I-88/Illinois Route 47 Full Interchange - Sugar Grove ... · PDF fileI-88/Illinois Route 47...

Interchange Feasibility Study I-88/Illinois Route 47 Full Interchange Kane County, IL Prepared for Village of Sugar Grove, Illinois August 5, 2010 Prepared by GRAEF 8501 West Higgins Road, Suite 280 Chicago, Illinois 60631-2801 Telephone: (773) 399-0112 FAX: (773) 399-0170 www.graef-usa.com

Village of Sugar Grove Interchange Feasibility Study I-88/IL Rte. 47 Full Interchange

Table of Contents- Page i

TABLE OF CONTENTS EXECUTIVE SUMMARY Page No. 1-4 1.0 INTRODUCTION Page No. 5-10

1.1 Purpose of the Study 1.2 Report Organization 1.3 History of the Project 1.4 Previous Reports 1.5 Description of the Study Area 1.6 Project Scope 1.7 Study Limitations 1.8 Acknowledgements

2.0 PURPOSE AND NEED Page No. 11-12

2.1 Traffic Benefit 2.2 Social and Economic Demands 2.3 Interchange Spacing Requirements

3.0 EXISTING CONDITIONS Page No. 13-16

3.1 Traffic 3.2 Roadway 3.3 Lighting 3.4 Structural 3.5 Existing Utilities 3.6 Land Use 3.7 Existing Right-of-Way 3.8 Environmental Conditions

4.0 INTERCHANGE LAYOUTS Page No. 17-27

4.1 Option 1 – Conventional Diamond Interchange 4.2 Option 2 – Northeast Loop Ramp 4.3 Option 3 – Eastbound I-88 Loop Off-Ramp 4.4 Option 4 – Single Point Urban Interchange (SPUI) 4.5 Option 5 – Diverging Diamond Interchange 4.6 Option 6 - No-Build Alternative 4.7 Feasibility Discussion 4.8 Ultimate Interchange Alternates 4.9 AET (All Electronic Tolling) vs. Cash Tolling

5.0 TRAFFIC EVALUATION OF INTERCHANGE DESIGN ALTERNATIVES Page No. 28-33

5.1 Projected Traffic Volumes 5.2 Traffic Analysis of the System 5.3 Access Control Limitations

6.0 COMPATIBILITY WITH LOCAL AND REGIONAL PLANNING Page No. 34-36

6.1 Design Standards 6.2 Support of Local Jurisdictions and Regional Planning Agencies 6.3 Compatibility with Local and Regional Planning

7.0 PROJECT COST AND POTENTIAL FUNDING SOURCES Page No. 37

7.1 Probable Cost of Construction 7.2 Potential Funding Sources


Table of Contents- Page ii

8.0 CONCLUSION Page No. 38-39

8.1 Impetus for the Interchange 8.2 Recommended Interchange Configuration 8.3 Next Steps

APPENDICES Appendix A Environmental Analysis for Interchange Study at Interstate Route 88 and Illinois

Rte 47 Appendix B Illinois Tollway and IDOT Geometric Design Criteria Appendix C Toll Plaza Design Criteria Appendix D Agency Meeting Correspondence Appendix E Interchange Volumes Study Appendix F HCS Worksheets and Synchro Reports

o F-I Existing Freeway Capacity Reports o F-II Existing Ramp Capacity Reports o F-III Existing Intersection Capacity Reports o F-IV 2020 Freeway Capacity Reports o F-V 2020 Ramp Capacity Reports o F-VI 2020 AM – Diamond Interchange Capacity Report o F-VII 2020 PM – Diamond Interchange Capacity Report o F-VIII 2030 Freeway Capacity Reports o F-IX 2030 Ramp Capacity Reports o F-X 2030 AM – Diamond Interchange Capacity Report o F-XI 2030 PM – Diamond Interchange Capacity Report o F-XII 2030 AM – Northeast Loop Ramp Interchange Capacity Report o F-XIII 2030 PM – Northeast Loop Ramp Interchange Capacity Report o F-XIV 2030 AM – SPUI Interchange Capacity Report o F-XV 2030 PM – SPUI Interchange Capacity Report o F-XVI 2030 AM – DDI Interchange Capacity Report o F-XVII 2030 PM – DDI Interchange Capacity Report o F-XVIII 2030 AM – Finley Three-Quarter Access Capacity Report o F-XIX 2030 PM – Finley Three-Quarter Access Capacity Report o F-XX 2030 AM – DDI Interchange Capacity Report o F-XXI 2030 PM – DDI Interchange Capacity Report

Appendix G Agency Correspondence o G-I Single vs. Dual Left-Turn Lane Evaluation

Appendix H Support Resolutions of Local Jurisdictions Appendix I Construction Cost Analysis

o I-I Project Unit Cost Development o I-II Conventional Diamond Interchange Detailed Cost Estimate o I-III Northeast Loop Ramp Interchange Detailed Cost Estimate o I-IV Single Point Urban Interchange Detailed Cost Estimate o I-V Diverging Diamond Interchange Detailed Cost Estimate

Appendix J Zoning and Transportation Maps o Village of Sugar Grove – 2008 Zoning Map o Village of Sugar Grove – Future Land Use Plan o Village of Elburn – Zoning District Map o Village of Sugar Grove – Transportation Plans o Illinois 47 Corridor Study – Capitol Improvements & Proposed SRA Cross

Section Appendix K Previous Reports – I-88/Illinois Rte. 47 Interchange Completion Analysis,

CEMCON, Ltd.


Table of Contents- Page iii

EXHIBITS Exhibit 1 2030 Conventional Diamond Interchange Exhibit 2 2030 Diamond Interchange with NE Loop Ramp Exhibit 3 2030 Single Point Urban Interchange (SPUI) Exhibit 4 2030 Diverging Diamond Interchange Exhibit 5 Existing Half Diamond Interchange Exhibit 6 Illinois Route 47 Access Control Exhibit Exhibit 7 Diamond & NE Loop Ramp Interchange Design ROW Display Exhibit 8 SPUI Interchange Design ROW Display Exhibit 9 Diverging Diamond Interchange Design ROW Display Exhibit 10 I-88 at IL Rte 47 Existing Bridge Section Exhibit 11 Illinois Route 47 Proposed Typical Sections Exhibit 12 Ramp Typical Sections Exhibit 13 2030 Seavey Road Design after Redevelopment Exhibit 14 2030 Conventional Diamond Interchange – Cash and IPass Tolling Option Exhibit 15 2030 Conventional Diamond Interchange – Alternate Suburban Design Exhibit 16 Diamond Interchange Design ROW Display - Alternate Suburban Design Exhibit 17 Illinois Route 47 Proposed Typical Sections – Alternate Suburban Design Exhibit 18 Finley Road NB Left Sight Distance

Village of Sugar Grove IL RTE 47/I-88 Interchange Feasibility Study

1

IL RTE 47/I-88 INTERCHANGE FEASIBILITY STUDY EXECUTIVE SUMMARY 1. PROJECT IDENTIFICATION The “I-88/Illinois Route 47 Full Interchange Feasibility Study” has been prepared to provide an analysis and evaluation of several interchange configurations. The Village of Sugar Grove is the lead agency for the study with significant financial support from Crown Community Development. All options consider adding ramps to and from the east, as the Village of Sugar Grove desires to investigate the feasibility of a full interchange. The investigation presented herein provides several alternatives for the proposed improvements. Of the five alternates investigated for a full service interchange at IL Rte. 47, the alternate deemed most feasible under the operational and financial constraints of the project is the Conventional Diamond Interchange. The purpose of this report is to assess the conditions of the project location, analyze existing and projected (2020 & 2030) traffic, and identify feasible designs for use in future phases of study. The next step in the project would be the development of a Phase I Report. The project is located in southern Kane County in Blackberry Township. The Village of Sugar Grove is located south of the interchange and the Village of Elburn is located to the north. The interchange is located at milepost 109.5 on the Reagan Memorial Tollway (I-88). This is approximately 15.5 miles east of the Peace Road interchange and 4 miles west of the IL Rte. 56 system interchange. The project will include the addition of ramps to and from the east, as well as a partial reconstruction of the existing ramps to and from the west. New toll plazas are proposed to be constructed on all ramps of the proposed interchange. The purpose of the project is to provide a safe full access facility that will improve connectivity to the interstate network while also meeting the development goals of the adjacent communities. Planning documents from the Village of Sugar Grove, Village of Elburn, and the Chicago Metropolitan Agency for Planning (CMAP) indicate a tremendous potential for residential and commercial/industrial development with associated traffic growth in the project area over the next several years. This facility will help to address the inappropriate usage of local roadways by regional traffic. Kane County supports the full interchange as integral to their land use and transportation planning, as evidenced by their Long Range Transportation plan. Record drawings, highway plats, aerial photography, contour mapping, and utility atlases were utilized to develop existing conditions presented in the report exhibits. 2. RESULTS OF THE INVESTIGATON The major design characteristics addressed in this report include: Environmental Impacts, Existing Infrastructure Impacts, Traffic Operations, Roadside Safety, Toll Plaza Locations and Operations, Right-of-Way Acquisition, and Project Cost. These design characteristics are not listed in order of importance. Environmental Impacts: Environmental issues are addressed in Section 3.8 and Appendix A. Issues addressed include wetlands, water quality, floodplains, threatened and endangered species, and potential hazardous materials. Nothing in the environmental investigation precludes the development of the full service interchange. Existing Infrastructure Impacts: The infrastructure being evaluated includes IL Rte. 47, the Reagan Memorial Tollway, and the existing IL Rte. 47 Bridge over I-88. An inventory of roadway lighting and utilities was also included. Significant reconstruction of the aforementioned roadways


