INTERCHANGE OPERATIONAL ANALYSIS REPORT (IOAR ......2001/09/18 · 75/Corkscrew Road interchange are viable based on the conceptual analysis performed to date. E.1.1 Proposal does

INTERCHANGE OPERATIONAL ANALYSIS REPORT (IOAR)

INTERSTATE 75 AT CORKSCREW ROAD (CR 850)

Lee County, Florida

Prepared for

Florida Department of Transportation District One

January 2018

EXECUTIVE SUMMARY I-75/ CORKSCREW ROAD IOAR

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Executive Summary The purpose of this IOAR is to provide the required technical documentation for obtaining FHWA approval for improvements at the I-75/Corkscrew Road interchange in Lee County. The current interchange is a diamond interchange with signal-controlled operation at both ramp terminal intersections. The primary basis for traffic projections in this IOAR is the latest version of the District One Regional Planning Model (D1RPM) which has a base year of 2010 and a cost feasible (forecast) year of 2040. The analysis years for the study include Existing Year 2016, Opening Year 2019, and Design Year 2029. The operational analysis for this study was performed using Highway Capacity Manual (HCM) 2010 procedures and VISSIM microsimulation software. The I-75/Corkscrew Road interchange serves as the primary I-75 access point for the Villages of Estero. The interchange ramp terminal intersections currently experience significant delays and queues for critical left turn movements during peak hours. Two alternatives will be evaluated in this IOAR (Build Alternative and No-Build Alternative). The Build Alternative consists of additional left turn lanes accessing the I-75 on-ramps (resulting in dual left turn lanes in both directions), additional queue storage lanes along the eastbound and westbound approaches to the interchange, extended acceleration/deceleration lanes for ramp merge/diverge operations along I-75 mainline, replacement of high mast lighting at the interchange, and buffered bicycle lanes along Corkscrew Road within the interchange area. The No-Build Alternative would maintain the current facility with no improvements. FDOT is requesting approval of the Build Alternative as part of this IOAR. Currently, the final design phase is funded through FDOT, District One, and is currently ongoing. No right of way acquisition is required for the Build Alternative. Letting for construction is currently targeted for FY 2019. The proposed improvements at the I-75/Corkscrew Road interchange will provide significantly better operations along Corkscrew Road, at the ramp terminal intersections, and at the I-75 ramp junctions with no significant negative impacts. The comparison of the No-Build and Build Alternative shows that the proposed improvements will provide better and safer operating conditions by reducing delay and queuing at the study interchange. These improved operating conditions will result in a reduction of the likelihood of rear-end and sideswipe crashes, resulting in safer conditions compared to the No-Build Alternative. This IOAR has been developed in accordance with FDOT Policy No. 000-525-015: Approval of New or Modified Access to Limited Access Highways on the Strategic Intermodal System (SIS), FDOT Procedure No. 525-030-160: Approval of New or Modified interchange access to limited access facilities on SIS, the Interchange Access Request User’s Guide (2015) and the FDOT’s 2014 Project Traffic Forecasting Handbook (Procedure No. 525-030-120).


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E.1 Compliance with FHWA General Requirements The following requirements serve as the primary decision criteria used in approval of interchange modification projects. Per FHWA’s new policy adopted May 22nd of 2017, responses to the following two policy points are provided to show that the proposed minor modifications to the I-75/Corkscrew Road interchange are viable based on the conceptual analysis performed to date.

E.1.1 Proposal does not adversely impact operational safety of the existing freeway An operational and safety analysis has concluded that the proposed change in access does not have a significant adverse impact on the safety and operation of the Interstate facility (which includes mainline lanes, existing, new, or modified ramps, ramp intersections with crossroad) or on the local street network based on both the current and the planned future traffic projections. The analysis shall, particularly in urbanized areas, include at least the first adjacent existing or proposed interchange on either side of the proposed change in access (23 CFR 625.2(a), 655.603(d) and 771.111(f)). The crossroads and the local street network, to at least the first major intersection on either side of the proposed change in access, shall be included in this analysis to the extent necessary to fully evaluate the safety and operational impacts that the proposed change in access and other transportation improvements may have on the local street network (23 CFR 625.2(a) and 655.603(d)). Requests for a proposed change in access must include a description and assessment of the impacts and ability of the proposed changes to safely and efficiently collect, distribute and accommodate traffic on the Interstate facility, ramps, intersection of ramps with crossroad, and local street network (23 CFR 625.2(a) and 655.603(d)). Each request must also include a conceptual plan of the type and location of the signs proposed to support each design alternative (23 U.S.C. 109(d), and 23 CFR 655.603(d)). The safety analysis performed for this IOAR showed that the most common crash type (rear-end collisions) occurred most frequently near signalized intersections at Three Oaks Parkway and the I-75 ramp terminals. The calculated five-year crash rates at the ramp terminal intersections exceeded statewide averages for similar facilities. This condition is expected to worsen without any improvements to the interchange. The proposed improvements at the I-75 ramp terminals are predicted to improve overall operations and reduce queuing, while also providing increased queue storage for left turn movements onto I-75. These improvements will result in lower intersection delays, and will reduce the likelihood of rear-end and sideswipe crashes that may be caused by excessive queuing and queue spillover into the Corkscrew Road through lanes. Additionally, the recommended improvements to the merge/diverge segments of I-75 will reduce congestion (vehicle density) within the ramp merge/diverge influence areas and help to lower the number of congestion-related crashes within the ramp influence areas. The extended acceleration lanes for the I-75 on-ramps will provide additional time and distance for drivers to accelerate to freeway speeds and to find acceptable gaps in I-75 traffic when merging. This will provide safer travel conditions. The proposed project improvements associated with the Build Alternative will provide better operations and LOS at the ramp terminal intersections and ramp junctions compared to the No-


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Build Alternative. The operational analysis conducted for this project concluded that the proposed modifications would not have an adverse impact on I-75.

E.1.2 A full interchange with all traffic movements at a public road is provided The proposed access connects to a public road only and will provide for all traffic movements. Less than “full interchanges” may be considered on a case-by-case basis for applications requiring special access for managed lanes (e.g., transit, HOVs, HOT lanes) or park and ride lots. The proposed access will be designed to meet or exceed current standards for federal-aid projects on the interstate system (23 CFR 625.2(a), 625.4(a)(2), and 655.603(d)). The proposed improvements will maintain all traffic movements at the study interchange. The Build Alternative will improve ramp terminal intersection operations and ramp merge/diverge operations. The proposed modifications are designed to meet current standards for federal-aid projects on the interstate system and conform to AASHTO design standards.

E.1 Compliance with FHWA General RequirementsE.1.1 Proposal does not adversely impact operational safety of the existing freeway

TABLE OF CONTENTS I-75/ CORKSCREW ROAD IOAR

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Table of Contents EXECUTIVE SUMMARY E-1

E.1.2 A full interchange with all traffic movements at a public road is provided E-3

1.0 INTRODUCTION 1-11.1 Background 1-11.2 Purpose and Need 1-11.3 Project Location 1-2

2.0 METHODOLOGY 2-12.1 Overview 2-12.2 Area of Influence 2-12.3 Analysis Years 2-22.4 Data Collection 2-22.5 Traffic Factors and Characteristics 2-32.6 Level of Service Criteria 2-32.7 Analysis Procedures 2-4

Highway Capacity Manual (HCM) 2-4VISSIM Operational Analysis 2-4

3.0 EXISTING CONDITIONS 3-13.1 Existing Land Use 3-13.2 Existing Transportation Network 3-1

Existing Roadway Network 3-13.3 Existing Year (2016) Traffic Volumes 3-1

48-Hour Bi-Directional Traffic Counts (Date of Count) 3-18-Hour Peak Period Turning Movement Counts (4-hour AM, 4-hour PM) 3-1

3.4 HCM-Based Operational Analysis 3-6Existing Year (2016) Ramp Analysis 3-6

3.5 Microsimulation-Based Operational Analysis 3-6Existing Year (2016) Intersection Analysis 3-6Existing Year (2016) Travel Times 3-7Existing Year (2016) Ramp Terminal Queues 3-8Existing Year (2016) Network-Wide Performance 3-9

3.6 Crash Data and Safety Information 3-93.7 Consistency with Master Plans, LRTP, LGCP and DRIs 3-12

4.0 ALTERNATIVES 4-14.1 No-Build Alternative 4-14.2 Build Alternative 4-14.3 Design Traffic 4-1

5.0 FUTURE TRAFFIC FORECASTING 5-15.1 Socio-Economic and Roadway Network 5-15.2 Historic Growth Trends 5-1

E-2E-2


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5.3 Horizon Year 2040 D1RPM 5-1 5.4 Recommended Growth Rates 5-2 5.5 Development of Design Year (2029) Traffic Volumes 5-2

Design Year (2029) Annual Average Daily Volumes 5-2 Consistency with Adjacent Studies 5-2 Design Year (2029) Directional Design Hour Volumes 5-3 Development of Opening Year (2019) Traffic Volumes 5-5

6.0 EVALUATION OF OPENING YEAR 2019 OPERATIONS 6-1 6.1 Opening Year 2019 Study Intersection Performance 6-1 6.2 2019 Critical Movement Queues 6-3 6.3 2019 Arterial Travel Times 6-4 6.4 Design Year 2019 Network-Wide Performance 6-5

7.0 EVALUATION OF DESIGN YEAR 2029 OPERATIONS 7-1 7.1 Design Year 2029 Study Intersection Performance 7-1 7.2 Design Year 2029 Critical Movement Queues 7-3 7.3 Design Year 2029 Arterial Travel Times 7-4 7.4 Design Year 2029 Network-Wide Performance 7-4 7.5 Safety 7-5 7.6 Alternatives Comparison 7-5

Planning and Environmental Comparison 7-5 Operational Comparisons 7-5

8.0 CONCLUSIONS AND RECOMMENDATIONS 8-1 8.1 Compliance with FHWA General Requirements 8-1

Proposal does not adversely impact operational safety of the existing freeway 8-1 A full interchange with all traffic movements at a public road is provided 8-2

9.0 CONCEPTUAL FUNDING PLAN AND SCHEDULE 9-1


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List of Figures Figure 1-1 Project Location ......................................................................................................... 1-3 Figure 1-2 Project Study Area ..................................................................................................... 1-4 Figure 3-1 Existing Year 2016 AADT Volumes ......................................................................... 3-3 Figure 3-2 Existing Year 2016 Peak Hour Volumes ................................................................... 3-4 Figure 3-3 Existing Year 2016 Lane Configuration .................................................................... 3-5 Figure 4-1 Build Alternative Lane Configuration ....................................................................... 4-3 Figure 4-2 Opening Year (2019) and Design Year (2029) Annual Average Daily Traffic (AADT) Volumes ....................................................................................................................................... 4-4 Figure 5-1 AADT Forecast Comparison - I-75 North of Corkscrew Road ................................. 5-3 Figure 5-2 Design Year (2029) Peak Hour Volumes ................................................................... 5-4 Figure 5-3 Opening Year (2019) Peak Hour Volumes ................................................................ 5-6

