the performance of the transportation system under future conditions. The result of this work was published as the Transportation System Performance report. With this information, IDOT identified transportation deficiencies, and started the planning process for developing local and regional solutions to address these deficiencies.

A year of collecting, forecasting, and evaluating.

The steps for Part A of the study are shown in this chart. The population and employment forecasts led to an estimate of travel demand. From this estimate, current and future transportation system performance were evaluated and resulted in the identification of transportation system needs. Public involvement was crucial throughout the entire study process.

• Data Collection/Assembly - Information to be collected in the general study area included current traffic and accident data and information on public transit, walking, bicycling and equestrian travel. Population and employment data were collected, as well as community comprehensive land use plans, zoning ordinances, and other significant development proposals. Lastly, collecting transportation plans and capital improvement programs from local, regional and state agencies was performed to learn what projects agencies are planning for the future. You and your local leaders were very involved with identifying the plans for your communities and the needs you anticipated.

• GIS/Mapping - A computerized GIS, or Geographic Information System, was used to assemble, manage and display aerial photography, environmental mapping, land use, zoning, population and employment and other relevant data.

• Population & Employment Forecasts - Population and employment forecasts were developed for the year, 2030. The population and employment forecasts were developed for the larger northeastern Illinois region, which includes Cook, DeKalb, DuPage, Grundy, Kane, Kendall, Kankakee, Lake, McHenry and Will. For this study, forecasts were also developed for LaSalle County.

• Travel Demand Forecasts - Future travel demand forecasts used the 2030 population and employment projections and used the Chicago Area Transportation Study travel demand model. The CATS model is a highly sophisticated mathematical model that uses a number of factors to forecast future travel demand. This travel demand forecast helped identify where traffic congestion will happen in the future. It also predicted how today's travel patterns will change. In late 2003, the study team completed the development of the model that replicates the existing conditions, and has developed the model for the 2030 conditions.

• Transportation System Performance - The transportation system performance analysis resulted in a detailed report on existing and future transportation conditions. Based on the 2030 population, employment, and travel forecasts, IDOT will have an understanding of travel demands and transportation system performance in the study area. This report was issued in March 2004.

• Identify Transportation Needs - Using the transportation system performance analysis report, IDOT identified what transportation needs - both local and regional - existed. The identification of transportation needs is a proactive way to address problems before they happen. This task started when the transportation system performance was evaluated.

Major milestones for Part A of the Study were the completion of the Transportation System Performance Report and the identification of transportation needs in March 2004.

The study team completed the needs assessment for the study area (Part A). Transportation deficiencies were identified that indicate the need for some type of north-south transportation improvement, so the study moved to Part B.

With deficiencies established, the study proceeded with developing the specific purpose of improvements and the needs that will be addressed. Possible solutions were evaluated by looking at preliminary alternatives that meet the purpose and need. A wide range of alternatives that could include upgrading the existing roads, new roads, public transit or a combination of improvements were identified and evaluated against the needs that were found.

The process of evaluating and selecting possible solutions to an identified need followed the federally mandated National Environmental Policy Act (NEPA) process. A Notice of Intent (NOI), which signifies the start of this process, was published on September 10, 2004 in the Federal Register.

This was a very comprehensive and complex process. In simple terms, the next step in the study was Part B. Part B was basically a screening step that began with identification of a wide range of possible solutions, and ended with the selection of alternative(s) for further detailed evaluation. Under the provisions of the National Environmental Policy Act, "reasonable alternatives," including a "no build" alternative, were objectively examined during this process.

Public involvement activity and context sensitivity continued to be applied throughout the course of the study.

Part B Process

Select the highlighted graphic buttons below (in purple) to view more information (PDF format) .

Part C Process

The further detailed evaluation of the alternatives, called Part C, included evaluation of the effects of the alternatives on the environment. These findings, in addition to the findings in Parts A and B, were reported in the Environmental Impact Statement. Part C also included further detailed evaluation of the technical factors associated with the alternatives. The technical findings were reported in the Design Report. A Draft Environmental Impact Statement (DEIS) and a Draft Design Report were prepared. Following an extensive public comment period a Final Environmental Impact Statement (FEIS) and a Final Design Report were completed that identify a preferred alternative.

The FEIS and Final Design Report defined the preferred alternative that can be developed further in final design and constructed. Prairie Parkway construction is unfunded in the FY2011-2016 Proposed Highway Improvement Program. This project will be monitored and considered for inclusion in future programs.

Part C had two major components, the EIS and Design Report. These components were developed concurrently. As the preliminary design was developed for the Design Report, there was always an awareness of the potential affect on the environment that was documented in the EIS.

As a result of the Part B screening, alternatives were carried forward for detailed study in Part C. As each alternative was developed, environmental evaluations were performed to identify, measure the possible impact, and develop possible measures to mitigate the impact on many sensitive factors. Among these many factors were context sensitivity, socio-economic, cultural, ecologic, agricultural, air and water quality, noise, natural resources, special waste, special lands, indirect and cumulative impacts.

As each alternative was developed engineering evaluations were performed to identify and measure the effect on many technical factors. Among these many factors were safety, mobility, logical beginning and end of project, access, intersection and interchange operations, river and railroad crossings, aesthetics, earthwork, cost, utilities, geotechnical, bridges, drainage, floodplains, right of way, and geometry.

A Draft Environmental Impact Statement (DEIS) and a Draft Design Report were prepared. Following an extensive public comment period, a Final Environmental Impact Statement (FEIS), and a Final Design Report were issued. The final documents define the alternative that can be developed further in final design and constructed.

General Study Area