2

will be necessary. Fiber optic cables, electrical lines, telephone lines, and gas facilities all exist within the project area. No significant impacts to existing utilities are anticipated with the construction. Please see Section 3.5 for information regarding existing utilities in the project vicinity. Traffic Operations: The geometry of the existing I-88/IL Rte. 47 Interchange is a half diamond interchange with ramps connecting I-88 Eastbound to Rte. 47 and Rte. 47 to I-88 Westbound. The current design arrangement does not allow traffic movements from Rte. 47 to I-88 Eastbound or from I-88 Westbound to Rte. 47. This configuration does not meet motorists’ expectations for full service interchange. All of the full interchange designs considered in this study are expected to provide sufficient capacity to manage traffic volumes projected through the 2030 design year. The Eastbound I-88 Loop Off-Ramp alternative was eliminated based on feedback from agency staff. The No-Build alternative is not recommended, as it does not meet driver expectation or the long-term transportation goals of local and regional jurisdictions. The Diverging Diamond is not expected to function as well as the Conventional Diamond, NE Loop Ramp, or the SPUI from a traffic operations standpoint. The purpose of the project is to provide a safe roadway that will improve connectivity to the interstate network while meeting the development goals of the impacted communities. Phase I engineering will document the impacts and cost of each viable alternative and the results will be coordinated with the public prior to finalizing an interchange type. Roadside Safety: The incorporation of agency design criteria and typical standards will minimize accident potential. Addressing specific roadside obstacles and hazard mitigation will continue in Phase I of the project design. Toll Plaza Locations and Operations: For all design alternatives under consideration, the new toll plazas will be located on all ramps to and from Interstate 88. Appropriate Tollway communication infrastructure will be included in the plaza design. Right-of-Way Acquisition: The right-of-way required for each alternative varies from the extreme of over eleven acres for the Eastbound I-88 Loop Off-Ramp to zero acres for the No-Build option. However, the remaining alternatives are more closely aligned and fall within the proximity of less than two acres. The SPUI and DDI necessitate slightly less acreage (average of 1.6 acres) than the Conventional Diamond or the NE Loop Ramp (average of 2.7 acres). The majority of the subject right-of-way is owned by Crown Community Development. This land developer is in firm support of the proposed interchange. The remainder of land, not owned by CCD, is owned by another developer who also supports this project. Project Cost: The total project cost includes the cost of construction, right-of-way acquisition, utility relocations and engineering. With the exception of the No-Build option, the Conventional Diamond Interchange has the lowest probable project cost of $19.7 million in 2009 dollars. The highest projected cost is $32.3 million for the SPUI Alternative. An overall summary of the project costs is shown on Table 4-1. 3. CURRENT AND FUTURE SRA STATUS The recently completed IL Rte. 47 Corridor Study by Kane County shows the Existing Development Context Zones along IL Rte. 47 as Open Space/Agricultural and Residential from north of the IL Rte. 47/I-88 interchange south to Scott/Denny Road. This appears to have been a prime consideration in the 1995 IDOT Strategic Regional Arterial (SRA) Study for IL Rte. 47 which classifies this section of the IL Rte. 47 corridor as a “Rural SRA” from just south of Bliss Road to north of Seavey Road.


3

However, that SRA report is now 15 years old and the Village of Sugar Grove is identified by Kane County as a “Priority Place”, which is defined as a center where safe, healthy and livable communities can be developed through implementation of smart growth principles. The Village has significant potential for additional retail space and the Kane County IL Rte. 47 Corridor Study now identifies the IL Rte. 47 corridor from north of Seavey to US 30 as primarily future suburban Commercial and Residential. The timing of the build-out for the subject corridor within Sugar Grove will likely coincide with the completion of a full interchange at I-88 and IL Rte. 47. Accordingly, the Kane County study has noted that the proposed right-of-way (ROW) needs and cross-sections for IL Rte. 47, as based on the 1995 IDOT IL Rte. 47 SRA Report, may no longer reflect current conditions and planned land use nor be appropriate based on the Development Context Zones identified by the Village of Sugar Grove. At the request of IDOT representatives reviewing the Feasibility Study, and for purposes of guidance on ROW preservation and protection, this interchange feasibility study has taken a conservative approach and based preliminary IL Rte. 47 improvements on design parameters for the wide-median and high speed (60 mph design speed) “Rural” SRA cross-section. A lower design speed (50 mph) and narrower median suburban design, however, has been included in Exhibits 15, 16, and 17. It is the intent of the Village of Sugar Grove to pursue this “Suburban” design treatment, which is more compatible with local development context and pedestrian/bicycle accessibility and significantly reduces project cost, as the interchange project proceeds to Phase I (design) engineering. 4. CONCLUSION A standard conventional diamond interchange with a four-lane IL Rte. 47 section is sufficient to accommodate 2020 and 2030 traffic projections. The 2030 design is in the scope of the Feasibility Study and is the previously agreed upon timeframe as discussed with the Illinois Tollway and the Illinois Department of Transportation (IDOT). After agency approval of the Feasibility Study, the next step in the project will be the Phase I Study. The Phase I Study likely will require preferred interchange design options and a cost/benefit analysis of alternates for a design year consistent with CMAP’s most up-to-date projections. A full service interchange at IL Rte. 47 meets the purpose of the project, which is to provide a safe full access facility that will improve connectivity to the interstate network while meeting the development goals of the local communities. Governmental and commercial entities in the vicinity of the interchange have expressed their support for the full interchange. Six alternatives (including a “No-Build” option) were evaluated during this feasibility study and our conclusions are as follows. The conventional diamond interchange requires minimal right-of-way and has the lowest project cost of the alternatives investigated in the study. Reconstruction and widening of IL Rte. 47 will be necessary, as well as signalized intersections to accommodate the new ramps, both north and south of the interchange. This alternative allows for the existing bridge, which had its superstructure fully reconstructed in 2007, to remain. The conventional diamond interchange is a viable option and will be strongly considered in the next phase of design. The NE Loop Ramp alternative eliminates the northbound left turn at the Westbound I-88 ramp. This will provide an increase in overall capacity over the conventional diamond interchange and eliminate back to back left turns on the bridge. However, this design also requires additional right-of-way and an increased cost of construction. The existing bridge will be impacted and some modifications to the structure will be required to configure the north span properly for the new ramps. The existing Illinois Tollway storage yard in the northeast quandrant will also need to be relocated for this configuration to be feasible. The NE Loop Ramp Alternative is considered a viable option and will be further studied in the next phase of design.


4

The Eastbound I-88 Loop Off-Ramp was considered in the early phases of this study. However, this alternative was not pursued further because it requires substandard geometry which would not meet the minimum standards of AASHTO or FHWA. This alternative will not be considered in the subsequent phase of design. The SPUI alternative is an efficient single-point design that provides adequate capacity for all movements. It is also the safest alternative due to the reduction in conflict points and requires the least amount of right-of-way. Conversely, the SPUI Option has the highest cost at $32.3 million. This alternative will require a complete reconstruction of the existing bridge, which was recently upgraded in 2007. Complete reconstruction of the bridge will lead to the longest construction duration of any alternative. Although this alternative has some major drawbacks, it is still a viable option due to its capacity and safety characteristics. The DDI alternative is a fairly new interchange design that has not been widely used in the United States. The main argument supporting DDI interchanges is that they completely eliminate left-turn conflict points. However, the main argument against DDI interchanges is that they force motorists to drive through the interchange on the left side of the road. This non-standard design could lead to driver confusion and potential wrong-way turning movements. Overall, the design has a low cost, minimal right-of-way acquisition, and the existing bridge can be maintained with minimal construction. The DDI is a feasible option which will be further studied in the subsequent phase. As noted in the evaluation matrix (Table 4-1), there are several designs that provide the capacity and safety requirements for the new I-88/Rte. 47 Interchange. In Phase I, these factors will be further evaluated and comments/suggestions from IDOT and the Illinois Tollway will be integrated into the proposed design.


5

INTRODUCTION 1.1 Purpose of the Study

The purpose of this Interchange Feasibility Study is to provide the relevant analysis for alternative layouts of a full service interchange on Interstate 88 at Illinois Rte. 47 in southern Kane County, Illinois. Additionally, all viable alternatives identified must accommodate year 2030 traffic projections. The study is required by the Illinois Tollway and IDOT in order to obtain the next level of support from the Agencies. As limited resources and unfunded operational needs prohibit both the Illinois Tollway and IDOT from initiating new facilities, specific high interest projects are typically locally initiated and jointly developed. The Village of Sugar Grove has notified the regional transportation agencies (Illinois Tollway, IDOT, CMAP and Kane County) of the desire to proceed with this project and to serve as lead agency in its development. This feasibility study sets the stage for the remainder of the preliminary engineering and the final engineering phases. This report will be the primary resource for the subsequent development of a Phase I report and Phase II construction documents. The goal of the study is to obtain concurrence on feasible interchange designs from the affected transportation agencies and enhance the opportunity for construction funding. The Illinois Tollway requires a minimum design horizon of 10 years.

1.2 Report Organization

The report follows the policy established by the November 2007 Illinois Tollway report titled Illinois Tollway Interchange and Roadway Cost Sharing Policy, and Section 4.4 of the June 2006 Illinois Tollway Design Section Engineer’s Manual. The following summarizes the Illinois Tollway requirements as applicable (Items to be addressed in the report are indicated with bold type): Identify the Project Need (Traffic Benefit, Economic Development Benefit,

Alternatives Analysis and Local Support) Complete a Traffic Analysis Report based on 20-year traffic projections. Prepare an Access Justification Report as required by the Illinois Department of

Transportation and/or Federal Highway Administration. Environmental Analysis of project impacts and mitigations of affected resources. Noise Analysis Determine required right-of-way and access control limits. Determine construction and right-of-way access control costs.

1.3 History of the Project A full service interchange at IL Rte. 47 has been in the planning or concept stage for a number of years. In 1994 the Illinois Tollway prepared construction plans for conversion of the interchange to a full service conventional diamond interchange by adding ramps to and from the east. However, this project was not constructed due to funding shortfalls and other priorities. Ramps to and from the east at IL Rte. 47 are included in the Kane County 2030 Transportation Plan, Village of Sugar Grove Transportation Planning Study, and the 2004 Kane County Transportation Planning Area Study. The full service interchange is also supported by CMAP and is a critical component of the recently completed IL Rte. 47 Corridor Plan prepared by Kane County.


6

In 2008 the Village of Sugar Grove enlisted the project team of GRAEF, Metro Transportation Group, and Huff & Huff, Inc. to prepare an Interchange Feasibility Study for a full service interchange at the existing I-88 and IL Rte. 47 half-diamond interchange.

1.4 Previous Reports Crown Community Development retained CEMCON, Ltd. to provide an analysis for the conversion of the IL Rte. 47 interchange at I-88 to a full service interchange. This report, titled I-88/Illinois Rte. 47 Interchange Completion Analysis, is dated June 28, 2006 and recommends several alternatives for the proposed interchange improvements including a full diamond interchange and a Partial Cloverleaf/Partial Diamond interchange. 1.5 Description of the Study Area The interchange being studied is located in southern Kane County in Blackberry Township between the Village of Elburn north of the interchange and the Village of Sugar Grove south of the interchange. The general Kane County roadway network is shown in Figure 1-1. Geometric improvements for the Interchange Feasibility Study specifically focus on I-88 between Blackberry Creek located 1 mile south of the Tollway Mainline and Seavey Road located 0.5 mile north of the Tollway Mainline. The study area for traffic projections in this Interchange Feasibility Study includes I-88 between IL Rte. 56 and the Main Street crossing of the interstate and on IL Rte. 47 between Galena Road to the south and Keslinger Road to the north. The specific study boundary is shown in Figure 1-2. Figure 1-3 provides aerial photography of the existing IL Rte. 47 interchange.