List of Tables Table 2-1 Summary of Traffic Factors ....................................................................................... 2-3 Table 3-1 Existing Roadway Network Characteristics ............................................................... 3-1 Table 3-2 Existing Year 2016 Ramp Analysis Summary ........................................................... 3-6 Table 3-3 Existing Year 2016 Intersection Analysis Summary.................................................. 3-7 Table 3-4 Existing Year 2016 Peak Hour Travel Times............................................................. 3-7 Table 3-5 Existing Year 2016 Peak Hour Queue Comparison ................................................... 3-8 Table 3-6 Existing Year 2016 Network-Wide Performance ....................................................... 3-9 Table 3-7 Crash Summary for Overall Project Area ................................................................ 3-10 Table 3-8 Crash Summary for Corkscrew Road ....................................................................... 3-11 Table 3-9 Crash Summary for I-75 Ramps ............................................................................... 3-12 Table 5-1 Project Traffic Growth Rate Information ................................................................... 5-2 Table 6-1 Opening Year 2019 Intersection Analysis Summary ................................................. 6-2 Table 6-2 Opening Year 2019 No-Build Alternative Ramp Analysis Summary ....................... 6-2 Table 6-3 Opening Year 2019 Build Alternative Ramp Analysis Summary.............................. 6-2 Table 6-4 Opening Year 2019 Critical Movement Queue Comparison ..................................... 6-4 Table 6-5 Opening Year 2019 Travel Time Comparison ........................................................... 6-5 Table 6-6 Opening Year 2019 Network-Wide Performance ...................................................... 6-6 Table 7-1 Design Year 2029 Intersection Analysis Summary.................................................... 7-2 Table 7-2 Design Year 2029 No-Build Ramp Analysis Summary ............................................. 7-2 Table 7-3 Design Year 2029 Build Alternative Ramp Analysis Summary ................................ 7-2 Table 7-4 Design Year 2029 Critical Movement Queue Comparison ........................................ 7-3 Table 7-5 Design Year 2029 Travel Time Comparison.............................................................. 7-4 Table 7-6 Design Year 2029 Network-Wide Performance ......................................................... 7-5 Table 7-7 Critical Element Year of Failure Estimates ................................................................ 7-6


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List of Appendices Appendix A – Final MLOU Appendix B – Design Traffic Technical Memorandum Appendix C – VISSIM Existing Conditions Calibration Report Appendix D – VISSIM Output and Analysis Files Appendix E – Traffic Count Data Appendix F – HCS Analysis Files Appendix G – Crash Data Appendix H – Build Alternative Design Concept and Signing Plan Appendix I – D1RPM Model Validation Documentation Appendix J – Volume Development Information Appendix K – Year of Failure Estimates All appendices are provided separately in electronic format.

1.0 INTRODUCTION I-75/ CORKSCREW ROAD IOAR

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1.0 INTRODUCTION

1.1 Background The Florida Department of Transportation (FDOT), District One, requests the Florida Department of Transportation Systems Implementation Office approval of an Interchange Operational Analysis Report (IOAR) for the improvement of the Interstate 75 (I-75) interchange at Corkscrew Road (County Road 850) in Lee County. This IOAR has been developed in accordance with FDOT Policy No. 000-525-015: Approval of New or Modified Access to Limited Access Highways on the Strategic Intermodal System (SIS), FDOT Procedure No. 525-030-160: Approval of New or Modified interchange access to limited facilities on SIS, the Interchange Access Request User’s Guide (2015) and the FDOT’s 2014 Project Traffic Forecasting Handbook (Procedure No. 525-030-120). The I-75 Project Development and Environment (PD&E) Study and the accompanying Systems Interchange Modification Report (SIMR) for this segment of I-75 (completed in 2002) identified the need for interchange improvements at the I-75/Corkscrew Road interchange. The ultimate concept recommended in the SIMR for this interchange was the Single Point Urban Interchange (SPUI). In March 2006, FDOT launched the I-75 Road Expansion Project (IROX) in southwest Florida to provide relief to commuters on I-75. As part of the IROX project, improvements at the I-75/Corkscrew Road interchange included widening the bridges to the inside. The PD&E Study completed in 2002 produced the last document (Type 2 Categorical Exclusion) that was approved by FHWA for this interchange. It was approved on December 30, 2002, which was the date of Location and Design Concept Acceptance (LDCA) by FHWA. Later, a design change reevaluation was prepared in 2010 as part of the design phase, but the project was put on hold prior to FHWA approval. A Design Traffic Technical Memorandum (DTTM) was completed in March 2011 and was updated in January 2015, both of which re-evaluated the ultimate concept recommended in the PD&E and SIMR studies along with other alternatives which included an Improved Diamond Interchange, a Tight Urban Diamond Interchange (TUDI), and a Diverging Diamond Interchange (DDI). This study was initially intended to further evaluate and compare the various alternatives using updated traffic data and microsimulation. The recent assessment of various improvement alternatives has demonstrated that relatively minor capacity and operational enhancements (rather than a reconfiguration to SPUI or DDI) are expected to extend the service life of the existing interchange until at least the year 2029. Therefore, the District has elected to move forward with the implementation of interim improvements for this interchange. This document presents the results of the evaluation of an interim improvement alternative (Build Alternative) and the No-Build Alternative.

1.2 Purpose and Need I-75, a north/south facility, is an integral part of the Strategic Intermodal System (SIS) providing for high-speed, high-volume traffic movements within the State. The 2002 I-75 PD&E Study and accompanying SIMR recommended improvements to the Corkscrew Road interchange. The 2015

1.0 INTRODUCTION I-75/ CORKSCREW ROAD IOAR

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traffic study evaluated the previously proposed SPUI interchange alternative along with several other build alternatives; the result of this study was the recommendation of additional detailed analysis including microsimulation to determine the preferred concept for the I-75/Corkscrew Road interchange. In 2016, a traffic study was initiated with the intent to further evaluate the “ultimate” interchange improvements (evaluating SPUI, DDI and improved diamond alternatives) using a Design Year of 2044 and an Opening Year of 2024. During the course of that study, a determination was made by the District to consider relatively minor “interim” improvements to determine how many years of serviceable life could be gained. A series of interim improvements were evaluated and they were shown to provide acceptable operations through the year 2029. Therefore, a determination was made to move forward with interim improvements at this interchange. The purpose of this IOAR is to evaluate the future traffic operations at the I-75/Corkscrew Road interchange based on the revised population/traffic growth projections, to evaluate the need for the improvements recommended by previous studies, and to determine the preferred configuration for the subject interchange using detailed microsimulation-based analysis. The need for this IOAR is to identify and evaluate the most suitable interchange configuration to meet the demands of future travelers while minimizing project costs and impacts. Traffic analysis from the 2002 PD&E Study as well as the subsequent traffic studies indicate that traffic operations along Corkscrew Road are expected to deteriorate as demand increases within the project study area. The most recent traffic forecast and preliminary analysis indicate that without improvements to the ramp junctions, at least one of the ramp merge/diverge points is expected to fall below LOS D as soon as the year 2025; without ramp terminal intersection improvements, peak hour queues are expected to consistently exceed available storage before the year 2024. Based on existing field observations and the conclusions of the previous traffic studies, it is evident that interchange improvements are needed to accommodate future travel demand.

1.3 Project Location The project study area is located in Lee County, Florida at the junction of I-75 and Corkscrew Road (Milepoint 8.370/mile marker 123). The study area extends along I-75 from south of the southbound on-/northbound off-ramps to north of the southbound off-/northbound on-ramps. Along Corkscrew Road, the study area extends from west of Three Oaks Parkway to east of Ben Hill Griffin Parkway, a distance of approximately 1.9 miles. The project location map is shown in Figure 1-1 and the study area map is shown in Figure 1-2.

Alico Rd

Corkscrew Rd

Bonita Beach Rd SE

BeginEnd

§̈¦75

I-75 at Corkscrew Road IOAR

0 0.45 0.9

Miles

§̈¦75

7.35 Miles

4.32 Miles

I

Project Location Map Figure1-1

! ! ! ! !

!

!

!

!

!

Three Oaks Parkw

ay

Puerto Way

Town C

omm

ons Dr

Puerto LaneEstero Tow

n Com

mons Pl

Corkscrew

Com

mons D

r

Corkscrew Woodlands Blvd

Mirom

ar Design Center Blvd

Mirom

ar Outlets Blvd

Ben Hill Griffin Pkwy

Stoneybrook Golf Blvd

Corkscrew Rd

Corkscrew Rd

§̈¦75

§̈¦75

Project Study AreaI-75 at Corkscrew Road IOAR Figure1-2

Legend

! Study Intersection

Area of Influence

2.0 METHODOLOGY I-75/ CORKSCREW ROAD IOAR

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2.0 METHODOLOGY

2.1 Overview A Methodology Letter of Understanding (MLOU) was prepared for this project and was approved in May 2017. The following sections summarize the methodology as it appears in the MLOU. The Final MLOU document is provided in Appendix A. The methodology used for travel demand forecasting and development of design hour traffic is consistent with the FDOT Project Traffic Forecasting Handbook (2014). Traffic projections were based on a review of historical traffic trends, population forecasts obtained from the Bureau of Economic and Business Research (BEBR) data, and the latest available version of the adopted FDOT District One Regional Planning Model (D1RPM) which has a base year of 2010 and a cost feasible (forecast) year of 2040.

2.2 Area of Influence Along mainline: The study extends along the mainline (I-75) north and south of the study interchange to include all of the Corkscrew Road interchange ramp junctions.

Along crossroads: Along Corkscrew Road, the study area extends from west of Three Oaks Parkway to east of Ben Hill Griffin Parkway. The study includes all signalized and unsignalized intersections within the defined boundary. The ten intersections included within the study area along Corkscrew Road are as follows. Corkscrew Road at:

1. Three Oaks Parkway – signalized 2. Puerto Way/Town Commons Drive – unsignalized 3. Puente Lane/Estero Town Commons Place – unsignalized 4. Corkscrew Commons Drive – unsignalized 5. Corkscrew Woodlands Boulevard – unsignalized 6. I-75 Southbound Ramp Terminal – signalized 7. I-75 Northbound Ramp Terminal – signalized 8. Miromar Design Center Boulevard – unsignalized 9. Miromar Outlets Boulevard – signalized 10. Ben Hill Griffin Parkway/Stoneybrook Golf Boulevard – signalized

The adjacent I-75 interchanges north and south of Corkscrew Road have not been included in the area of influence due to their distance from the subject interchange (see Figure 1-1). The I-75 interchange with Alico Road is approximately 4.32 miles north of Corkscrew Road and the Bonita Beach Road interchange is approximately 7.35 miles south of Corkscrew Road. Due to their distance from the subject interchange, any improvements to the Corkscrew Road interchange are not expected to affect the interchanges at Alico Road and Bonita Beach Road. Additionally, because no I-75 mainline capacity improvements are proposed as part of the Build Alternative, the mainline operations are not evaluated in this study.


