The alternatives are narrowed down through a five-step alternative evaluation process. The first three steps in the process are complete. A brief summary of each step is below.
1) Initial Screening
All of the alternatives identified above were included in the Initial Screening. The Initial Screening eliminates unrealistic or non-feasible options. Three criteria were included in this evaluation:
Does the alternative directly impact state of federally protected areas? If yes, eliminate alternative from further consideration.
Does the alternative meet the horizontal and vertical clear zone requirements for the Central Illinois Regional Airport? If no, the alternative is eliminated from further consideration.
Does the alternative divide or isolate a neighborhood or community? This criterion was assessed using guidance from IDOT’s Community Impact Assessment Manual. If yes, the alternative is eliminated from further consideration.
Thirty-six (36) alternatives were eliminated in this step due to dividing and/or isolating a community or neighborhood.
2) Purpose & Need Evaluation
The remaining 93 Build Alternatives, in addition to the East-West Only Alternative, the TSM/TDM Alternative, the Transit Alternative, and the No-Build Alternative were carried through to the Purpose and Need (P&N) Screening. The P&N Evaluation criteria are based on the Purpose and Need Statement defined for the project. Eight criteria were included in this evaluation:
Is the alternative compatible with adopted land use plans?
Does the alternative restrict/reduce opportunities for uncontrolled, or leapfrog development?
Does the alterative reduce congestion in the study area?
Does the alternative improve north/south travel efficiencies?
Does the alternative improve east/west travel efficiencies?
Does the alternative improve travel efficiency to the Interstate System?
Does the alternative improve north/south and east/west travel efficiencies to/from major travel nodes?
Does the alternate improve network wide travel efficiencies?
Eight Build Alternatives were less consistent with meeting P&N criteria and were eliminated from further consideration. The transit alternative was also eliminated at this step. The P&N Screening evaluation of the TSM/TDM Alternative is on-going and has not yet been completed.
3) Macro Analysis
The remaining 85 Build Alternatives, in addition to the East-West Only Alternative, and the No-Build Alternative were carried through to the Macro Analysis. In this step, alternatives were evaluated to ensure that those carried forward minimized impacts to the natural and human environment. Impacts to the resources were calculated for a 500 foot wide footprint for all alternatives with the exception of the East-West Only Alternative, which had a 200 foot wide footprint. Alternatives with the greatest resource impacts were eliminated in a stepwise fashion to avoid or minimize the environmental effects.
The resources considered in the Macro Analysis included the following:
Design and Traffic
Prime & Important Farmland
Safety/Percent Change in Total Crashes
Public Facilities/Access Change
Farm Tracts Severed
Farm Tracts with Access Change
Threatened & Endangered Species
Sensitive Noise Receptors within 500 feet
Other Farms Affected
Resource Impacts were assessed in three general categories. 1) Resources that were not impacted by any of the corridors under consideration. 2) Resources that were impacted equally or within the same general range by all corridors, or where only preliminary data was available. 3) Resources where impacts varied widely among corridors. Resources in the third category were considered differentiating criteria used for corridor elimination. Forty-five (45) alternatives with disproportionality high impacts to residences or prime & important farmland were eliminated during this step of the analysis. The East-West Only Alternative was eliminated in this step due to high residential impacts.
4) Alignment Analysis
The remaining 40 Build Alternatives and the No-Build Alternative were carried through to the Alignment Analysis. Impacts to the resources were calculated for a 250 foot wide footprint for all alternatives. Similar to the Macro Analysis, alternatives with the greatest resource impacts were eliminated in a stepwise fashion to avoid or minimize the environmental effects.
The resources considered in the Alignment Analysis included all those evaluated in the Macro Analysis plus these additional criteria:
Design and Traffic
Area of New Pavement
Engineering and Operational Considerations of Southern and Northern Termini Connections
Area of Farmland Consumed Outside of 2035 Land Use Plan within Alignments
Area of Total Pavement
Number of Farm Tracts Located between the 2035 Land Use Plan and Alignments
Area of Farmland Consumed Outside of 2035 Land Use Plan
Amount of Right-of-Way within Each Watershed
Highly Erodible Soils
Proximity to an Existing Bike/Pedestrian Network
Resource Impacts were assessed in three general categories similar to the Macro Analysis as described above. Residences, prime and important farmland, tract severances, farms otherwise affected, termini connections, constructability, area of new pavement, riparian areas, highly erodible soils, and bike/pedestrian access were considered differentiating criteria used to reduce the number of alignments. Through a step-wise elimination process, the forty alignments were narrowed to four. These four alignments will be carried into step five, the Environmental Assessment Analysis. To see the four remaining alignments on an interactive map click here.
5) Environmental Assessment Analysis
The Environmental Assessment is the final step of the alternative evaluation process. A detailed analysis of the remaining alternatives is conducted in this step. The single Preferred Alternative that best addresses the Purpose & Need and minimizes impacts to the socioeconomic and natural environment is identified in this step.
Did you know ...
... the majority of the future growth in Bloomington-Normal is expected to the east and south, with some growth anticipated to the west (McLean County Regional Planning Commission).
What's New ... ?
A Public Information Meeting (PIM) will be held on Wednesday, June 19, 2013 from 6:00 to 8:00 p.m. at Normal Community High School. Materials presented at the meeting will be posted to the website following the PIM.
Focus Working Group (FWG) Meetings
A summary of the Land Use and Access Management FWG and Alternative Modes FWG meetings held in early 2013 have been added. Click here to read more.
Newsletter Issue 4 was issued in December 2012. To view the newsletter, click here.
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