7

Figure 1-1 Kane County Transportation Overview


8

Figure 1-2 Interchange Study Boundaries

Figure 1-3 Project Location


9

1.6 Project Scope This study investigates alternative full service interchange configurations and their impacts on IL Rte. 47 and I-88. Currently, access is only provided at IL Rte. 47 for I-88 mainline traffic traveling to and from the west. Five interchange configurations for a full service interchange for IL Rte. 47 at I-88 have been considered herein. The interchange configurations include a Conventional Diamond, an I-88 Eastbound Loop Off-Ramp, a Northeast Loop Ramp, a Single-Point Urban Interchange (SPUI), and a Diverging Diamond Interchange. GRAEF’s sub-consultants, Metro Transportation Group, Inc. and Traffic Analysis & Design, Inc., developed projected traffic data with input from regional and local jurisdictional agencies and proposed development plans. These projections were utilized to examine traffic operation and develop the geometrics of the feasible interchange configurations. Design provisions, including number of turn lanes and turn bay storage lengths, were developed based on the traffic analysis. Impacts to existing environmental resources have been evaluated. Features including wetlands, archeologically significant areas, water resources, previously contaminated sites, and agricultural land have been identified and evaluated. The goal is to minimize environmental impacts while maintaining the desired functionality of the interchange. Presently, there are no known environmental factors which would limit or preclude the completion of the project. Coordination with the resource agencies will be initiated in the Phase I process. This is an important element in assessing alternatives, particularly when avoiding potential Threatened and Endangered (T&E) species. T&E issues need to be resolved in the Phase I Study. Additional coordination may be needed in Phase II permitting and Phase III construction depending on the species involved and extent of impacts. Impacts to the existing utilities have been evaluated. Existing utilities have been identified using the following sources: topographic survey, utility company atlases, and Tollway permit records. 1.7 Study Limitations Access locations for proposed developments and improvements to Seavey Road are addressed in this Interchange Feasibility Study. As part of the land dedication process, Crown Community Development will be seeking Tollway and IDOT cooperation for access north of I-88 and south of Seavey Road as indicated on Exhibit 1. The east access would reduce queuing and delay for the northbound right-turning movement on IL Rte. 47 at Seavey Road. Access locations for any proposed developments will be addressed in the IDOT permitting process for the IL Rte. 47 access modifications. No waivers from standard IDOT Access Control Distances are anticipated for these proposed locations. It is anticipated that improvements to Seavey Road will be identified as a part of the IDOT permitting process for the planned Crown Community Development site, given this roadway’s role as a primary point of access for parts of the Crown development. Traffic projections indicate that IL Rte. 47 may eventually have to expand between the existing I-88 interchange and the existing section at Old Oaks Road to accommodate future traffic volumes. See Appendix J for information regarding the IDOT Route 47 corridor study. Reductions in anticipated development of adjacent properties will not impact the need for a full service interchange at IL Rte. 47 and I-88.


10

1.8 Acknowledgements This report has been prepared under the Agreement with Village of Sugar Grove, IL and GRAEF. Portions of this report have been developed by other consulting firms acting as sub-consultants to GRAEF. They include:

Huff & Huff, Inc. 915 Harger Road, Suite 330 Oak Brook, IL 60525

Metro Transportation Group, Inc. 3100 W. Higgins Road, Suite 100 Hoffman Estates, IL 60169

Traffic Analysis & Design, Inc., (TADI) 1898 Waverly Way Montgomery, IL 60538


11

PROJECT NEED 2.1 Traffic Benefit I-88 serves as a regional transportation corridor extending from the Quad Cities area of Illinois and Iowa to the Chicago metropolitan area. Existing access at IL Rte. 47 provides access only to/from the west. No direct access to/from the east to I-88 is available and this traffic must now access I-88 at IL Rte. 56 (4 miles east), Orchard Road (5 miles east), or Peace Road (15.5 miles west). This restricted access is not compatible with growth demands of the Village of Sugar Grove, Village of Elburn, and southern Kane County. IL Rte. 47 is a designated Strategic Regional Arterial (SRA) Route and part of the approximately 1,300-mile SRA system intended to provide a safe and operationally effective level of service along high volume arterial roadways. The purpose of Strategic Regional Arterial routes is to supplement the existing expressway system by providing local arterials with high mobility for regional travel. IL Rte. 47 is also a Class II Truck route, serving north-south truck trips between Interstates 55, 80, 88, 90, and Wisconsin. A full access interchange at Interstate 88 and IL Rte. 47 is consistent with regional transportation plans such as those identified and recommended in IDOT’s SRA Report for IL Rte. 47, the Kane County 2030 Transportation Plan, Village of Sugar Grove Transportation Planning Study, the 2004 Kane County Transportation Planning Area Study, and the Illinois 47 Corridor Plan that was recently completed by Kane County. CMAP has also commented favorably on completion of this interchange (see page 38). Without east ramps at IL Rte. 47, the nearest access points to I-88 to and from the east are located at Illinois Route 56 and at Orchard Road (located four and five miles east of IL Rte. 47, respectively). For motorists with origins or destinations south of I-88, IL Rte. 56 is the most proximate and can be accessed from IL Rte. 47 roughly four miles south of the I-88 interchange. Vehicles traveling to and from areas north of I-88 likely utilize Orchard Road by way of local roadways such as Seavey Road, Main Street, Keslinger Road, and Randall Road. Each of these paths to the Orchard Road interchange are primarily comprised of rural, two-lane roadways and do not provide direct access to the desired interchange. The addition of ramps to and from the east at IL Rte. 47 would provide improved interstate access to areas north of I-88 (particularly the Villages of Elburn and Kaneville), thereby reducing traffic on the local roadways currently used to travel to and from the Orchard Road interchange. As development trends continue to extend radially from the Chicago core, increasing pressure is placed on the existing transportation network. Access to and from regional systems such as I-88 is essential to the economic vitality and maintenance of quality of life standards in developing communities and to prevent the local roadway system from serving regional traffic for which it was not designed. The Villages of Sugar Grove and Elburn have experienced high growth rates in recent years as development trends begin to occur along IL Rte. 47 and southern Kane County. In 2000, the Village of Sugar Grove had a population base of 3,909. In a special census performed in 2005, that population base had expanded to 7,958, an annual growth rate of over 15 percent. The Northern Illinois Planning Commission (NIPC) has projected that Sugar Grove’s population will increase to 62,742 by 2030. Sugar Grove’s 2008 Zoning Map and Land Use Plan from the Village’s Comprehensive Plan are included in Appendix J. In 2000, the Village of Elburn had a population of 2,756. In a special census preformed in 2006, that population base had expanded to 4,721, an annual growth rate of over 9 percent. The Northern Illinois Planning Commission (NIPC) has projected that Elburn’s population will increase to 21,126 by 2030. Elburn’s Zoning District Map is included in Appendix J.


12

This growth in population will presumably be accompanied by a proportional expansion of complementary retail and commercial developments, further adding to the demand on the transportation network. Communities north and south of the interchange area are expected to see similar growth patterns, creating a regional demand for improved interstate access. The growth projections within the Villages of Sugar Grove and Elburn and the prospect of similar growth patterns in neighboring communities, coupled with the limited interstate access alternatives, focus a significant portion of the regional trip-making at the I-88/IL Rte. 47 interchange. Projections have been developed (see Appendix E) which highlight the significant increase in travel demand which is expected to take place in this location. 2.2 Social and Economic Demands Efficient access to regional routes is essential to accommodate the growth and development that is planned for this region. In addition, providing full freeway access to the Tollway system will assist in alleviating traffic congestion on the regional roadway network and the existing interchanges located upstream and downstream of the IL Rte. 47 interchange. Additionally, the proposed interchange improvements will help accommodate traffic continuing north following the construction of the Prairie Parkway. The reconstruction of the existing half diamond interchange to a full access interchange is a high priority transportation project that facilitates economic development in the region and improves the distribution of regional traffic in rapidly growing southern Kane County. The local communities of the Village of Sugar Grove and the Village of Elburn recognize that a full interchange improvement will accommodate the traffic demand created by their development plans, which will create more employment opportunities within the region. 2.3 Interchange Spacing Requirements Analysis of agency interchange spacing requirements looked at the IL Rte. 47 to Peace Road freeway segment (15.5 miles west) and the IL Rte. 47 to IL Rte. 56 segment (4 miles east). Illinois Tollway Requirements Minimum interchange spacing required is 2 miles on the Tollway. The following existing and future conditions along the Tollway system have been considered in establishing the minimum spacing:

Balancing the need for an interchange with maintaining the basic function of the Tollway mainline system.

Traffic conflicts caused by high traffic demand on mainline and at an interchange. Limited Funds. Mainline Plaza capacity and operation.

The addition of ramps to and from the east on Interstate 88 would meet the minimum and desired spacing design criteria for Illinois Tollway. Please note that it would also meet IDOT and FHWA minimum spacing criteria for a rural area (3 miles between interchanges).


13

3.0 EXISTING CONDITIONS 3.1 Traffic In order to evaluate traffic operations at the existing subject interchange, peak hour turning movements and daily traffic counts were collected within the primary study area (depicted in Figure 1 of Appendix E). To supplement this data, letters were sent to various jurisdictional transportation agencies (including IDOT, Illinois Tollway, CMAP, KDOT, and the Villages of Sugar Grove and Elburn) requesting historical traffic data, future traffic projections, area development plans, and other traffic-related information for the interchange influence area. All available traffic data was combined to develop the existing traffic networks, as shown in Figures 2 and 3 in Appendix E. Based on 2008 data collection, mainline I-88 currently carries approximately 28,000 vehicles per day east of IL Rte. 47, with bidirectional volumes of roughly 2,000 to 2,500 during the weekday morning and evening peak hours. The eastbound exit ramp at I-88/IL Rte. 47 has a peak hour utilization of roughly 125 vehicles in the morning and evening and an Average Daily Traffic (ADT) count of nearly 2,000. On the westbound entrance ramp, peak hour traffic volumes were observed at between 150 and 200 in the morning and evening; ADT on this ramp is approximately 1,800. Vehicles entering and exiting the mainline Tollway at IL Rte. 47 (the only interchange with access to and from the west within a stretch of 20 miles) make up between 10 and 15 percent of I-88 traffic to and from the west. Using HCS+ software, existing traffic operation was evaluated for the study intersections and Tollway system. The resulting Level of Service (LOS) data is shown in Table 3-1. Table 3-1 – EXISTING CONDITIONS – CAPACITY ANALYSIS1

1Because all study intersections are currently unsignalized, overall intersection levels of service are not reported by HCS+. 2Levels of service for the major leg’s opposed left-turning movements are reported first, while levels of service for the minor leg are shown second. 3Levels of service are for the opposed northbound left-turning movement at IL RTE. 47/I-88 WB and for the minor-leg approach at IL RTE. 47/I-88 EB.