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2.3 Analysis Years The following study years have been established for this study:

A. Traffic Forecasting Base year 2010 Horizon year 2040

B. Traffic Operational Analysis Existing year 2016 Opening year 2019 Design year 2029

2.4 Data Collection Various sources were used to collect all necessary traffic, socioeconomic, and physical data used as part of this study. The data sources include, but are not limited to:

A. Transportation System Data Data sources include FDOT Straight Line Diagrams and Roadway Characteristics Inventory (RCI) as well as field observations.

B. Existing and Historical Traffic Data Existing Turning Movement Counts (TMC), machine counts, classification counts and information from the automatic traffic recorder (ATR) sites have been collected for roadway systems within the area of study on a typical weekday following guidelines in the Project Traffic Forecasting Handbook (2014). Traffic data from the permanent traffic monitoring site (PTMS) located west of I-75 on Corkscrew Road were reviewed along with other data from the Florida Transportation Information DVD and existing traffic from other studies in the area. Corridor travel times, ramp terminal intersection queues, and field observations were also collected to aid in the calibration of the existing conditions VISSIM models.

C. Land Use Data Land Use data was obtained from Florida Geographic Data Library (FGDL), Lee County Comprehensive Plan, and approved Planning documents such as Planned Unit Developments (PUDs).

D. Environmental Data Environmental data will be obtained from Lee County, Efficient Transportation Decision Making (ETDM) Environmental Screening Tool (EST), and FGDL.

E. Planned and Programmed Projects Existing plans, programs and project lists were obtained from FDOT, Lee County, Villages of Estero, and the local Metropolitan Planning Organization (MPO) as needed.


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2.5 Traffic Factors and Characteristics The factors used for design traffic analysis include the Standard K, D, DHT and PHF factors. The Standard K is the proportion of the annual average daily traffic (AADT) occurring during the peak hour of the design year, depending upon the area type and facility type. The directional distribution, or D factor, represents the percentage of the two-way peak hour volume that is traveling in the peak direction. Design Hour Trucks (DHT) is the percentage of truck traffic occurring during the peak hours and is typically estimated as half of the 24-hour truck percentage (T24). The FDOT recommended Standard K value for all facilities in ‘transitioning to urbanized areas’ is 9.0%. Therefore, a Standard K value of 9.0% is applicable for I-75 and Corkscrew Road. The traffic factors used in this IOAR are presented in Table 2-1. A Peak Hour Factor (PHF) is not a required input for Corkscrew Road and side streets because those facilities were analyzed using VISSIM, which utilizes a multiple period simulation approach. Additional supporting documentation for the selection of these traffic factors is provided in the project’s Design Traffic Technical Memorandum (included in Appendix B) and the project’s Final MLOU (see Appendix A). Table 2-1 Summary of Traffic Factors

Roadway Standard K D T24 DHT PHF fp** MOCF I-75 9.0% 55% 12% 6% 0.95 1.0 0.91

Corkscrew Road 9.0% 58% 4% 3%* NA 1.0 0.92

Side Streets 9.0 % 58% 4% 3%* NA 1.0 0.92 * A peak hour truck percentage of 3% was selected for Corkscrew Road and the arterial side streets based on the actual peak hour truck percentage observed in the field. This will provide a more conservative analysis than using the typical ½ of the daily percentage which would result in a 2% peak hour truck factor. ** Driver population factor of 1.0 due to majority of drivers being local commuters or otherwise familiar with the area.

2.6 Level of Service Criteria FDOT maintains minimum acceptable operating level of service (LOS) targets for the State Highway System as well as the Strategic Intermodal System (SIS). I-75 is a SIS facility. The term LOS is defined as the system of six designated ranges from “A” (best) to “F” (worst) used to evaluate roadway facility performance. The FDOT minimum acceptable operating LOS targets were used for this IOAR. The LOS targets for major roadways analyzed in this IOAR are summarized below:

• I-75 Ramps: LOS D • Study Intersections: LOS D

Due to methodological differences, specific level of service criteria were not applied to microsimulation-based analysis results. For the signalized intersections, overall delay values greater than or equal to 80 seconds per vehicle was considered excessive.


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2.7 Analysis Procedures

Highway Capacity Manual (HCM) The operational analysis for this study was performed using the Highway Capacity Manual (HCM) 2010. The HCM methodology is generally classified as a series of analytical procedures (flow rate variables) that produce deterministic results (no randomness). Each transportation facility (freeway mainline, freeway ramp, etc.) is analyzed using a unique methodology, which is performed independent of other adjacent facilities. Highway Capacity Manual (HCM) 2010 methodologies were used for the operational analysis of I-75/Corkscrew Road ramp junctions. The operational analysis of the ramp junctions was completed using Highway Capacity Software (HCS) version 6.60 based on HCM 2010.

VISSIM Operational Analysis The VISSIM analysis begins with the development of an existing conditions simulation model that is calibrated to field conditions. Simulation calibration is the process of performing model adjustments to better replicate the local driving behavior and traffic performance. The calibration process typically compares field data (volume, speed, travel time, congestion, etc.) to the simulation output. A model that is appropriately calibrated improves the model’s ability to assess the future conditions of the study area. In this study, the calibration criteria from Federal Highway Administration’s (FHWA) Traffic Analysis Toolbox Volume III: Guidelines for Applying Traffic Microsimulation Modeling Software (2004) report was used as a guide; these criteria are generally consistent with the FDOT Traffic Analysis Handbook. All reasonable efforts were made to calibrate the VISSIM models to the proposed calibration criteria and targets. Documentation of the VISSIM calibration effort is provided in Appendix C. The Opening Year 2019 and Design Year 2029 VISSIM models analyzed three-hour AM and PM peak periods. Peak-hour traffic forecasts were developed using the D1RPM as discussed in Section 5.3. Fifteen-minute flow rates, based on existing peak period volume profiles, were used to develop the three-hour AM and PM peak period models. The Opening Year 2019 and Design Year 2029 simulation model parameters used in the analysis were based on those used for the Existing Year 2016 calibrated model. During the calibration process, a statistical test was used to determine the number of model runs needed for statistical significance of the modeled results. Based on the results of this statistical test, fifteen (15) model iterations with random seeds were used to determine the operational performance of the study area. The following VISSIM Measures of Effectiveness (MOEs) were used to evaluate the network’s operational performance:

• Signalized Intersections o Overall intersection delay

• Unsignalized Intersections o Highest movement delay

• Arterial o Travel Time o Travel Speed


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• Interchange o Critical movement queue lengths

The MOEs listed above were used to compare the operational performance of the No-Build and Build Alternatives. Appendix D contains supplemental simulation output related to the study area performance for each analysis alternative. The following sections provide a summary of the operational performance based on the VISSIM modeling results.

3.0 EXISTING CONDITIONS I-75/ CORKSCREW ROAD IOAR

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3.0 EXISTING CONDITIONS The following sections provide a discussion and evaluation of the existing conditions within the area of influence for the I-75/Corkscrew Road study. This discussion includes the existing roadway characteristics and existing traffic data.

3.1 Existing Land Use Land use directly adjacent to the study interchange consists of developed lands (all four quadrants) consisting primarily of commercial uses including Miromar Outlet Mall and Estero Bay Chevrolet dealership. Residential developments make up the majority of adjacent lands.

3.2 Existing Transportation Network

Existing Roadway Network The existing transportation network within the study area consists of a six-lane interstate freeway and one four-lane divided urban minor arterial. Table 3-1 summarizes the features of the major roadways in the study area including number of lanes, roadway classifications, and primary roadway functions. Table 3-1 Existing Roadway Network Characteristics

Roadway From To Functional Classification

Number of

Lanes

Posted Speed Limit

I-75 South of

Corkscrew Rd North of

Corkscrew Rd Urban-Interstate 6 70 mph

Corkscrew Rd

West of Three Oaks Parkway

East of Ben Hill Griffin Parkway

Urban Minor Arterial 4 45 mph

3.3 Existing Year (2016) Traffic Volumes The locations and dates of traffic counts conducted are contained in the following subsections. Annual Average Daily Traffic Volumes (AADTs) and existing peak hour volumes can be found in Figure 3-1 and 3-2, respectively. The existing conditions intersection lane configurations are depicted in Figure 3-3. Traffic count data is provided in Appendix E. Turning movement counts were conducted from 6:00 to 10:00 am and 3:00 to 7:00 pm during typical weekdays.

48-Hour Bi-Directional Traffic Counts (Date of Count) • Corkscrew Road west of Three Oaks Parkway (1-20-16 through 1-22-16) • Corkscrew Road east of Ben Hill Griffin Parkway (1-20-16 through 1-22-16)

8-Hour Peak Period Turning Movement Counts • Corkscrew Road @ Three Oaks Parkway (4-8-14) • Corkscrew Road @ Town Commons Drive/ Puerto Way (1-20-16)


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• Corkscrew Road @ Puente Lane (1-20-16) • Corkscrew Road @ Corkscrew Commons Drive (1-20-16) • Corkscrew Road @ Corkscrew Woodlands Boulevard (1-20-16) • Corkscrew Road @ I-75 Southbound (1-20-16) • Corkscrew Road @ I-75 Northbound (1-20-16) • Corkscrew Road @ Miromar Design Center Entrance (1-20-16) • Corkscrew Road @ Miromar Outlets Boulevard (1-20-16) • Corkscrew Road @ Ben Hill Griffin Parkway (4-8-14)

8,100

7,900 7,900

8,100

19,00025,000

45,200

45,000 45,000

45,200

30,300 28,400

Three Oaks Pkwy

Puerto WayTown Commons Dr

Estero Town Commons PlPuente Lane

Corkscrew Commons Dr


Miromar Design Center Blvd

Miromar Outlets Blvd

Stoneybrook Golf BlvdBen Hill Griffin Pkwy

Corkscrew RdCorkscrew Rd

LegendExisting Year 2016 AADTX,XXX

Figure3-1

Existing Year 2016Annual Average Daily Traffic (AADT) VolumesI-75 at Corkscrew Road IOAR

Three Oaks Pkwy









164 (

225)

164 (

239)

5 (4)

437 (

273)

49 (1

28)

459 (

278)

215 (

426)

67 (3

17)

879 (

454)

59 (1

59)

1 (25

)

2 (13

)

167 (

138)

438 (466)

54 (227)

301 (720)

18 (39)

11 (43)

9 (9)

90 (212)336 (573)

863 (1,362)

915 (1,587)

504 (1,091)

641 (1,572)

1,060 (1,812)

1,110 (1,892)

1,102 (1,804)

1,101 (1,758)

445 (889)

230 (

132)

245 (

368)

49 (4

8)

10 (6

)

58 (1

02)

89 (323)2 (13)

464 (330)

50 (80)7 (22)

40 (53)

42 (49)

101 (

113)

0 (0)

236 (

588)

40 (103)

457 (445)

51 (36)63 (72)553 (393)

18 (3

8)

2 (2)

413 (

509)

45 (9

0)

21 (1

23)

19 (1

11)

268 (

658)

976 (441)

1,379 (961)

1,446 (1,278)

1,185 (1,003)

973 (926)

1,801 (1,344)

1,761 (1,303)

1,747 (1,366)

1,730 (1,383)

1,055 (689)252 (111)

42 (38)

261 (275)

89 (89)

10 (24)

28 (14)

124 (314)

4,156(3,310)

2,874(4,587)

2,778(4,705)

4,278(3,228)

924 (500) 598 (922)

658 (87

7)

562 (995)

528 (858)

879 (692)

1,043

(693)

921 (775)

LegendAM (PM) PeakHour VolumeX,XXX (X,XXX)

Signalized IntersectionUnsignalized Intersection

Figure3-2

Existing Year 2016Peak Hour VolumesI-75 at Corkscrew Road IOAR

Three Oaks Pkwy








Bonita Beach Rd

Alico Rd


3 >< 3

3 >< 3

1 >

1 >

< 1 < 1

1 >

1 >

< 1< 1Legend


Figure3-3Existing Year 2016 Lane ConfigurationI-75 at Corkscrew Road IOAR

Intersection Lane ConfigurationMainline Lane Configuration1 >


3-6

3.4 HCM-Based Operational Analysis A detailed operational analysis of the Existing Year 2016 using HCM 2010 methodologies was performed for individual ramp junctions. Figures 3-2 and 3-3 show the existing peak hour traffic volumes and lane configurations, respectively, for the I-75 mainline, ramps, and study intersections. Documentation is provided for the existing conditions HCS analysis in Appendix F.