EXISTING FACILITY (YEAR 2008)

Location Type of Analysis LOS (AM) LOS (PM)

Westbound I-88 (east of IL Freeway A B Westbound I-88 (west of IL Freeway A B Eastbound I-88 (west of IL RTE. Freeway A A Eastbound I-88 (east of IL RTE. Freeway A A Westbound I-88 entrance Merge A B Eastbound I-88 exit Diverge B B IL RTE. 47/Seavey Road2 Intersection A/B A/B IL RTE. 47/I-88 WB ramps3 Intersection A A IL RTE. 47/I-88 EB ramps3 Intersection B B IL RTE. 47/Finley Road2 Intersection A/C A/B IL RTE. 47/Scott Road2 Intersection A/C A/B IL RTE. 47/Merrill Road2 Intersection A/C A/B


14

Based on these capacity results, existing traffic operation is shown to be satisfactory throughout the study network. With minor-leg stop control in place at all study intersections today, traffic on IL Rte. 47 operates with little to no delay. Low-volume traffic on the minor legs is also shown to operate acceptably with LOS C or better at all study intersections. 3.2 Roadway I-88 Reagan Memorial Tollway I-88 is classified as a freeway/tollway and presently has two 12.5-foot mainline lanes in each direction separated by an open grassed median. The posted speed limit is 65 mph. The existing pavement consists of 3.75 inches bituminous concrete on 14 inches of Portland Cement Concrete pavement constructed over 4 inches of stabilized sub-base. The existing shoulders consist of 3 inches of bituminous concrete on a concrete shoulder. The existing half diamond interchange provides access at IL Rte. 47 to and from the west. IL Rte. 47 is carried over the Reagan Memorial Tollway. Toll collection is not provided on either existing ramp. Peace Road is a full service interchange located approximately 15.5 miles west of IL Rte. 47. IL Rte. 56 is a system interchange with ramps to and from the east only and is located approximately 4 miles east of IL Rte. 47. Orchard Road is a full service interchange located approximately 5 miles east of IL Rte. 47. IL Rte. 47 IL Rte. 47 is a designated Strategic Regional Arterial (SRA) Route. IL Rte. 47 is a two-lane undivided roadway north and south of the existing half diamond interchange. At the interchange IL Rte. 47 widens to a five-lane section. IL Rte. 47 is a primary north-south thoroughfare serving the Village of Sugar Grove, Village of Elburn and Kane County. The existing tangent sections approaching the IL Rte. 47 bridge on the north and south side have recently been overlaid with asphalt. Approximately 1,750 feet north of the Tollway centerline is an unsignalized intersection with Seavey Road, an east-west undivided roadway. Approximately 815 feet south of the Tollway centerline, Finley Road is an east-west two-lane undivided roadway that forms a T-intersection with IL Rte. 47. Approximately 3,280 feet south of the Tollway centerline, Scott Road, an east-west two-lane undivided roadway that forms a T-intersection with IL Rte. 47. Aerial photography of the interchange is show in Exhibit 5. 3.3 Lighting Presently, no lighting is provided on the IL Rte. 47 overpass at I-88. Presently, no lighting is provided on the I-88 Tollway mainline.

Ramp lighting is present on the EB off-ramp and WB on-ramp. 3.4 Structural The existing IL Rte. 47 Bridge carries IL Rte. 47 over I-88. The bridge provides for two through lanes in each direction separated by a 20-foot raised median. The deck is 93 feet 2 inches out-to-out. It is a four span bridge with a concrete deck supported by twelve precast, prestressed


15

concrete I-Beams. The overall length between the centerline of abutment bearings is 239 feet 0-inches. Both approach slabs to the bridge section consists of a 15” of concrete with a 4” aggregate base. The bridge superstructure was fully reconstructed in 2007. 3.5 Existing Utilities Resources used for identifying the existing utilities for this project were Illinois Tollway record drawings, Tollway utility and permit files, and utilities identified in the JULIE utility locate system. Notices were sent to all utility owners identified in these sources, and responses have been received from all owners. The following are existing utilities that fall partially or entirely within the proposed footprint of the IL Rte. 47 at I-88 Interchange. Aerial photography and topography of the existing interchange is show in Exhibit 5.

A 6” gas main parallels IL Rte. 47 on the east side through the limits of the project. The line crosses under I-88 approximately 175’ east of IL Rte. 47. The owner has been identified as Nicor. Information on this utility comes from Nicor utility atlases.

North of I-88 overhead electric cables parallel IL Rte. 47 approximately 2’ inside of the west right-of-way line. These overhead cables cross I-88 approximately 125’ west of the IL Rte. 47 centerline. The overhead cables then cross to the east side of IL Rte. 47 at Finley Road and continue south through the limits of the project. The owner has been identified as ComEd. Information on this utility comes from topographic information and drawings supplied by ComEd.

An underground fiber optic cable parallels I-88 within 10 feet south of the north right-of-way line throughout the project limits. The 8” HDPE pipe crosses IL Rte. 47 near the north abutment. The owner has been identified as Adesta. Information on this utility comes from drawings supplied by Adesta.

An underground fiber optic cable runs adjacent to the Adesta line north of I-88 and crosses I-88 approximately 174’ east of IL Rte. 47.

Six 2” HDPE at variable depth runs along the east side of IL Rte. 47 in the right-of-way through the project limits. The owner has been identified as AT&T long distance. Information on this utility comes from drawings supplied by AT&T long distance.

An underground fiber optic cable crosses I-88 approximately 100’ east of IL Rte. 47. The owner is identified as Mediacom. Information on this utility comes from Adesta record drawings.

The following utility companies were identified by the JULIE utility locates, but are clear from any possible construction activities.

Exelon Enbridge Energy Partners

3.6 Land Use Current land use in the immediate vicinity of the I-88/IL Rte. 47 intersection is a mix of farmed land, residential, and privately owned open land. The project area is entirely within Kane County and in Blackberry Township. South of the interchange is the Village of Sugar Grove and north of the interchange is the Village of Elburn.

Northeast Quadrant

The northeast quadrant of the project lies entirely within Blackberry Township. This quadrant of the interchange is owned by Crown Community Development from the I-88 right-of-way to Seavey Road. The parcel is currently farmed along IL Rte. 47. Adjacent to I-88, the Tollway maintains a storage yard in their right-of-way. The environmental report has identified areas of wetland in the ditches adjacent to the I-88 mainline (see Figure 5 and Table 1 of Appendix A).


16

Southeast Quadrant

The southeast quadrant of the project lies entirely within Blackberry Township. This quadrant of the interchange is owned by Crown Community Development from I-88 south to Merrill Road. The parcel is currently undeveloped adjacent to the I-88 right-of-way and farmed south of Blackberry Creek. The environmental report has identified wetlands in the ditch along IL Rte. 47 and in the ditch running east-west approximately 500 feet south of the Tollway centerline. Southwest Quadrant The southwest quadrant of the project lies entirely within Blackberry Township. The area between the existing eastbound off-ramp and Finley Road is currently undeveloped and is owned by a single investor/developer who supports the project. South of Finley Road is a residential development adjacent to IL Rte. 47. The environmental report has identified wetlands in the area between the ramp and Finley Road and in the ditches along the frontage road. Northwest Quadrant The northwest quadrant of the project lies entirely within Blackberry Township. This quadrant of the interchange is owned by Crown Community Development from the I-88 right-of-way to Seavey Road. The parcel is currently farmed along IL Rte. 47. The Tollway maintains a salt storage yard between I-88 and the existing westbound on-ramp in this quadrant. The environmental report has identified wetlands in the ditches along I-88 and a small amount of wetlands in the ditches along IL Rte. 47. 3.7 Existing Right-of-Way Reagan Memorial Tollway (I-88) The general limits of the existing right-of-way for I-88 within the project are approximately 125 feet both north and south of the existing Tollway centerline. However, a wider right-of-way occurs both east and west of IL Rte. 47 for the existing ramps to and from the west and for future ramps to and from the east. IL Rte. 47 The general limits of the existing right-of-way for IL Rte. 47 within the project area are as follows: North of I-88 the right-of-way width is approximately 200 feet wide from the I-88 on-ramp to Seavey Road. South of I-88 the right-of-way width is approximately 130 feet wide south of Finley Road. 3.8 Environmental Conditions An environmental analysis was prepared to assess potential environmental constraints related to the proposed full access interchange at IL Rte. 47 and I-88. This screening is important to the process of identifying feasible configurations for the IL Rte. 47 access. The environmental analysis, which evaluated natural resources including wetlands, water quality, floodplains, and threatened and endangered species, does not indicate any adverse environmental impacts. The analysis also includes an investigation of potential hazardous material within the study area. Appendix A contains the full Environmental Analysis for the Interchange Study.


17

4.0 INTERCHANGE LAYOUTS The six configurations considered for the IL Rte. 47 and I-88 interchange include:

Option 1 - Conventional Diamond Interchange Option 2 - Northeast Loop Ramp Option 3 - Eastbound I-88 Loop Off-Ramp Option 4 - Diverging Diamond Interchange Option 5 - Single Point Urban Interchange (SPUI) Option 6 - No Build Alternative

The selection of the type of service interchange is dependent on the following:

Safety and Capacity Turning traffic volume at the ramp intersections Right-of-Way availability and cost Effect on the adjacent environmental resources Funding

Each of the interchange designs comply with the latest Illinois Tollway geometric design criteria, with the exception of the Eastbound I-88 Loop Off-Ramp for the ramps and mainline and IDOT’s design standards for IL Rte. 47 and the associated traffic signals. The Illinois Tollway requires a minimum Level of Service (LOS) D capacity be provided at the following elements of the interchange:

Tollway mainline Entrance and Exit Ramp junctions Signalized or Unsignalized Ramp intersection with cross street.

Designs were evaluated based on traffic volumes generated and documented in the Interchange Volumes Study developed by Metro Transportation and included in Appendix E of this report. The projections made in Metro’s study have been previously reviewed and commented on by the various jurisdictional agencies including IDOT, Illinois Tollway, and KDOT. Per direction given by these agencies, the Interchange Volume Study has been updated to incorporate agency comments; dispositions responding to these comments are included in Appendix G. 2020 and 2030 volumes include local and regional growth and the developments proposed within the study area. Volumes from the Crown Development were obtained from the developer’s engineer and include the planned residential, commercial, industrial and retail land uses. Other development information was obtained through working with the Villages of Sugar Grove and Elburn. Proposed Village land use plans in the vicinity of the interchange are included in the volume study. The volume study also considers traffic that will reroute from IL Rte. 47 to the proposed Prairie Parkway to perform regional trips by design year 2030; it was assumed that these vehicles would travel between Prairie Parkway and IL Rte. 47 via I-88, thereby adding to the eastbound to northbound and southbound to westbound movements at the subject interchange. The predominant turning movements on the project are the southbound IL Rte. 47 to eastbound I-88 movement and the westbound I-88 to northbound IL Rte. 47 movement. The IL Rte. 47 Interchange with IL Rte. 56 is located on the south side of Sugar Grove. This interchange reduces anticipated volumes for the northbound IL Rte. 47 to eastbound I-88 movement and the westbound I-88 to southbound IL Rte. 47 movement. Interchange ramp and intersection designs accommodate the 2030 traffic projections developed in the volume study.


18

Design year traffic projections for the study area reveal fairly balanced utilization on each of the interchange ramps. With a strong commercial presence predicted for the study area, traffic generated by retail, office, and industrial uses balances the commuter travel patterns of residential motorists. On the west ramps, background traffic volumes contribute to design year projections that are similar in magnitude to those on the east ramps. These travel patterns are atypical for an interchange located in an outer suburban community of the Chicago region, but are not surprising given the small number of area interchanges providing access to and from the west. It should be noted that the IL Rte. 47/Finley Road intersection currently operates as a full-access “T”-intersection. After further discussion with agency staff, however, the project team has assumed that Finley Road will operate as a right-in/right-out access intersection for the purposes of developing geometrics for the study area (where applicable). The project team is in agreement with jurisdictional agencies that Finley Road, which is located within the Illinois Tollway access control limits, should not be maintained with full access for safety reasons. Yet given this roadway’s current utilization by adjacent residents (and the additional two-plus miles that would be traveled by these residents along the shortest alternate route to IL Rte. 47), it is the project team’s conclusion that a ¾ access at IL Rte. 47/Finley provides adequate accessibility without compromising vehicular safety. The ability to provide three-quarters access at Finley Road while providing safe and efficient operation for area motorists is further discussed in Section 5.3.2. 4.1 Option 1 - Conventional Diamond Interchange Traffic As proposed, the conventional diamond interchange would use the existing I-88 structure and include a four-lane section on IL Rte. 47. It should be noted that the Conventional Diamond has been designed such that it would not preclude the construction of a northeast loop ramp (Option 2) in the future, if needed. (See Exhibit 1 for an overview.) Cost

Lowest cost alternative of the build alternatives. The existing IL Rte. 47 overpass can remain with this interchange configuration.

See Appendix I for a detailed breakdown of the construction costs for all alternatives.

PROPOSED FACILITY (CONVENTIONAL DIAMOND INTERCHANGE)

Improvement Type Cost (millions)

Ramps and Toll Plazas $6.56IL Rte. 47 Improvements $4.02Seavey Road $0.08Finley Road $0.10Maintenance of Traffic $0.33Excavation $1.10Signing $0.16Mobilization $0.37Contingency (25%) $3.18Engineering Costs $2.38Utility Relocations $0.33Right-of-Way Acquisition $1.08TOTAL $19.7 Million


19

Right-of-Way The approximate limits of the right-of-way impacts identified based on the proposed conventional diamond interchange horizontal geometry are as follows:

NE Quadrant: Construction of the conventional diamond interchange will require approximately 0.7 acres from Parcel 4, which is owned by Crown Community Development. 0.1 acres of right-of-way will also be acquired from Parcel 4 along IL Rte. 47 for the improvements approaching Seavey Road.

NW Quadrant: The proposed ramp improvements in the NW quadrant of the interchange will fit in the existing I-88 right-of-way. Approximately 0.2 acres of right-of-way will be acquired from Parcel 3 for the improvements at Seavey Road. Crown Community Development owns Parcel 3.

SE Quadrant: The proposed ramp improvements in the SE quadrant of the interchange will fit in the existing I-88 right-of-way. Approximately 0.2 acres of right-of-way will be acquired from Parcel 8 for the improvement on IL Rte. 47 approaching Blackberry Creek. Crown Community Development owns Parcel 8.

SW Quadrant: Widening for the proposed ramp improvement in the SW quadrant of the

interchange will require approximately 0.3 acres of right-of-way from Parcel 5, which is owned by an investor/developer who supports the project. Widening for the IL Rte. 47 improvements will be done to the east side of the roadway in order to minimize impacts to the residential parcels along the west side of the roadway.

An exhibit showing the right-of-way associated with the conventional diamond interchange is shown in Exhibit 16. Additionally there is an exhibit showing the additional right-of-way needed for a NE Loop Ramp which is attached to the report as Exhibit 7. Structural Evaluation One of the primary benefits of the conventional diamond interchange configuration is that the existing IL Rte. 47 overpass can accommodate 2030 traffic. The superstructure of this bridge was fully reconstructed in 2007. The only improvements proposed across the structure are modifications to the existing median to extend the length of the southbound left turn lane to the I-88 eastbound on-ramp. Environmental Impacts The approximate environmental impacts that have been identified based on the proposed conventional diamond interchange horizontal geometry are as follows (Wetlands are described in further detail in Appendix A):

NE Quadrant: Impacts to the wetland in the ditch on the north side of I-88 for the construction of the proposed WB off-ramp to IL Rte. 47. This wetland is identified as Site 4 in the Environmental Analysis. Additional r/w is necessary if future NE Loop Ramp is considered.

NW Quadrant: Impacts to the wetland in the ditch on the north side of I-88 for the construction of the proposed WB on-ramp improvements. These wetlands are identified as Site 6 and Site 7 in the Environmental Analysis. The NW quadrant of the interchange also contains a leaking underground storage tank (LUST) site at 11 Salt Dome Way. The incident involved diesel fuel. A No Further Remediation Letter (NFR) was issued on May 8, 1997.

SE Quadrant: Impacts to the wetland in the ditch on the east side of IL Rte. 47 (Wetland Site 10) for the construction of the proposed EB on-ramp to I-88.


20

SW Quadrant: Impacts to the wetlands in the ditch on the south side of the existing WB

I-88 off-ramp (Wetlands Site 11 and Site 12) for the construction of the proposed ramp improvements.

This configuration is not anticipated to cause impacts to Kane County Mapped ADID Wetlands. As indicated in the Environmental Analysis, the portion of the study area along IL Rte. 47 between Finley Road and the southern project boundary has not been evaluated for environmental issues including wetland impacts. This area will be evaluated in a subsequent phase of the project. No wetlands were identified within this area on the National Wetland Inventory (NWI) map, the Kane County ADID Wetland map, or the Natural Resources Conservation Service (NRCS) map. Wetland delineation will occur in a subsequent phase of the project in order to confirm the presence/absence of wetlands in this area. Utility Impacts The 6” Nicor gas main on the east side of IL Rte. 47 south of I-88 will be impacted by the IL Rte. 47 widening and intersection improvements. These Nicor impacts are reflected in the estimate as a $150,000 cost for the proposed relocations. Adesta fiber optic lines will likely require relocation for the proposed EB off-ramp construction between Sta. 5796+40 and 5799+60 on the north side of I-88. These Adesta impacts are reflected in the estimate as a $5,000 cost for the proposed relocations. AT&T underground utilities on the east side of IL Rte. 47 south of I-88 will be impacted by the IL Rte. 47 widening and intersection improvements. These AT&T impacts are reflected in the estimate as a $30,000 cost for the proposed relocations. Approximately 16 Com Ed utility poles carrying overhead electric and communication lines will be impacted by the ramp improvements and IL Rte. 47 widening. Impacts to these overhead lines are reflected in the estimate as $2,500 per utility pole requiring relocation as part of the project. 4.2 Option 2 – Northeast Loop Ramp An overview of the Northeast Loop Ramp is attached to the report as Exhibit 2. Traffic The addition of a Northeast Loop Ramp was recommended for further study, based on the June 5, 2009 meeting with IDOT and the Illinois Tollway. The intent of this design was to remove the back-to-back left-turn lanes across the bridge. Back-to-back left-turn lanes have caused operational issues at some diamond interchanges in the area. It was therefore suggested by agency staff that avoiding this type of configuration would be beneficial to the overall traffic scheme. Capacity analysis of this interchange configuration revealed that the addition of the northeast loop ramp did not have a significant increase in capacity over the standard conventional diamond interchange configuration. Because the most critical movements at the interchange are the southbound left turns and northbound through vehicles at the EB I-88 ramp intersection, the addition of a northeast loop ramp at I-88 W is not expected to provide a great benefit to overall interchange operation. Cost

Increased cost from the conventional diamond due to the increase in right-of-way allocation and associated costs for additional new ramp.

The bridge will need modifications to account for the new ramp.


21

Complete relocation of Tollway Storage area.

Right-of-Way (see Exhibit 7)

NE Quadrant – Impacts 1 parcel owned by Crown Community Development. The NE quadrant is especially impacted as the addition of northeast loop ramp extends the right-of-way required.

NW Quadrant – Impacts 1 parcel owned by Crown Community Development. SW Quadrant – Impacts 1 parcel owned by a private developer. SE Quadrant – Impacts 1 parcel owned by Crown Community Development.

Environmental Impacts

NE Quadrant – Impacts Wetland Site 4 and 5. NW Quadrant – Impacts Wetland Sites 6 and 7. SW Quadrant – Impacts Wetland Sites 11 and 12. SE Quadrant – Impacts Wetland Site 10.

The additional costs associated with the ramp improvements, right-of-way, and structural impacts need to be justified for the proposed improvements. Further evaluation of this possible alternative will be undertaken in the subsequent phase of design. 4.3 Option 3 – Eastbound I-88 Loop Off-Ramp A southeast loop ramp configuration was investigated as part of the Interchange Feasibility Study. This configuration removes the existing EB I-88 Off-Ramp and replaces it with a loop ramp in the southeast quadrant of the interchange. Both the Tollway and IDOT recommended that this design alternate not be pursued beyond the concept stage and therefore it is not considered a feasible option in the Interchange Feasibility Study. The objections raised included substandard geometry in the southeast quadrant and the issue of terminating the SE ramp across from a local street.