Existing Year (2016) Ramp Analysis The results of the Existing Year 2016 ramp analysis are summarized in Table 3-2. All of the study ramp junctions operate at acceptable LOS in both the AM and PM peak hours. Table 3-2 also shows peak hour volumes at merge and diverge junctions. The ramp analysis results indicated that all four of these ramps are under capacity in 2016. Table 3-2 Existing Year 2016 Ramp Analysis Summary

Interchange Ramp AM Peak Hour PM Peak Hour

Volume Density1 LOS Volume Density1 LOS

I-75/ Corkscrew Rd.

NB Off 658 22.2 C 877 31.3 D NB On 562 17.0 B 995 27.9 C SB Off 1043 30.3 D 693 24.3 C SB On 921 25.1 C 775 20.4 C

1. Density = passenger cars/mile/lane

3.5 Microsimulation-Based Operational Analysis A detailed microsimulation-based analysis of the Existing Conditions was conducted using VISSIM. Three hour AM and PM peak period models were developed and calibrated using field-collected data for the purposes of establishing the existing operational conditions within the study area as well as to use a baseline for developing the future year models. The following sections summarize the results of the VISSIM analysis of Existing Conditions. Additional detail regarding the existing conditions analysis is provided in the “I-75 at Corkscrew Road VISSIM Existing Conditions Model Development and Calibration Report” in Appendix C.

Existing Year (2016) Intersection Analysis The Existing Year 2016 intersection analysis results are summarized in Table 3-3. The intersections were analyzed in VISSIM using existing lane configurations and signal controls. In Existing Year 2016, significant vehicle queuing is occurring for the left turn movements accessing the I-75 on-ramps.


3-7

Table 3-3 Existing Year 2016 Intersection Analysis Summary

Intersection of Corkscrew Road at: Delay (seconds/vehicle)1

AM Peak PM Peak Three Oaks Parkway 35.0 57.1 Puerto Way/Town Commons Drive 8.7 145.7 Puente Lane/Estero Town Commons Place 16.2 232.6 Corkscrew Commons Drive 8.7 9.5 Corkscrew Woodlands Boulevard 17.4 40.9 I-75 Southbound Ramps 22.0 78.6 I-75 Northbound Ramps 43.6 48.9 Miromar Design Center Boulevard 7.8 8.1 Miromar Outlets Boulevard 2.6 6.7 Ben Hill Griffin Parkway 41.0 39.9

1. Overall Delay is reported for the signalized intersections and highest minor street movement (stop controlled) delay is reported for unsignalized intersections

Existing Year (2016) Travel Times Arterial travel times along Corkscrew Road were collected using travel time segments in the Existing Conditions VISSIM models. These travel times were compared to field-collected data as part of the calibration process. Table 3-4 summarizes the Existing Conditions travel time comparison for the AM and PM peak hours. As shown in the table, the simulated arterial travel times were consistent with those collected in the field. Table 3-4 Existing Year 2016 Peak Hour Travel Times

Direction Total

Distance (Miles)

Average Total Travel

Time (Minutes)

15% Range (Minutes) Modeled

Average Travel Time (Minutes)

Threshold Met? Lower

Limit Upper Limit

AM Peak Hour Corkscrew Road Eastbound (West of Three Oaks Pkwy. to

East of Ben Hill Griffin Pkwy.)

1.92 4.03 3.42 4.63 4.20 Yes

Corkscrew Road Westbound (East of Ben Hill Griffin

Pkwy. to West of Three Oaks Pkwy.)

1.92 4.67 3.97 5.37 4.65 Yes

PM Peak Hour Corkscrew Road Eastbound (West of Three Oaks Pkwy. to

East of Ben Hill Griffin Pkwy.)

1.92 6.06 5.15 6.97 6.7 Yes

Corkscrew Road Westbound (East of Ben Hill Griffin

Pkwy. to West of Three Oaks Pkwy.)

1.92 4.13 3.51 4.75 4.72 Yes


3-8

Existing Year (2016) Ramp Terminal Queues Critical movement queues at the study interchange were assessed as part of the Existing Conditions calibration process. Observed queues were recorded for the on-ramp left turns between the ramp terminal intersections and for the off-ramp left turning movements; no significant queueing was observed for any of the right-turning movements at the subject interchange. In the AM peak hour, queuing was observed in the westbound direction for the westbound left to the I-75 southbound on-ramp. During the PM peak hour significant queues were observed for the eastbound left to the I-75 northbound on-ramp. Queues on the off-ramp approaches were not significant and did not impact the I-75 mainline. The primary focus of the calibration was the peak direction (westbound AM, eastbound PM) on-ramp left turn queues. Data collected during the queue study reflected queues that were counted only between the ramp terminal intersections and did not account for queue spillback into the upstream queue storage lanes and beyond. To provide a consistent approach to determining Existing Conditions queues, queue information was extracted from VISSIM using the node output. Node evaluation data for each intersection was extracted, which reports queues up until the edge of the next adjacent node and does not account for queue spillback, similar to how the queue study was conducted. Table 3-5 summarizes the peak hour peak direction on-ramp left turn queues as compared to field observations. Table 3-5 Existing Year 2016 Peak Hour Queue Comparison

Intersection Movement

Observed Queue Length Modeled Queue

Length (ft)

Within Range? Maximum

(ft)

+/- 20% Lower Limit

Upper Limit

AM Peak I-75 SB Ramps WBL 450 360 540 417 Yes

PM Peak I-75 NB Ramps EBL 625 500 750 533 Yes

In addition to quantitative queue comparisons, comparisons between field reviews and visual audits of the VISSIM simulation were conducted to ensure adequate representation of the Existing Conditions within the study area. During field review, queues were observed to spill back from the ramp terminal intersection into the upstream queue storage lanes. This was especially significant in the eastbound direction during the PM Peak period. Queues for the eastbound left onto the I-75 northbound on-ramp were observed to extend beyond the southbound ramp terminal intersection to the full length of the queue storage lane and beyond. Multiple cycle failures were observed at the I-75 southbound ramp terminal intersection and queues for the eastbound left movement were observed to impact adjacent through lane traffic at times. To approximate the actual queue length related to the eastbound left turns, the eastbound through movement queues from consecutive notes were summed; this provides a composite queue length accounting for spillback across several nodes and allows for a better comparison to future queue lengths. Summing the eastbound through queues at the northbound ramp terminal, southbound ramp terminal, and at Corkscrew Woodlands Boulevard results in a maximum eastbound queue of approximately 2,500 feet. This is the approximate distance from the northbound ramp terminal intersection to Estero Town Commons Place. Visual audits of the PM peak period model confirms


3-9

that the simulation adequately reproduces this queue spillback from the northbound ramp terminal intersection through the southbound ramp terminal intersection and beyond. Additional queuing information is provided in Appendix C.

Existing Year (2016) Network-Wide Performance Table 3-6 summarizes the network-wide output for the Existing Conditions. Typically, network-wide output is provided for comparison purposes in future conditions. The Existing Conditions network-wide output is provided for consistency with results provided in later sections. Table 3-6 Existing Year 2016 Network-Wide Performance

AM Peak PM Peak Total Delay (hr) 393 876 Latent Delay (hr) 0.46 18.4 Latent Demand 0.1 0.1

Total Travel Time (hr) 4,202 5,736 Total Stops 22,294 46,598

Vehicles Arrived 28,065 37,168 Note: Network-wide output represents the performance of the study area over the entire 3-hour peak period.

3.6 Crash Data and Safety Information Crash data for the study area was obtained from Florida Signal Four Analytics for the years 2012 through 2016. The crash data included information including date of crash, location, number of vehicles involved, type of crash, number of injuries and/or fatalities, cause of crash, and estimated economic loss. The crash analysis results reveal that there were a total of 657 crashes within the study area during this five-year period (2012-2016). Of these 657 crashes, rear-end collisions were the most common crash type, accounting for 54% of total crashes. Together, left-turn, sideswipe, head-on, and angle collisions made up 25% of all crashes. Various other types of collisions made up the remaining crashes. Table 3-7 summarizes the crash data for the entire study area. Table 3-8 summarizes the crash data along Corkscrew Road and at street and ramp termini intersections. Table 3-9 summarizes the crash data for the I-75 merge/diverge ramps and area of influence. Over the five-year period, one fatal rear end crash occurred within the project area on southbound I-75 approximately 1,000 feet north of Corkscrew Road. Three crashes involving pedestrians/bicyclists occurred over the study period. The first involved a pedestrian who was struck from behind by an unknown vehicle at the intersection of Corkscrew Road and Miromar Outlets Boulevard. The pedestrian was treated for injuries. The second involved a bicyclist heading south on Three Oaks Parkway who was struck by a vehicle making a left turn from Corkscrew Road onto Three Oaks Parkway. The bicyclist was not treated for injuries. Finally, a third crash involved a bicyclist traveling eastbound on Corkscrew Road. A vehicle traveling north on Corkscrew Woodlands Boulevard failed to notice the bicyclist crossing the intersection as he pulled out to make a left turn. The pedestrian was transported to Gulf Coast Hospital for injuries. Each of the pedestrian/bicycle crashes resulted from negligent behavior at various locations; therefore, no infrastructure/safety improvements would have likely prevented these crashes. The


3-10

most common crash type (rear end collisions) mostly occurred near signalized intersections, where queuing is a contributing factor. The improvement recommendations presented in this document are intended to improve ramp terminal intersection operations and reduce queue lengths. Table 3-7 Crash Summary for Overall Project Area

Crash Type 2012 2013 2014 2015 2016 2011 - 2016 Percent Rear End 35 55 75 86 101 352 54% Left Turn 4 12 9 14 14 53 8%

Other 7 15 20 20 18 80 12% Head On 13 19 5 0 1 38 6%

Sideswipe 1 5 7 18 15 46 7% Angle 6 6 7 4 7 30 5%

Right Turn 3 2 2 3 2 12 2% Unknown 3 4 3 2 2 14 2% Off Road 4 4 2 8 5 23 4% Rollover 1 3 1 0 1 6 1% Bicycle 1 1 0 0 0 2 0%