PROPOSED FACILITY (NE LOOP RAMP INTERCHANGE)




22

4.4 Option 4 – Single Point Urban Interchange (SPUI) An overview of the Single Point Urban Interchange is attached to the report as Exhibit 3. Traffic A SPUI is a variation of a diamond interchange that has a very tight spacing between the interchange ramps. This close spacing allows the ramps to operate as a single signalized intersection. SPUIs work best when turning movements are balanced at the interchange, which is the case on the ramps and on IL Rte. 47. Benefits of the SPUI interchange configuration include that it could be constructed in the existing right-of-way of the current interchange and the ramp locations would provide more room to place driveways on IL Rte. 47 outside of access control limits. Cost

Significant increase in cost due to the complete reconstruction of IL Rte. 47 overpass Most expensive of all alternative interchange designs

Right-of-Way This alternative has the smallest footprint and therefore the least amount of right-of-way required for construction. The proposed schematic, Exhibit 8, for this alternative shows no additional right-of-way required. Environmental Impacts


A SPUI is considered a feasible option for the proposed interchange due to its increased safety and traffic capacity. However, since this option does not allow for the existing overpass to remain,

PROPOSED FACILITY (SINGLE POINT URBAN INTERCHANGE)




23

it becomes the most costly option under consideration. All the factors associated with the SPUI option will be further investigated in the next phase of design. 4.5 Option 5 – Diverging Diamond Interchange An overview of the Diverging Diamond Interchange is attached to the report as Exhibit 4. Traffic This interchange option would have the opposing lanes of IL Rte. 47 criss-cross at traffic signals on the north and south side of I-88. This interchange option eliminates the need for left-turning vehicles to turn across the opposing travel lanes and allows for two-phased signal timings. Diverging diamonds work best when there are significant turning movements to and from the intersecting roadway. At this interchange, traffic is high on northbound and southbound IL Rte. 47 but the turning movements to and from the I-88 ramps are light as compared to other typical suburban interchanges. The long distance between the signalized crossover intersections, a product of the existing bridge length, could also increase delays on IL Rte. 47. In order to maintain progression along IL Rte. 47 without stopping vehicles at both ramp intersections, a longer cycle length would likely be required for the study area’s interconnected signal system. As a result, the minor legs and turning vehicles would be expected to operate with more delay and longer queues than would be expected for the other feasible design alternatives. Vehicular delay would presumably be less with a DDI configuration if the ramp intersections were more closely spaced, but the recent bridge reconstruction and the costs associated with complete reconstruction of existing ramps make this undertaking undesirable. In addition, the presence of both horizontal and vertical curvature along the IL Rte. 47 alignment near the interchange adds additional complication to the reverse curves that are needed to provide the geometrics associated with the crossover intersections. Closely spaced existing (and potential future) intersections and access points also reduce the potential benefits of the DDI configuration. Cost

The cost of this option is only slightly higher than the lowest cost option (conventional diamond interchange).

Minor median improvements across bridge.

PROPOSED FACILITY (DIVERGING DIAMOND INTERCHANGE)




24

Right-of-Way This alternative takes limited right-of-way but impacts the Tollway storage yard. Exhibit 9 illustrates the overall right-of-way impact associated with this alternative. Environmental Impacts


The Diverging Diamond Interchange (DDI) was recommended for further study based on the June 5, 2009 meeting with IDOT and the Tollway. The DDI was a desirable option due to its potential for greater capacity than a conventional diamond, and the likelihood that minimal right-of-way would be necessary. 4.6 Option 6 – No-Build Alternative An overview of the current interchange is attached to the report as Exhibit 5. This exhibit shows the existing 4-lane mainline section under the existing IL Rte. 47 overpass. Since this option does not meet the previously discussed need for additional access to and from the east, further analyses (cost, right-of-way, and environmental) were not performed for this option. 4.7 Feasibility Discussion A summary of the evaluation criteria used to evaluate each alternative for the I-88/IL Rte. 47 interchange is included in Table 4-1 “Alternative Evaluation Matrix”. After a review of the Alternative Evaluation Matrix for the 6 interchange layout alternatives discussed above, only the full service conventional diamond interchange met the purpose of the project for the 2030 design and warrants further discussion. The primary criterion on which this interchange should be evaluated is how it accommodates 2030 traffic volumes. 4.8 Ultimate Interchange Alternates The 2030 design is in the scope of the Feasibility Study and is the previously agreed upon timeframe for the scope of the Feasibility Study as agreed to with the Tollway and IDOT. After agency approval of the Feasibility Study for the interchange, the next step for the project will be the Phase I Study. The Ultimate configuration will be addressed during Phase I in consideration of CMAP’s most up-to-date numbers. Feasible alternatives for the ultimate design include:

Conventional diamond – Potentially with side-by-side dual left-turn lanes. Single Point Urban Interchange (SPUI) Diverging Diamond Interchange (DDI) Northeast Loop Ramp

All four alternates can accommodate traffic projections through design year 2030. Widening of IL Rte. 47 would be required to accommodate a 6 lane section on IL Rte. 47. The ultimate IL Rte. 47 design for the conventional diamond interchange may require a 10-lane section over I-88 comprised of three through lanes in each direction on IL Rte. 47 side-by-side dual left-turn lanes for both movements onto I-88. Based on available mapping, the right-of-way shown in this Feasibility Study accommodates the design through 2030. More specific right-of-way information will be available after topographic surveying is completed in Phase I.


25

The SPUI configuration will accommodate ultimate traffic projections at the interchange. This design fits within the existing right-of-way at the interchange and the tight ramp configuration will reduce the distance access control is required from the centerline of I-88. The DDI configuration is an efficient design which provides the capacity necessary for anticipated traffic projections. It reduces multiple conflict points, but could lead to driver confusion since it is a new type of interchange which requires motorists to travel on the left-side of the roadway through the interchange. The last alternative, a northeast loop ramp design, would address the back-to-back left condition that can become an issue with conventional diamonds. The introduction of a northeast loop ramp would negate the need for a left turn storage and taper for vehicles travelling northbound to westbound. Instead, this area could be used for the storage and taper for vehicles travelling southbound to eastbound. 4.9 AET (All Electronic Tolling) vs. Cash Tolling AET is presently shown on all interchange ramp alternatives. However, approximately 20% of Tollway patrons are cash customers, who pay double the rate of I-Pass users. If patrons paying cash cannot utilize this interchange, it can be assumed that the Tollway will lose revenue. Conversely, there is a construction cost associated with making these changes to any proposed alternative. Additional electronic, structural, and geometric design considerations need to be taken into account to make this a viable option, and these variables will increase the cost of the overall project. A geometric comparison of the AET vs. Cash is shown in Exhibit 14.

26

Table 4-1: Alternative Evaluation Matrix

PROPOSED FACILITY (YEAR 2030)

Evaluation Criteria Comments Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5 Alternative 6

Alternate Description

Conventional Diamond NE Loop Ramp

Eastbound I-88 Loop Off-Ramp

Single Point Urban Interchange (SPUI)

Diverging Diamond Interchange No-Build

Geometry and Compatibility with Regional Planning

Regional connectivity and local

development plans

Full service interchange enhances regional

connectivity and meets local municipalities

planning requirements.













No ramps to and from the east results in additional

traffic on the local roadway network and at adjacent interchanges. Does not meet local municipalities’ planning requirements.

Future Traffic Operations (2030)

Operational characteristics on IL Rte. 47 and at ramp

intersections for 2030 traffic projections

Ramp intersections operate at LOS B or C during both

peak hours. All study intersections meet IDOT and ISTHA’s operational

standards.

Elimination of northbound left turn at WB I-88 ramp provides a minor capacity benefit at this intersection

over Conventional Diamond.

Four-legged intersection configuration at EB I-88

ramps results in increased intersection delay over that

of a Conventional Diamond.

Efficient single-point design provides adequate capacity

for all movements and alleviates storage problems

from closely spaced crossroad intersections.

Configuration puts through movements at ramp

intersections in conflict and requires higher cycle length

for progression along IL Rte. 47. As a Result

overall Delay is higher throughout the study area.

No-build scenario results in less traffic at ramp

intersections and therefore less delay; congestion on regional roadway network likely to increase without

access to I-88 to/from east.

New Right-of-Way Required

New right-of-way required to construct

the alternative.

Approximately 4.3 Acres No relocations required





No right-of-way required

Safety Standard configuration meets drivers’ expectation

and provides a safe interchange configuration.

Loop Ramp reduces conflict points as compared

to the Conventional Diamond by eliminating the northbound left turn at the WB I-88 ramp intersection.

Configuration of EB off ramp does not meet

AASHTO requirements. Local road at freeway ramp intersection does not meet

FHWA standards.

Single intersection for all freeway ramps & IL Rte. 47 reduces conflict points at

the interchange.

Left turn conflict points completely eliminated with

design. Non standard design could potentially lead to driver confusion.

Without addition of ramps to/from east, number of

conflict points remains the same as today. Traffic signals would likely be

added when warranted, in accordance with IDOT

SRA Report.

Existing Infrastructure Impacts

Structural and Tollway storage yard

impacts.

Minor median improvements across

bridge. Minor impacts to Tollway

storage yard

Retaining walls and beam replacement required to fit ramp through the currently

enclosed north span. Complete relocation of storage yard required.


bridge. Minor impacts to Tollway

storage yard

Retaining walls and full replacement of existing

bridge required. Major impacts to the Tollway storage yard.


bridge. Major impacts to Tollway

storage yard

None

27

Table 4-1: Alternative Evaluation Matrix (Continued)


Evaluation Criteria Comments Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5 Alternative 6

Alternate Description

Conventional Diamond NE Loop Ramp

Eastbound I-88 Loop Off-Ramp

Single Point Urban Interchange (SPUI)

Diverging Diamond Interchange No-Build

Planning-Level Construction Cost Estimate

Includes construction cost, contingency,

right-of way, utilities and engineering

$19.7 Million $24.3 Million $21.3 Million $32.4 Million $20.5 Million $0 Million

Operational Cost Long term maintenance and

energy consumption

Moderate Requires toll plaza

maintenance, electricity & signal maintenance.

Moderate Similar to Alternate 1


High Large bridge and retaining

walls will result in significantly higher

maintenance cost over the other build options.


.

Moderate Increased energy

consumption as traffic must travel significant distances

from their origins and destination to reach EB

I-88.

Construction Impact Temporary impacts from traffic delays

Low Existing overpass to

remain which minimizes impacts to I-88 and

construction duration on IL Rte. 47

Moderate Existing overpass to

remain which minimizes impacts to I-88 and

construction duration on IL Rte. 47

Moderate Partial reconstruction of north span and retaining

wall construction will increase project duration

and impact traffic on I-88 & IL Rte. 47

High Complete reconstruction of IL Rte. 47 overpass which will impact traffic on I-88 &

IL Rte. 47. Longest construction duration of

alternates.