Pedestrian 1 0 0 0 0 1 0% Total 79 126 131 155 166 657 100%


3-11

Table 3-8 Crash Summary for Corkscrew Road

Corkscrew Road Intersection at:

Thr

ee O

aks P

kwy

Tow

n C

omm

ons D

r/Pu

erto

W

ay

Pue

nte

Ln/

Est

ero

Tow

n C

omm

ons P

l

Cor

kscr

ew C

omm

ons D

r

Cor

kscr

ew W

oodl

ands

Blv

d

I75

SB R

amps

I75

NB

Ram

ps

Des

ign

Cen

ter

Ent

ranc

e

Mir

omar

Out

let E

ntra

nce

Ben

Hill

Gri

ffin

Pkw

y a

nd S

tone

ybro

ok G

olf R

d

Crash Type

5-Year Total

5-Year Total

5-Year Total

5-Year Total

5-Year Total

5-Year Total

5-Year Total

5-Year Total

5-Year Total

5-Year Total

Angle 4 0 6 0 7 0 0 0 4 9 Rear End 83 6 3 5 7 61 56 3 17 35 Head On 3 1 0 1 0 1 5 0 22 3 Left Turn 12 1 5 2 7 4 3 0 13 6 Sideswipe 9 1 2 0 1 4 3 0 5 11 Pedestrian 0 0 0 0 0 0 0 0 1 0 Right Turn 4 0 1 0 0 1 4 0 1 1

Bicycle 1 0 0 0 1 0 0 0 0 0 Other 12 1 1 5 1 3 0 0 20 8

Rollover 1 0 0 0 0 1 0 0 1 0 Off Road 2 0 0 0 0 1 0 0 0 2 Unknown 2 0 0 0 0 2 0 0 2 4

Total 133 10 18 13 24 78 71 3 86 79 The crashes summarized below in Table 3-9 occurred along the ramp roadways or within the ramp merge/diverge influence area, defined as 1,500 feet downstream or upstream of a ramp merge or diverge point, respectively. The project’s recommended improvements to the merge/diverge operations along I-75 will reduce congestion (vehicle density) within the ramp merge/diverge influence areas and help to lower the number of congestion-related crashes including rear-end collisions. Crash rate calculations were conducted for the two ramp terminal intersections at the study interchange. The calculated crash rate at the southbound ramp terminal over a five-year period (2012-2016) was 1.076 crashes per million entering vehicles (MEV). The crash rate at the northbound ramp terminal during the same period was 1.028 crashes per MEV. The Florida statewide average crash rate for a similar facility (i.e., a three-legged intersection of a four lane divided roadway with raised median) was 0.361 over a similar period (2011-2015), which is significantly lower than the calculated crash rates at the ramp terminal intersections. Crash rate calculations and supporting documentation can be found in Appendix G.


3-12

Table 3-9 Crash Summary for I-75 Ramps

I-75

SB

Off

Ram

p

I-75

SB

Div

erge

A

rea

of In

fluen

ce

I-75

SB

On

Ram

p

I-75

SB

Mer

ge

Are

a of

Influ

ence

I-75

NB

Off

Ram

p

I-75

NB

Div

erge

A

rea

of In

fluen

ce

I-75

NB

On

Ram

p

I-75

NB

Mer

ge

Are

a of

Influ

ence

Crash Type

5-Year Total

5-Year Total

5-Year Total

5-Year Total

5-Year Total

5-Year Total

5-Year Total

5-Year Total

Angle 0 0 0 0 0 0 0 0 Rear End 1 33 6 3 0 9 5 19 Head On 0 1 0 1 0 0 0 0 Left Turn 0 0 0 0 0 0 0 0 Sideswipe 0 4 0 1 0 1 3 1 Pedestrian 0 0 0 0 0 0 0 0 Right Turn 0 0 0 0 0 0 0 0

Bicycle 0 0 0 0 0 0 0 0 Other 0 6 1 0 1 8 3 10

Rollover 0 0 0 0 0 1 1 1 Off Road 0 6 0 0 1 2 1 8 Unknown 1 0 0 0 0 2 0 1

Total 2 50 7 5 2 23 13 40 A summary of the crash data and a map depicting crash locations are provided in Appendix G.

3.7 Consistency with Master Plans, LRTP, LGCP and DRIs This IOAR considers all programmed and planned roadway improvements in the area. These capacity improvements would be consistent with those specified in the regional transportation plans including the following:

• FDOT five year work program • FDOT SIS plans • Lee County MPO Comprehensive Plan

The need for improvements at the study interchange has been identified in the Lee County MPO’s 2040 LRTP. Interchange improvements are included in the LRTP Cost Feasible Plan by the year 2025 (Preliminary Engineering only). The construction phase is not currently included in the Cost Feasible Plan.

The Department will coordinate the funding of this IOAR with the MPO should the plans require amendment to be consistent with the recommended alternative.

4.0 ALTERNATIVES I-75/ CORKSCREW ROAD IOAR

4-1

4.0 ALTERNATIVES As part of this IOAR, the following alternatives have been considered and evaluated:

• No-Build Alternative • Build Alternative

The alternatives were analyzed to assess their effectiveness in meeting the future travel demand needs of the I-75/Corkscrew Road interchange as well as the physical and social impacts, and safety and environmental considerations associated with each alternative.

4.1 No-Build Alternative The No-Build Alternative provides a baseline for comparison to the Build Alternative. This alternative represents the existing physical and operational conditions within the study area. Since the basis for any interchange proposal is based on a comparison of the No-Build and Build Alternative, identification of the network that is considered in the No-Build Alternative in each analysis year is required. As part of the cost feasible improvements in Lee County MPO’s LRTP, Corkscrew Road is to be widened from two lanes to four lanes east of Ben Hill Griffin Parkway and this represents the only difference between existing conditions and the No-Build Alternative. The No-Build intersection lane configurations within the study area are the same as existing conditions (as shown in Figure 3-3).

4.2 Build Alternative One Build Alternative has been developed and evaluated in this IOAR. The lane configuration for the Build Alternative in shown in Figure 4-1. The Build Alternative includes the addition of an eastbound left-turn lane and westbound left-turn lane from Corkscrew Road to the northbound and southbound I-75 on-ramps, respectively, providing dual left turn lanes in each direction. The Build Alternative also provides additional queue storage for these left turn movements as well as extended ramp merge and diverge distances for all four ramp junctions with I-75. The Build Alternative interchange design concept is provided in Appendix H. Because the Build Alternative maintains the basic interchange configuration (i.e., diamond), the proposed signing plan will remain mostly consistent with the existing signing. A conceptual signing plan for the Build Alternative is also provided in Appendix H. The Build Alternative provides seven-foot-wide buffered bicycle lanes along Corkscrew Road throughout the interchange. Other than the improved bicycle lanes, the pedestrian and bicycle features will remain basically the same as in the existing condition. As shown above in Table 3-8, there were no reported crashes involving pedestrians or cyclists at the I-75 ramp terminal intersections over the five-year study period.

4.3 Design Traffic Due to the nature of the (interim) improvements evaluated in this study, a Design Year of 2029 was established for the evaluation of alternatives in accordance with the latest Interchange Access Request User’s Guide (2015). Design traffic volumes for the Build and No-Build Alternatives for future years 2019 and 2029 were developed as described in Section 5.5. The future year AADTs (No-Build and Build Alternatives) for 2019 and 2029 were developed by the application of approved growth rates to existing AADTs and are shown in Figure 4-2. Peak hour traffic forecasts

4.0 ALTERNATIVES I-75/ CORKSCREW ROAD IOAR

4-2

were developed initially by applying the Standard K and D factors listed in Table 2-1 to AADT volumes and then adjusting for reasonableness and for volume balancing. The technical memorandum documenting the forecast year model adjustments, recommended growth rates, and traffic forecasts is included in the project DTTM provided in Appendix B. Additional documentation of the development of design traffic is provided in Appendix J.

Three Oaks Pkwy









3 >< 3

3 >< 3

1 >

< 1 < 1

1 >

Legend


Figure4-1Build Lane ConfigurationI-75 at Corkscrew Road IOAR

Intersection Lane ConfigurationMainline Lane Configuration1 >

a.8,700b.10,700

a.8,500b.10,500 a.8,500

b.10,500

a.8,700b.10,700

a.30,600b.37,600

a.32,200b.38,200

a.20,400b.25,200

a.26,500b.31,500

a.47,900b.56,900

a.47,700b.56,700

a.47,700b.56,700

a.47,900b.56,900

Three Oaks Pkwy









a. X,XXX Opening Year 2019 AADT

Figure4-2Opening Year (2019) and Design Year (2029)

Annual Average Daily Traffic (AADT) VolumesI-75 at Corkscrew Road IOAR

b. X,XXX Design Year 2029 AADT

Legend

5.0 FUTURE TRAFFIC FORECASTING I-75/ CORKSCREW ROAD IOAR

5-1

5.0 FUTURE TRAFFIC FORECASTING The purpose of this section is to document the travel demand modeling and development of future year Annual Average Daily Traffic (AADT) and Directional Design Hour Volumes (DDHVs) for the interchange and the adjacent arterial roadways and intersections. Due to the nature of the (interim) improvements, a Design Year of 2029 was established for this study. The forecasting effort included an assessment of validation accuracy of the base year (2010) model, a review of network connectivity for reasonable loadings, a review of socioeconomic data (ZDATA), and a review of model consistency with the District One Regional Planning Model (D1RPM).

5.1 Socio-Economic and Roadway Network Future traffic projections for this project were developed using the current adopted FDOT D1RPM. The D1RPM is based on the Florida Standard Urban Transportation Modeling Structure (FSUTMS) using Citilabs’ CUBE software. The most recently adopted Cost Affordable (CA) roadway network is included in this model. The D1RPM has a base validation year of 2010 and has a future horizon year of 2040. Model validation included adjustments to AT, FT, and centroid loadings. Socioeconomic data changes were made to Traffic Analysis Zones (TAZs) 4000 and 4003, located north of Corkscrew Road and east of Ben Hill Griffin Parkway, to reflect future land use information including the planned Corkscrew Farms and Wild Blue developments. The D1RPM was validated for the base year 2010 by FDOT and met the required regional model validation criteria. Documentation of the validation effort is provided in Appendix I.

5.2 Historic Growth Trends A review of historic traffic counts for FDOT count stations along I-75 and Corkscrew Road was conducted. Annual historic trend growth rates were calculated using FDOT’s Traffic Trend Analysis tool. The trends analysis indicates that the average annual growth rate for I-75 north of Corkscrew Road was 2.5% per year and was 2.93% south of Corkscrew Road. The annual growth rate was found to be 1.16% on the I-75 interchange ramps and 2.88% along Corkscrew Road between I-75 and Three Oaks Parkway. Additional information regarding historic trends is provided in Appendix B.

5.3 Horizon Year 2040 D1RPM Prior to obtaining future traffic volumes from the D1RPM, the 2040 D1RPM was reviewed to verify that nearby major development land uses and cost feasible projects were adequately represented in the model ZDATA (socioeconomic data) and network, respectively. Some minor adjustments were made to the ZDATA to account for future developments that were recently approved (Corkscrew Farms and Wild Blue developments). Additional information regarding the ZDATA adjustments is provided in Appendix I. The 2040 AADT volumes along I-75, Corkscrew Road and the side streets located within the I-75/Corkscrew Road project study area were obtained from the 2040 D1RPM using a MOCF factor of 0.91 along I-75 and 0.92 for Corkscrew Road and the connecting side streets in accordance with FDOT’s Florida Transportation Information database.


5-2

5.4 Recommended Growth Rates In order to develop project traffic growth rates to be used in the development of future volumes, several data sources were evaluated including model volumes, historical count records, and socioeconomic data. The D1RPM was used to calculate annual traffic growth rates for the I-75 study corridor. Daily model volumes from the 2010 Base and 2040 Cost Affordable model runs were compared for this calculation. The Bureau of Economic and Business Research (BEBR) population projections were also reviewed and compared to other forecasting methods to develop the project traffic growth rates. These growth rates were applied to Existing Year 2016 AADTs to develop future year AADTs. The growth rate comparison and approved growth rates are displayed in Table 5-1. Because these various growth rates were derived linearly, they were also applied linearly. Table 5-1 Project Traffic Growth Rate Information

1 Growth rates based on BEBR Population Projections Volume 49, Bulletin 174, January 2016 2 Average of the I-75 ramps with positive historic growth

5.5 Development of Design Year (2029) Traffic Volumes

Design Year (2029) Annual Average Daily Volumes The Design Year (2029) AADT volumes were developed using the approved growth rates presented above. Manual adjustments were made based on reasonableness checks, balancing and comparison to existing year (2016) AADT. Figure 4-1 depicts the future AADT volumes for this study.

Consistency with Adjacent Studies The study AADT volumes were compared to the traffic forecasts from a previous interchange traffic study conducted by FDOT in 2014 (see Figure 5-1). As shown below, the previous forecast volumes are very consistent with the current forecast, even though different travel demand models were used.

Roadway Segment2010 D1RPM

AADT2040 D1RPM

AADT2016 Count vs. 2040 D1RPM

2010 D1RPM vs. 2040 D1RPM

Historic Trend BEBR1 Approved Growth

Rate

I-75 Mainline north of Corkscrew 66185 108651 0.86% 2.14% 2.50% 2.34%I-75 Mainline south of Corkscrew 64876 117720 1.25% 2.72% 2.93% 2.34%I-75 Ramps - - 2.72% - 1.16%2 2.34% 2.5%Corkscrew between I-75 and Three Oaks 32703 49575 2.01% 1.72% 2.88% 2.34%Corkscrew west of Three Oaks 19731 30849 1.48% 1.88% - 2.34%Corkscrew between I-75 and Ben Hill 26242 43165 2.06% 2.15% - 2.34%Corkscrew east of Ben Hill - - 3.30% - - 2.34%

2.0%

2.0%

2.5%


5-3

Figure 5-1 AADT Forecast Comparison - I-75 North of Corkscrew Road

Design Year (2029) Directional Design Hour Volumes The Design Year (2029) DDHVs were developed by multiplying the 2029 AADT volumes by the approved design traffic factors. The existing year (2016) turning movement volumes were entered into a volume development spreadsheet and used as a basis for developing the design year (2029) turning movement volumes. A manual smoothing process was then performed to ensure that traffic flows were balanced between adjacent intersections:

For consistency of volume flows between count locations. To obtain peak hour volumes that closely represents approved K-factor and D-

factor. To balance the approach and departure volumes associated with adjacent

intersections. To increase individual movement volumes that were estimated to be lower than the

existing volumes. To reduce individual turning movement volumes that were estimated to be

significantly higher than the existing volumes. After the DDHVs were balanced, the design factors were checked to verify that they were maintained within acceptable ranges as specified in the FDOT Project Traffic Forecasting Handbook (2014). Documentation of the development of future DDHVs is provided in Appendix J. It includes a series of spreadsheets that show link-level development of DDHVs and all of the intersection turning volume development (including adjustments). Design Year (2029) peak hour volumes are depicted in Figure 5-2.

R² = 0.9888

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

2010 2015 2020 2025 2030 2035 2040 2045 2050

AADT

Year

AADT for I-75 North of Corkscrew Road

Current Study

Previous Study

Three Oaks Pkwy









290 (

495)

90 (3

65)

1,165

(605

)

75 (2

00)

15 (3

0)

10 (2

0)

210 (

175)

215 (

300)

215 (

315)

10 (1

0)

675 (

335)

65 (1

70)

580 (

350)

710 (555)

85 (270)

495 (1,000)

25 (50)

15 (55)

15 (15)

115 (265)550 (685)

1,405 (1,630)

1,475 (1,885)

845 (1,205)

1,125 (1,890)

1,670 (2,220)

1,735 (2,320)

1,720 (2,210)

1,715 (2,160)

690 (1,095)145 (390)

15 (30)

615 (440)

65 (100)10 (30)

50 (65)

55 (60)

310 (

155)

385 (

510)

60 (6

0)

15 (1

0)

75 (1

30)

25 (5

0)

15 (1

5)

645 (

710)

70 (1

10)

30 (1

50)

30 (1

35)

415 (

810)

135 (

150)

0 (0)

295 (

740)

55 (135)

605 (590)

70 (45)85 (85)745 (465)1,325 (505)

1,870 (1,105)

1,960 (1,470)

1,535 (1,090)

1,315 (1,010)

2,410 (1,570)

2,355 (1,530)

2,330 (1,615)

2,325 (1,635)

1,425 (820)335 (145)

55 (50)

425 (380)

115 (100)

15 (30)

35 (20)

165 (370)

5,450(4,700)

4,700(5,450)

4,590(5,610)

5,610(4,590)

0 (0) 0 (0)

1,030

(1,220)

920 (1,380)

0 (0)0 (0)

1,380

(920)

1,220 (1,030)



Figure5-2

Design Year 2029Peak Hour VolumesI-75 at Corkscrew Road IOAR


5-5

Development of Opening Year (2019) Traffic Volumes The Opening Year (2019) AADTs and DDHVs were developed using the linear interpolation of Design Year (2029) and Existing Year (2016) volumes and historic growth trends. The DDHVs for Opening Year (2019) are shown in Figure 5-3. Reasonable consistency checks were also conducted for Opening Year volumes similar to the Design Year Volumes.

Three Oaks Pkwy









240 (

460)

70 (3

40)

945 (

485)

65 (1

70)

10 (2

5)

5 (15

)

175 (

145)

175 (

240)

175 (

255)

5 (5)

565 (

290)

55 (1

40)

485 (

295)

600 (485)

75 (240)

395 (810)

20 (40)

10 (45)

10 (10)

95 (225)465 (600)

1,185 (1,420)

1,250 (1,650)

740 (1,100)

960 (1,655)

1,400 (1,915)

1,455 (2,000)

1,445 (1,905)

1,435 (1,855)

575 (935)120 (335)

10 (25)

500 (355)

55 (85)5 (25)

40 (55)

45 (50)

255 (

140)

310 (

415)

50 (5

0)

10 (5

)

60 (1

10)

110 (

120)

0 (0)

250 (

625)

20 (4

0)

10 (1

0)

520 (

575)

60 (9

5)

25 (1

30)

25 (1

20)

345 (

695)

45 (110)

490 (475)

55 (40)65 (75)605 (420)1,080 (470)

1,530 (1,030)

1,600 (1,370)

1,255 (1,060)

1,075 (1,000)

1,965 (1,445)

1,915 (1,400)

1,905 (1,470)

1,895 (1,485)

1,160 (740)270 (120)

45 (40)

345 (310)

100 (95)

10 (25)

30 (15)

135 (340)

4,590(3,950)

3,950(4,590)

3,860(4,720)

4,720(3,860)

0 (0) 0 (0)

830 (99

0)

740 (1,120)

0 (0)0 (0)

1,120

(740)

990 (830)



Figure5-3

Opening Year 2019Peak Hour VolumesI-75 at Corkscrew Road IOAR

6.0 EVALUATION OF OPENING YEAR OPERATIONS I-75/ CORKSCREW ROAD IOAR

6-1

6.0 EVALUATION OF OPENING YEAR 2019 OPERATIONS This section documents the future conditions within the I-75/Corkscrew area of influence for the Opening Year 2019 No-Build and Build Alternatives. The No-Build Alternative assumes the existing physical and operational conditions remain in place without improvement.

6.1 Opening Year 2019 Study Intersection Performance The performance of the study intersections was evaluated using VISSIM. The intersections’ demand volumes are identical for the No-Build and Build Alternatives. The basic configuration of the interchange is the same for the No-Build and Build Alternatives. However, the Build Alternative provides dual left turn lanes and extended queue storage for movements accessing the I-75 on-ramps. Additionally, the Build Alternative provides improved ramp merge/diverge operations by extending the acceleration and deceleration lanes. Due to severe congestion along Corkscrew Road in the No-Build scenario, very few vehicles were able to proceed from the stop-controlled side streets. This resulted in unrealistic delays for these movements. To provide more realistic driving behaviors, priority rules were implemented along Corkscrew Road to ensure that gaps were available for side street vehicles to proceed into the east-west traffic flow. This best represents the cooperative driving behaviors of vehicles in severely congested conditions. Because of this, some of the delays for the unsignalized intersections may be lower in the future No-Build conditions than in the Existing Conditions. Differences in delay values help to illustrate the overall level of congestion within the study area along Corkscrew Road and shows the impact of the proposed improvements on the roadway network. Synchro was used as a preliminary tool to optimize signal timing for the Opening Year 2019 demand volumes. All reasonable attempts were made to reduce delays through the modification of signal timings in the network in the No-Build conditions. However, due to significant congestion along the arterial in both directions, some intersections still experienced significant delays. The Opening Year 2019 intersection delay results are summarized in Table 6-1. Additional detail for the intersection analysis is provided in Appendix D. In the Opening Year 2019, five of the 10 study area intersections are expected to operate with excessive delay (>80 seconds per vehicle) during the PM peak hour under the No-Build condition. These excessive delays are primarily due to queuing that occurs along the arterial because of the limited capacity at the ramp terminal intersections. With the proposed improvements of the Build Alternative, all study intersections operate with acceptable levels of delay during both the AM and PM peaks.