Moderate Existing overpass to

remain which minimizes impacts to I-88. Full

closures likely required on IL Rte. 47 for construction

of crossovers

None

Environmental Impact

Impacts on natural resources

Low Low Low Low Low None


28

5.0 TRAFFIC EVALUATION OF INTERCHANGE DESIGN ALTERNATIVES 5.1 Projected Traffic Volumes In order to evaluate the potential for both an interim and ultimate interchange improvement, the project team developed projected traffic volumes for both 2020 and 2030 design years. These traffic volumes, as well as the methodology used to calculate them, can be found in the Interchange Volumes Study in Appendix E. Yet after performing capacity analyses for the two design years (detailed in Section 5.2), it was determined that the improved I-88/IL Rte. 47 interchange geometry would provide adequate capacity for the projected 2020 and 2030 traffic volumes. As such, the following section provides only 2030 capacity analysis for most of the potential interchange design alternatives. In order to affirm the ability of the proposed geometry to accommodate 2020 and 2030 traffic volumes, capacity results are provided for both design years with a Conventional Diamond Interchange design. The remaining feasible designs – a Northeast Loop Ramp, a Diverging Diamond Interchange (DDI), and a Single-Point Urban Interchange (SPUI) – were only evaluated for 2030, with the assumption that 2020 traffic volumes could be accommodated as well as or better than 2030 volumes. 5.2 Traffic Analysis of the System Operation along mainline I-88 was evaluated with the use of HCS+ capacity analysis software for design years 2020 and 2030. It is important to note that the analyses performed for the interchange ramp merging and diverging areas are based on measurements obtained from the Conventional Diamond Interchange design, which is currently expected to the most feasible alternative. It is anticipated that the merge/diverge areas would have a similar layout for the remaining design alternatives and would therefore operate similarly to the operational projections shown in Table 5-1.


29

Table 5-1 – 2020 & 2030 HCS Capacity Analysis I-88 Mainline

Per direction from agency staff, intersection operation was evaluated for each design alternative with the use of Synchro 7 capacity analysis software. As noted previously, the Conventional Diamond Interchange was evaluated for 2020 and 2030 in order to demonstrate that the proposed intersection geometrics can accommodate traffic projections for both design years. Capacity results for this design are presented in Table 5-2. Capacity results for the remaining design alternatives (in 2030 only) are presented in Tables 5-3 through 5-5.

Location Type of Analysis LOS (AM) LOS (PM)

DESIGN YEAR 2020Westbound I-88 (east of IL Freeway B C Westbound I-88 @ IL RTE. 47 Freeway A B Westbound I-88 (west of IL Freeway B B Eastbound I-88 (west of IL RTE. Freeway B B Eastbound I-88 @ IL RTE. 47 Freeway B B Eastbound I-88 (east of IL RTE. Freeway B B Westbound I-88 exit Diverge B C Westbound I-88 entrance Merge B B Eastbound I-88 exit Diverge B B Eastbound I-88 entrance Merge B B

DESIGN YEAR 2030Westbound I-88 @ IL RTE. 47 Freeway B C Westbound I-88 (west of IL Freeway B C Eastbound I-88 (west of IL RTE. Freeway C C Eastbound I-88 @ IL RTE. 47 Freeway B B Eastbound I-88 (east of IL RTE. Freeway C C Westbound I-88 exit Diverge B C Westbound I-88 entrance Merge B C Eastbound I-88 exit Diverge C C Eastbound I-88 entrance Merge B C


30

Table 5-2 – 2020 & 2030 Synchro Capacity Analysis Conventional Diamond Interchange

1For the purpose of analysis, it was assumed that IL RTE. 47/Finley will operate as a right-in/right-out intersection with this interchange design; reported levels of service are for the minor-leg right-turning movement. 2In 2030, the southbound left-turning movement at IL RTE. 47/Merrill is expected to operate at LOS A during the morning peak and at LOS B in the evening. The minor-leg approach is shown to operate at LOS C during both peak hours. 3In 2030, the southbound left-turning movement at IL RTE. 47/Merrill is expected to operate at LOS B during both peak periods, while the minor-leg approach is shown to operate at LOS D during both peak hours.

Table 5-3 – 2030 Synchro Capacity Analysis Northeast Loop Ramp Design

1For the purpose of analysis, it was assumed that IL RTE. 47/Finley will operate as a right-in/right-out intersection with this interchange design; reported levels of service are for the minor-leg right-turning movement. 2The southbound left-turning movement at IL RTE. 47/Merrill is expected to operate at LOS B during both peak periods, while the minor-leg approach is shown to operate at LOS D during both peak hours.

Location Type of Analysis

Level of Service

AM PM

DESIGN YEAR 2020IL RTE. 47/Seavey Road Intersection C C IL RTE. 47/I-88 WB ramps Intersection A B IL RTE. 47/I-88 EB ramps Intersection A A IL RTE. 47/Finley Road1 Intersection B B IL RTE. 47/Scott Road/Denny Intersection B B IL RTE. 47/Merrill Road2 Intersection A/C B/C

DESIGN YEAR 2030IL RTE. 47/Seavey Road Intersection C D

IL RTE. 47/I-88 WB ramps Intersection B C

IL RTE. 47/I-88 EB ramps Intersection B B

IL RTE. 47/Finley Road1 Intersection B B

IL RTE. 47/Scott Road/Denny Intersection B C

IL RTE. 47/Merrill Road3 Intersection B/D B/D


Level of Service

AM PM

IL RTE. 47/Seavey Road Intersection C D IL RTE. 47/I-88 WB ramps Intersection B B IL RTE. 47/I-88 EB ramps Intersection B B IL RTE. 47/Finley Road1 Intersection B B IL RTE. 47/Scott Road/Denny Intersection B C IL RTE. 47/Merrill Road2 Intersection B/D B/D


31

Table 5-4 – 2030 Synchro Capacity Analysis Diverging Diamond Interchange

1The reported levels of service for both ramp intersections refer to the location at which mainline IL RTE. 47 volumes meet at the DDI “crossover” intersections. 2It is assumed that Finley Road would become a cul de sac just west of IL RTE. 47 if a DDI interchange design were implemented. 2The southbound left-turning movement at IL RTE. 47/Merrill is expected to operate at LOS B during both peak periods, while the minor-leg approach is shown to operate at LOS D during both peak hours.

Table 5-5 – 2030 Synchro Capacity Analysis Single-Point Urban Interchange

1For the purpose of analysis, it was assumed that IL RTE. 47/Finley will operate as a right-in/right-out intersection with this interchange design; reported levels of service are for the minor-leg right-turning movement. 2The southbound left-turning movement at IL RTE. 47/Merrill is expected to operate at LOS B during both peak periods, while the minor-leg approach is shown to operate at LOS D during both peak hours.

Based on the capacity analyses performed, it is anticipated that acceptable operation could be achieved at each of the study intersections and along mainline I-88 with any of the considered design alternatives. Though some of the designs provide better operation than others for certain movements, most of the study intersections are expected to operate within agency standards during both peak hours with few variance requests for movements exceeding LOS D (or LOS C for through movements on IL Rte. 47). The only design that is expected to provide a significantly different standard of operation is the Diverging Diamond Interchange. Because of the spacing of the existing ramps, signal timings were designed with a longer cycle length to maximize progression on IL Rte. 47 through the crossover intersections. As a result, some intersections (and especially the minor-leg approaches) operate with more delay than with the other designs. The longer cycle length also results in longer wait times for turning movements and, therefore, longer queue lengths. It is possible that an alternate timing plan with a shorter cycle length could be used for the DDI design, therefore requiring more stops along mainline IL Rte. 47 but allowing


Level of Service

AM PM

IL RTE. 47/Seavey Road Intersection C D IL RTE. 47/I-88 WB ramps1 Intersection C C IL RTE. 47/I-88 EB ramps1 Intersection B C IL RTE. 47/Finley Road2 Intersection N/A N/A IL RTE. 47/Scott Road/Denny Intersection B B IL RTE. 47/Merrill Road3 Intersection B/D B/D



Level of Service

AM PM

IL RTE. 47/Seavey Road Intersection C D IL RTE. 47/I-88 ramps Intersection B B IL RTE. 47/Finley Road1 Intersection B A IL RTE. 47/Scott Road/Denny Intersection B C IL RTE. 47/Merrill Road2 Intersection B/D B/D


32

the potential for improved minor-leg operation and shorter queues for turning movements. If the DDI is selected as a preferred design, these varied timing plans would be explored further in later stages of study. 5.3. Access Control Limitations Based on direction provided by agency staff, the project team explored the potential for shorter access control limits along IL Rte. 47 in order to provide potential operational benefits to the major study intersections. To evaluate these potential benefits, two specific access scenarios were evaluated: limited development access to IL Rte. 47 between Seavey Road and the I-88 ramps (specifically, a right-in for northbound traffic and right-out for eastbound traffic) and three-quarters access (right-in/right-out/left-in access) at Finley Road. The findings of these two evaluations are provided subsequently. See Exhibit 6 for Illinois Rte. 47 access control. 5.3.1. North Side Access Driveway Evaluation Based on data provided by Crown Community Development, the project team developed rerouted 2030 traffic projections for IL Rte. 47/Seavey Road and the potential limited access driveways to the State route. For the potential access to development parcels on the northeast interchange quadrant, it was assumed that the right-in driveway would serve an internal roadway that would allow motorists with an attractive means of access to several parcels east of IL Rte. 47. The right-out access serving the northwest interchange quadrant is expected to serve only one parcel planned by Crown Community Development. Traffic that is rerouted to these two access driveways would reduce the number of vehicles at IL Rte. 47/Seavey for the northbound and eastbound right-turning movements. Table 5-7 presents the projected redistribution of traffic to the new access driveways. Table 5-7 – 2030 Traffic Projections at Potential Access Driveways Morning Peak Hour Evening Peak Hour IL RTE. 47/Northbound Right-In Access

95 215

IL RTE. 47/Eastbound Right-Out Access

20 120

Based on the revised 2030 traffic projections at IL Rte. 47/Seavey, analyses reveal that the greatest benefit of the subject access driveways is the queue reduction for the northbound right-turning movement. With the addition of the northbound right-in access, northbound right-turn queues at IL Rte. 47/Seavey are expected to decrease by 45 feet (over 13 percent). The north- and eastbound right-turning movements at IL Rte. 47/Seavey are expected to experience less delay as a result of these access driveways; yet because these two right turns are not critical movements, the benefit to overall intersection operation is limited. Based on discussions with agency staff, it is anticipated that the subject right-in and right-out driveways could be provided without infringing upon the access control limits set by IDOT, but with a reduction in the length of ISTHA access control limits. 5.3.2. Finley Road Three-Quarters Access Evaluation

Given Finley Road’s current status as a full access intersection at IL Rte. 47, it has been an ongoing discussion amongst the project team and agency staff about the future access limitations that may be imposed on the IL Rte. 47/Finley intersection. Given the lack of attractive alternate routes to and from IL Rte. 47 for parcels on the southwest interchange quadrant, the project team evaluated capacity and sight distance for a three-quarters access (right-in/right-out/left-in) at Finley Road. Traffic operation for a three-quarters access at IL Rte. 47/Finley in 2030 is presented in Table 5-8.