6-2

Table 6-1 Opening Year 2019 Intersection Analysis Summary

No-Build Build Intersection

Corkscrew Road @ Delay (seconds/vehicle)1 Delay (seconds/vehicle)1 AM Peak PM Peak AM Peak PM Peak

Three Oaks Parkway 37.1 125.9 36.5 44.6 Puerto Way/Town Commons Drive 10.2 30.0 11.2 12.1 Puente Lane/Estero Town Commons Place 23.6 58.4 24.3 27.0 Corkscrew Commons Drive 9.5 9.8 9.1 10.0 Corkscrew Woodlands Boulevard 23.7 37.6 23.2 27.6 I-75 Southbound Ramps 33.9 80.5 28.9 29.5 I-75 Northbound Ramps 31.5 208.2 27.7 37.5 Miromar Design Center Boulevard 6.7 7.4 6.4 8.9 Miromar Outlets Boulevard 6.6 122.1 5.6 10.1 Ben Hill Griffin Parkway 42.9 168.4 41.4 35.8 1. Overall Delay is reported for the signalized intersections and highest minor street movement (stop controlled) delay is

reported for unsignalized intersections

Ramp Analysis The Opening Year 2019 ramp analysis results from HCS 2010 are summarized in Tables 6-2 and 6-3. The results of the operational analysis show that all the study ramp junctions operate at an acceptable LOS (D or better) under both the 2019 No-Build and Build scenario Table 6-2 Opening Year 2019 No-Build Alternative Ramp Analysis Summary

Interchange Ramp AM Peak PM Peak


I-75/ Corkscrew

Rd.

NB Off 830 28.2 D 990 31.6 D NB ON 740 22.9 C 1120 28.3 D SB Off 1120 32.5 D 740 27.6 C SB On 990 27.4 C 830 23.8 C

1. Density = passenger cars/mile/lane Table 6-3 Opening Year 2019 Build Alternative Ramp Analysis Summary



I-75/ Corkscrew

Rd.

NB Off 830 16.3 B 990 19.6 B NB ON 740 18.6 B 1120 24.1 C SB Off 1120 20.5 C 740 15.6 B SB On 990 22.7 C 830 18.9 B



6-3

6.2 2019 Critical Movement Queues One of the primary concerns for this project was the interchange’s ability to accommodate the heavy left turn demand for the I-75 ramp terminal intersections. In the Existing Condition, eastbound and westbound queues were observed in the field to exceed the available queue storage thus impacting the arterial through movements. The primary focus of the Build Alternative is to address the capacity constraints of these movements and alleviate arterial queueing along Corkscrew Road caused by the heavy left turning movements at the I-75 on-ramps. A critical part of this analysis is determining the queue storage needs along the arterial. Since the distance between the ramp terminal intersections is relatively finite due to bridge infrastructure, the emphasis was placed on the queue storage lanes upstream of the on-ramp movements. The queue lengths for the critical eastbound and westbound left turning movements were assessed using VISSIM queue counters which were placed at the stop bar of the queue storage lanes. Focusing on these locations allowed for the analysis to directly identify the necessary length of the queue storage lanes. Ninety-fifth percentile (95%) queues were estimated by sampling the queue once per cycle during the peak hour. During the AM peak, cycle lengths were 120 seconds, 150 second cycle lengths were used in the PM peak; this resulted in 30 samples per iteration during the AM peak and 24 samples per iteration during the PM peak. These individual observations were used to create a sample size of 450 observations for the AM and 360 observations for the PM. Maximum queues are reported for the off-ramp movements to ensure that these queues do not back up onto the freeway mainline. When comparing queues between the Existing Year and the Opening Year, it is important to note that there are differences in the ways the queues are reported. As noted in Section 3.6.3, the queue information used for calibration was collected using the node output at the ramp terminal intersections; this was done for consistency with the data collected during the queue study where queue information did not account for queue spillback through multiple intersections. As noted above, future year queue analyses utilize queue counters specifically to account for queue spillback through multiple intersections to determine queue storage needs. It is also important to note that in the Existing Condition, left turn volumes were at or near capacity for the single lane left turns at the I-75 on-ramps. With the 2-2.5% growth in traffic between the Existing Year and the Opening Year 2019, these on-ramp movements are not substantially over capacity in the No-Build scenario. This causes a cascading effect throughout the peak period which does not recover by the end of the simulation. These two factors are the primary cause for the significant difference in queue lengths when comparing Existing Year 2016 and Opening Year 2019 No-Build critical movement queues. The Opening Year 2019 queue comparison is summarized in Table 6-4. As shown in the table, with optimized signal timing, the existing storage is able to accommodate the Opening Year 2019 queues during the AM peak. However, during the PM peak, the left turn queues are expected to exceed the available storage capacity causing system-wide implications in the No-Build condition. The queues reported for the PM peak are indicative of the cascading effect of vehicles destined for downstream left turn bays blocking upstream through traffic.


6-4

Queues are significantly shorter under the Build Alternative due to the increased capacity provided for queue storage as well as the proposed dual left turn lanes accessing the freeway on-ramps. Freeway off-ramp queues are not expected to extend to the mainline in either analysis alterative.

Table 6-4 Opening Year 2019 Critical Movement Queue Comparison

Location Movement No-Build Queue (ft)

Build Queue (ft)

Existing Available Storage

(ft) AM Peak

I-75 SB Ramp Terminal EB Left 493 177 620

SBL 144 142 690 SBR 283 311 680

I-75 NB Ramp Terminal WB Left 368 126 730

NBL 219 222 690 NBR 146 140 700

PM Peak

I-75 SB Ramp Terminal EB Left 6,921 348 620

SBL 222 220 690 SBR 145 139 680

I-75 NB Ramp Terminal WB Left 6,862 189 730

NBL 308 321 690 NBR 202 195 700

6.3 2019 Arterial Travel Times Peak-hour travel time and travel speed output was obtained along Corkscrew Road for the No-Build and Build Alternatives. This data was used as an additional tool to assess the benefits of the proposed improvements at the ramp terminal intersections. Table 6-5 provides a comparison between the No-Build and Build travel times and speeds for the Opening Year 2019. During the AM peak, the Build Alternative provided a 2% reduction in travel time in the eastbound direction and a 6% reduction in travel time in the westbound direction. Average speeds along Corkscrew Road were similar for the No-Build and Build Alternatives in both the eastbound and westbound directions during the AM peak. During the PM peak, the Build Alternative provided a 46% reduction in travel time for the eastbound direction and an 80% reduction in travel time for the westbound direction. Average speeds along eastbound Corkscrew Road improved from 15 mph to 27 mph, and westbound average speeds improved from 5 mph to 24 mph under the Build Alternative.


6-5

Table 6-5 Opening Year 2019 Travel Time Comparison

Direction Location No-Build Build % Change

Travel Time (Travel Speed)

Travel Time (Travel Speed) Travel Time

AM Peak Eastbound – West of Three Oaks Pkwy to East of Ben Hill Griffin Pkwy

4.32 minutes (27 mph)

4.22 minutes (27 mph) -2%

Westbound – East of Ben Hill Griffin Pkwy to West of Three Oaks Pkwy



PM Peak Eastbound – West of Three Oaks Pkwy to East of Ben Hill Griffin Pkwy


4.23 minutes (27 mph) -46%



4.77 minutes (24 mph) -80%

6.4 Design Year 2019 Network-Wide Performance Table 6-6 summarizes the network-wide performance results for the No-Build and Build Alternatives during the 2019 AM and PM peak periods. Comparison of the alternatives shows that the Build consistently exhibits better performance than the No-Build in terms of delay, travel time, number of stops, and latent demand. In terms of total delay, the Build Alternative provides a 2% reduction during the AM peak and a 66% reduction in the PM peak. Latent delay and latent demand are reduced by nearly 100% during the PM peak. Total travel time is reduced by 1% during the AM peak and 18% during the PM peak under the Build Alternative; while total stops are reduced by 2% and 66% during the AM and PM peak, respectively. These network-wide benefits reinforce the results discussed in the previous sections which indicate that the Build Alternative provides a significant benefit over the No-Build during the Opening Year 2019.


6-6

Table 6-6 Opening Year 2019 Network-Wide Performance

AM Peak PM Peak No-Build Build % Change No-Build Build % Change

Total Delay (hr) 549 539 -2% 2,089 716 -66% Latent Delay (hr) 0.20 0.21 2% 898 0.25 -100% Latent Demand 0 0.1 0% 565 0.4 -100%

Total Travel Time (hr) 5,356 5,322 -1% 7,483 6,144 -18% Total Stops 27,745 27,088 -2% 101,420 34,198 -66%

Vehicles Arrived 33,503 33,504 0% 39,036 40,083 3% Note: Network-wide output represents the performance of the study area over the entire 3-hour peak period.

7.0 EVALUATION OF DESIGN YEAR OPERATIONS I-75/ CORKSCREW ROAD IOAR

7-1

7.0 EVALUATION OF DESIGN YEAR 2029 OPERATIONS

7.1 Design Year 2029 Study Intersection Performance The performance of the study intersections was evaluated using VISSIM. The intersections’ demand volumes are identical between the No-Build and Build Alternatives. Differences in delay values help to illustrate the overall level of congestion within the study area along Corkscrew Road and shows the impact of the proposed improvements on the roadway network. Synchro was used as a preliminary tool to optimize signal timing for the Design Year 2029 demand volumes. All reasonable attempts were made to reduce delays through the modification of signal timings in the network in the No-Build conditions. However, due to significant congestion along the arterial in both directions, some intersections still experienced significant delays. Similar to the No-Build scenario, in the future Build scenario, priority rules were implemented along Corkscrew Road to ensure that gaps were available for side street vehicles to proceed into the east-west traffic flow. This best represents the cooperative driving behaviors of vehicles in congested conditions. Because of this, some of the delays for the unsignalized intersections may be lower in the future Build conditions than in the Existing Conditions. The Design Year 2029 intersection delay results are summarized in Table 7-1. Additional detail for the intersection analysis is provided in Appendix D. In the Design Year 2029, five of the 10 study area intersections are expected to operate with excessive delay (>80 seconds per vehicle) during the PM peak hour under the No-Build condition. These excessive delays are primarily due to queuing that occurs along the arterial because of the limited capacity at the ramp terminal intersections. During the AM peak hour, the Corkscrew Road intersection with Ben Hill Griffin Parkway is expected to operate with excessive delay in both the No-Build and Build Alternatives. This is primarily due to significant turning volumes (northbound left and southbound right) combined with heavy westbound demand, which results in high delays for several movements at the intersection. With the proposed improvements of the Build Alternative, all remaining study intersections operate with acceptable levels of delay during both the AM and PM peaks.


7-2

Table 7-1 Design Year 2029 Intersection Analysis Summary

No-Build Alternative Build Alternative Intersection

Corkscrew Road @ Delay (seconds/vehicle)1 Delay (seconds/vehicle)1

AM Peak PM Peak AM Peak PM Peak Three Oaks Parkway 42.9 465.3 42.6 50.8 Puerto Way/Town Commons Drive 62.4 36.5 66.9 15.7 Puente Lane/Estero Town Commons Place 47.6 69.7 55.1 27.6 Corkscrew Commons Drive 38.0 11.5 47.8 11.7 Corkscrew Woodlands Boulevard 54.7 34.9 47.1 45.4 I-75 Southbound Ramps 49.9 86.3 39.4 36.6 I-75 Northbound Ramps 53.5 193.2 32.2 43.4 Miromar Design Center Boulevard 7.5 9.0 7.1 9.0 Miromar Outlets Boulevard 7.8 146.7 7.0 10.5 Ben Hill Griffin Parkway 90.1 300.5 82.1 37.6

1. Overall Delay is reported for the signalized intersections and highest minor street movement (stop controlled) delay is reported for unsignalized intersections

Ramp Analysis The Design Year 2029 No-Build ramp analysis results are summarized in Table 7-2. The results of the HCS 2010 capacity analysis show that two of the four study ramp junctions are predicted to operate at an unacceptable LOS for at least one of the peak hours under 2029 No-Build conditions. Table 7-2 Design Year 2029 No-Build Ramp Analysis Summary



I-75/ Corkscrew

Rd.