33

Table 5-8 –2030 Levels of Service for IL Rte. 47 & Finley Three-Quarters Access Morning Peak Hour Evening Peak Hour IL Rte. 47/Finley Road

Northbound (Left) B C Eastbound (Right) B B

With a three-quarters access in place, all opposed turning movements at IL Rte. 47/Finley Road are shown to operate within agency standards. Assuming a multi-unit truck design vehicle for this intersection, calculations were performed to determine the necessary sight distance for a left turn from the major street to a minor street on IL Rte. 47. Using data provided in the American Association of State Highway and Transportation Officials (AASHTO) Geometric Design of Highways and Streets, 2004, it can be determined that a minimum 785 feet of sight distance is required to safely perform a northbound left-turning movement from IL Rte. 47 to Finley Road. As shown on Exhibit 18, this minimum intersection sight distance is exceeded by the existing and proposed roadway profile. It is therefore the project team’s assertion that a three-quarters access at IL Rte. 47/Finley Road would operate safely and with adequate capacity in design year 2030.


34

6.0 COMPATIBILITY WITH LOCAL AND REGIONAL PLANNING 6.1 Design Standards The freeway configurations presented follow Illinois Tollway and IDOT geometric design criteria. Appendix B and C summarize the Illinois Tollway’s design and geometric criteria for mainline I-88, interchange ramps, proposed structures, and toll plazas. 6.2 Support of Local Jurisdictions and Regional Planning Agencies Support of a full access interchange at IL Rte. 47 and I-88 include the following local jurisdictions and regional planning agencies:

Village of Sugar Grove Village of Elburn Kane County Board CMAP

Appendix H contains supporting information from Local Jurisdictions. 6.3 Compatibility with Local and Regional Planning Village of Sugar Grove Transportation Planning Study – Engineering Enterprises, Inc. - April 2007. The Village of Sugar Grove Transportation Planning Study serves as the principal policy document to guide future community development and act as a basis for resource management decisions of Village officials. The study identifies a full interchange at the I-88/IL Rte. 47 intersection as a key element of the transportation planning study. The Transportation Plan from the Village’s Comprehensive Transportation Plan is included in Attachment J. Kane County 2030 Transportation and Land Resource Management Plans The 2030 Transportation and Land Resource Management Plan includes the construction a 4- lane section on IL Rte. 47 through the limits of the project and a complete interchange at I-88/IL Rte. 47. Kane County Transportation Planning Area Study; Sugar Grove, Aurora, Montgomery Planning Area Transportation Plan - CH2MHILL – April 2004 The Sugar Grove, Aurora, Montgomery Transportation Improvement Plan recommends the construction a 4-lane section on IL Rte. 47 through the limits of the project and a complete interchange at I-88/IL Rte. 47. Strategic Regional Arterial (SRA) IL Rte. 47 – Illinois Department of Transportation – August 1995. The Illinois Route 47 SRA is intended to function as part of a regional arterial system. It, along with other SRA routes and the regional expressway and transit systems, provide a network to carry high volumes of long-distance traffic. The Interchange Feasibility Study boundary falls within Segment 3 (Old Oak Road to Alternative Alignment [Hughes Road]) of the SRA study and it recommends the improvements shown below (bulleted) for this segment of IL Rte. 47. We have added italicized text after the recommendations to indicate if and how these recommendations are addressed as part of the Feasibility Study:


35

Develop four 12 ft. through lanes, a grass median, shoulders and open drainage. The

right-of-way between Scott Road and Finley Road will be expanded to 180 ft. From Old Oak Road to Scott Road; and from Finley Road to Hughes Road, the right-of-way will be expanded to 160 ft.-200 ft. 12 foot lanes will be provided, curb and gutter will be used in the median, and a rural section utilized on the outside. This allows minimal right-of-way take, matches the existing IL Rte. 47 section at the I-88 bridge, and reduces cost due to the open drainage on the outside. A request to re-designate this section of Route 47 to “suburban” will be made in Phase I, as this reflects the nature of development in the area and is consistent with recommendations in the recently completed Illinois Route 47 Corridor Study.

Develop frontage roads on the west side of Illinois Route 47 between Scott Road and

Finley Road. The frontage road would require significant right-of-way on the west side of the roadway, with potential residential displacements. The preferred interchange configuration minimizes right-of-way and is less disruptive to existing residential property.

Provide single left and right turn lanes at the approaches at the Interstate 88

intersections. Turn lanes are to be provided at all approaches to the interchange intersections.

Provide signals at Old Oak Road, Scott Road, the Interstate 88 ramps, Seavey Road,

Green Road, and Main Street. Signals are to be provided at the intersections with the I-88 ramps. The Seavey Road intersection is designed to accommodate the installation of a future signal. The other aforementioned intersections are outside the limits of the interchange improvement.

Manage access with median breaks at five locations, other access right in/right out only.

Access control is provided for the interchange improvements as depicted in the project Exhibits.

Replace three structures over Blackberry Creek with two structures each.

Blackberry Creek is outside the limits of the proposed interchange improvement.

Accommodate a park-and-ride facility at Interstate 88.

Discussions with Village staff reveal that there is no plan to construct a park-and-ride facility near the interchange.

Kane County Division of Transportation – Illinois 47 Corridor Plan – T.Y. Lin International, Houseseal Lavigne Associates, and SEC Group, Inc. – Completed 2010. The Kane County Division of Transportation has initiated a comprehensive study of the IL RTE. 47 Corridor in Kane and McHenry Counties in cooperation with the McHenry County DOT and the City of Woodstock. This study examined IL Rte. 47 from the Wisconsin State Line to the Kendall County Line. The goal of this study is to provide a vision for the IL Rte. 47 corridor. The study information recommends the construction of a full service interchange for IL Rte. 47 at I-88 and a 2 to 4 lane expansion of IL Rte. 47 through the limits of the Interchange Feasibility Study.


36

Appendix J contains the recommended capital improvements and roadway cross section for IL Rte. 47 in the study area. CMAP – November 13, 2008 Comments to Interchange Volumes Study “The region’s 2030 Regional Transportation Plan supports introducing or expanding expressway and tollway interchanges to improve accessibility and support efficient economic development. This should be accomplished in coordination with local land use plans that recognize the intended role of expressways and tollways to provide long distance regional travel. From the report, I understand that the plans for development in adjacent communities have been considered and are an important basis for this project. This project is also expected to lead to more efficient access to I-88 eastbound from the vicinity of the interchange.”


37

7.0 PROJECT COST AND POTENTIAL FUNDING SOURCES 7.1 Probable Cost of Construction A full service conventional diamond interchange has been identified as the least expensive alternative to accommodate the 2030 projected traffic volumes at the IL Rte. 47 at I-88 interchange. The cost for this interchange alternative in 2009 unit cost dollars is calculated to be $19.7 million. The most expensive option is the SPUI at a cost of $32.4 Million. The probable year of construction for the proposed improvements is 2015. 7.2 Potential Funding Sources The Village has completed this study to justify the interchange for IDOT and the Illinois Tollway. Additionally, they desire funding from both agencies for the interchange improvements, and the cost estimate will be used when securing funding. Possible project funding sources include: The Village of Sugar Grove IDOT – Proposed Highway Improvement FHWA Illinois Tollway Kane County Private developers adjacent to the Tollway

The Village of Sugar Grove has assumed ‘lead agency responsibilities’ in order to pursue and develop a mutually beneficial implementation plan for this project. The Illinois Tollway has indicated that funding commitments for the ultimate improvement would need to be in place prior to beginning any construction. These funding commitments would be based on cost estimates and right-of-way requirements to be determined after an ultimate improvement configuration is agreed upon.


38

8.0 CONCLUSION AND RECOMMENDATIONS 8.1 Impetus for the Interchange A full access interchange at IL Rte. 47 and I-88 will provide safe and efficient access to rapidly growing sections of southern Kane County, the Village of Sugar Grove, and the Village of Elburn. Additionally, interchange improvements will facilitate regional travel by traffic continuing north following the construction of the Prairie Parkway, which is planned with a northern terminus at I-88. The proposed interchange will also safely accommodate design year traffic to and from the east for I-88 at IL Rte. 47. The regional roadway network will function more efficiently if a full interchange is constructed. 8.2 Recommended Interchange Configuration Of the interchange options investigated one alternative best met the needs defined in the feasibility study for the proposed interchange. The study focused on evaluating the degree of feasibility of each alternative through a traffic analysis of the system, right-of-way impacts, structural evaluation, utility impacts, environmental impacts, and construction cost. The Interchange Feasibility Study recommends the Conventional Diamond Interchange as the most viable alternative. The recommendation of the Conventional Diamond Interchange was based on its traffic handling characteristics, low construction costs, and the minimal utility and environmental impacts. The Conventional Diamond Interchange is expected to provide sufficient capacity to manage traffic volumes projected through and the 2030 design year. It meets the purpose of the project which is to provide a safe roadway that will improve connectivity to the interstate network while meeting the development goals of the communities. Construction of the Conventional Diamond Interchange option would cost approximately $19.7 million dollars, which makes it the lowest cost of all alternatives investigated in the design. The lower costs are realized from allowing the existing bridge and parts of the ramps to and from the west to remain. The Conventional Diamond Interchange would primarily be constructed in the existing Tollway right-of-way at IL Rte. 47. Only 2.1 acres of new right-of-way is estimated for the interchange improvement. All except 0.3 acres of the 2.1 acres is owned by Crown Community Development, a developer that fully supports the construction of a full service interchange at IL Rte. 47. The proposed layout would not impact the salt storage yard in the NW quadrant of the interchange and would result in minor impacts to the Tollway storage yard in the NE quadrant of the interchange. The recommendation of this interchange does not preclude the implementation of any of the other interchange designs referenced within this report. The DDI, SPUI, and NE Loop ramp are all considered viable options and will be studied further as a part of the future Phase I interchange study. 8.3 Next Steps Once the feasibility of adding new ramp connections for IL Rte. 47 at I-88 to and from the east is accepted by the Illinois Tollway and IDOT, the next step is a more detailed engineering analysis of the IL Rte. 47 interchange. The Village typically would enter into an agreement with the Tollway and IDOT regarding funding, jurisdictional control, and responsibility for subsequent interchange development. The environmental impacts for the proposed interchange would have to be studied further during Phase I engineering. Once the Phase I engineering study is approved by the controlling agencies, Phase II engineering would begin developing contract


39

plans and specifications for the project while land acquisition occurs. These plans could then be let in a competitive bidding process whereby the lowest responsible contractor is selected. These further engineering studies will verify a final interchange type for the proposed additional ramps.

I-88/Illinois Route 47 Full Interchange - Sugar Grove ... · PDF fileI-88/Illinois Route 47...

Documents

Transcript of I-88/Illinois Route 47 Full Interchange - Sugar Grove ... · PDF fileI-88/Illinois Route 47...