NB Off 1030 32.1 D 1220 35.8 E NB ON 920 27.1 C 1380 33.5 D SB Off 1380 36.8 E 920 31.5 D SB On 1220 32.4 D 1030 28.1 D

1. Density = passenger cars/mile/lane The Design Year 2029 ramp analysis results are summarized in Table 7-3. The results of the operational analysis show that all of the ramp junctions are predicted to operate at an acceptable LOS under 2029 Build Alternative. Table 7-3 Design Year 2029 Build Alternative Ramp Analysis Summary



I-75/ Corkscrew

Rd.

NB Off 1030 20.2 C 1220 23.8 C NB ON 920 22.9 C 1380 29.4 D SB Off 1380 24.8 C 920 19.5 B SB On 1220 27.8 C 1030 23.4 C



7-3

7.2 Design Year 2029 Critical Movement Queues Similar to the Opening Year, the queue lengths for the critical eastbound and westbound left turning movements were assessed using VISSIM queue counters in the Design Year 2029. Ninety-fifth percentile (95%) queues were estimated by sampling the queue once per cycle during the peak hour. During the AM peak, cycle lengths were 120 seconds, 150 second cycle lengths were used in the PM peak; this resulted in 30 samples per iteration during the AM peak and 24 samples per iteration during the PM peak. These individual observations were used to create a sample size of 450 observations for the AM and 360 observations for the PM. Maximum queues are reported for the off-ramp movements to ensure that these queues do not back up onto the freeway mainline. The Design Year 2029 queue comparison is summarized in Table 7-4. As shown in the table, the existing storage is unable to accommodate the Design Year 2029 left turn queues in both the AM and PM peaks for the No-Build Alternative. By the design year, left turn queues are expected to exceed the available storage capacity causing system-wide implications in the No-Build condition. The queues reported for the PM peak are indicative of the cascading effect of vehicles destined for downstream left turn bays blocking upstream through traffic. Queues are significantly shorter under the Build Alternative due to the increased capacity provided for queue storage as well as the proposed dual left turn lanes for the freeway on-ramps. Freeway off-ramp queues are not expected to extend to the mainline in either analysis alterative. Table 7-4 Design Year 2029 Critical Movement Queue Comparison

Location Movement No-Build Queue (ft)

Build Queue (ft)

Existing Available Storage

(ft) AM Peak

I-75 SB Ramp Terminal EB Left 949 200 620

SBL 157 154 690 SBR 445 567 680


NBL 260 258 690 NBR 173 162 700

PM Peak

I-75 SB Ramp Terminal EB Left 8,780 436 620

SBL 274 273 690 SBR 157 170 680


NBL 363 361 690 NBR 226 249 700


7-4

7.3 Design Year 2029 Arterial Travel Times Peak-hour travel time and travel speed output was obtained along Corkscrew Road for the No-Build and Build Alternatives. This data was used as an additional tool to assess the benefits of the proposed improvements at the ramp terminal intersections. Table 7-5 provides a comparison between the No-Build and Build travel times and speeds for the Design Year 2029. During the AM peak, the Build Alternative provided a 5% reduction in travel time in the eastbound direction and a 6% reduction in travel time in the westbound direction. Average speeds along Corkscrew Road were similar for the No-Build and Build Alternatives in both the eastbound and westbound directions during the AM peak. During the PM peak, the Build Alternative provided a 62% reduction in travel time for the eastbound direction and a 91% reduction in travel time for the westbound direction. Average speeds along eastbound Corkscrew Road improved from 9 mph to 25 mph, and westbound average speeds improved from 2 mph to 23 mph under the Build Alternative. Table 7-5 Design Year 2029 Travel Time Comparison

Direction Location

No-Build Build % Change Travel Time

(Travel Speed) Travel Time

(Travel Speed) Travel Time

AM Peak Eastbound – West of Three Oaks Pkwy to East of Ben Hill Griffin Pkwy






PM Peak Eastbound – West of Three Oaks Pkwy to East of Ben Hill Griffin Pkwy


4.58 minutes (25 mph) -62%




7.4 Design Year 2029 Network-Wide Performance Table 7-6 summarizes the network-wide performance results for the No-Build and Build Alternatives during the 2029 AM and PM peak periods. Comparison of the alternatives shows that the Build consistently exhibited better performance than the No-Build in terms of delay, travel time, number of stops, and latent demand during the Design Year. In terms of total delay, the Build Alternative provides an 8% reduction during the AM peak and a 75% reduction in the PM peak. Latent delay is reduced by 37% during the AM Peak and nearly 100% during the PM peak. Latent demand is reduced by nearly 100% during the PM peak. Total travel time is reduced by 1% during the AM peak and 26% during the PM peak under the Build Alternative; while total stops are reduced by 10% and 77% during the AM and PM peak, respectively. These network-wide benefits reinforce the results discussed in the previous sections which indicate that the Build Alternative provides a significant benefit over the No-Build during the Design Year 2029.


7-5

Table 7-6 Design Year 2029 Network-Wide Performance

AM Peak PM Peak No-Build Build % Change No-Build Build % Change

Total Delay (hr) 967 892 -8% 3,904 966 -75% Latent Delay (hr) 3.69 2.32 -37% 6,401 0.50 -100% Latent Demand 0.07 0.1 0% 4,102 0.0 -100%

Total Travel Time (hr) 6,637 6,563 -1% 9,966 7,390 -26% Total Stops 47,952 43,291 -10% 181,787 42,127 -77%

Vehicles Arrived 39,838 39,853 0% 42,268 47,146 12% Note: Network-wide output represents the performance of the study area over the entire 3-hour peak period.

7.5 Safety Historical crash data was summarized in Section 3.6. The No-Build Alternative will not improve traffic operations or safety. Because the Build Alternative provides improved intersection operations and additional queue storage for critical left turn movements, the Build Alternative will help to reduce traffic congestion along Corkscrew Road during peak periods. The improvements will result in lower intersection delays, thereby reducing the likelihood of rear-end and sideswipe crashes that may be caused by excessive queuing and queue spillover into the Corkscrew Road through lanes. Additionally, improvements to ramp merge/diverge operations will also tend to reduce the likelihood of crashes along I-75 at the Corkscrew Road interchange ramp junctions by providing additional acceleration/deceleration lanes at all four interchange ramps. The extended acceleration lanes for the I-75 on-ramps will provide additional time and distance for drivers to accelerate to freeway speeds and to find acceptable gaps in I-75 traffic when merging.

7.6 Alternatives Comparison The No-Build Alternative and the Build Alternative were compared and a summary is provided in the sections below.

Planning and Environmental Comparison The No-Build Alternative will have no environmental impacts. Special considerations were taken in developing and evaluating the Build Alternative to avoid and minimize the environmental impacts associated with this project to the greatest extent practicable. The Build Alternative will have no significant impacts to air quality. The Build Alternative is not expected to result in any significant environmental impacts. The Build Alternative will have no impact on schools and churches, or historical/archeological sites within the vicinity of the I-75/Corkscrew Road study interchange. Any environmental impacts will be identified during the project re-evaluation conducted during the design phase.

Operational Comparisons This section compares the traffic operational performance of the No-Build and Build Alternatives. The proposed improvements at the I-75/Corkscrew Road interchange will provide significantly improved ramp terminal intersection operations with minimal negative impacts. The proposed modifications have no traffic or operational impacts to the adjacent interchanges.


7-6

In Design Year 2029, there are significant operational deficiencies at the interchange for the No-Build Alternative. The ramp terminal intersections and some nearby intersections along Corkscrew Road perform below the standard of LOS D. Drastic reductions in queue lengths are also apparent between the No-Build and Build Alternatives. Significant queueing issues occur along Corkscrew Road at the ramp terminal intersections, with worst-case queues of 6,876 feet and 8,780 feet at the northbound and southbound ramp terminal intersections, respectively. These queues are reduced to approximately 287 and 436 feet, respectively, by the improvements incorporated in the Build Alternative. The Build Alternative also improves both the travel time along Corkscrew Road and network-wide performance. In conclusion, the comparison of the No-Build and Build Alternatives shows that the proposed improvements provide enhanced traffic operations at the ramp terminal intersections, on the interchange ramps, and along Corkscrew Road. The Build Alternative thus postpones the necessity of a major reconstruction of the I-75/Corkscrew Road interchange. A ‘year of failure’ analysis was also conducted for the critical elements to estimate when operations will fall below the LOS targets (for the Build Alternative) and is shown in Table 7-7. The following table summarizes the analysis. The estimated ‘year of failure’ for ramps was determined by incrementally increasing traffic volumes in accordance with the project’s growth rate (e.g., 2.5% for ramps) until the operations exceeded LOS D. Similarly for intersections, VISSIM analysis was conducted for various future years (beyond 2029) to identify when peak hour intersection delays would exceed 55.0 seconds per vehicle (i.e., LOS E or worse). More detail related to the ‘year of failure’ estimation is provided in Appendix K. Table 7-7 Critical Element Year of Failure Estimates

Roadway Component Estimated

Year of Failure

Signalized Ramp Terminal Intersections 2032 I-75 Ramp Merge/Diverge Operations 2037

8.0 CONCLUSIONS AND RECOMMENDATIONS I-75/ CORKSCREW ROAD IOAR

8-1

8.0 CONCLUSIONS AND RECOMMENDATIONS The proposed improvements at the ramp terminal intersections at the I-75/Corkscrew Road interchange will provide traffic relief and enhance safety within the area of influence by reducing delay and queueing along Corkscrew Road. The No-Build Alternative evaluation shows that it is not in conformance with the long range transportation plans for the region and will not provide adequate capacity for the travel demand at the I-75/Corkscrew Road interchange. The Build Alternative is expected to provide improved operations along Corkscrew Road, at the I-75 ramp terminal intersections, and the I-75 mainline/ramp junctions in the Design Year 2029. This report supports the conclusion that interim interchange improvements, associated with the Build Alternative, will benefit both the interstate and regional transportation systems. No potential environmental fatal flaws have been identified for the proposed improvements. Based on the evaluations of the No-Build and Build Alternatives, the Build Alternative is recommended as the Preferred Alternative for approval in this study. The District will continue to monitor the performance of the interchange after interim improvements are implemented and will evaluate the ultimate improvements in the future when appropriate.

8.1 Compliance with FHWA General Requirements The following requirements serve as the primary decision criteria used in approval of interchange modification projects. Per FHWA new policy adopted May 22nd of 2017, responses to the following two policy points are provided to show that the proposed minor modifications to the I-75/Corkscrew Road interchange are viable based on the conceptual analysis performed to date.

Proposal does not adversely impact operational safety of the existing freeway An operational and safety analysis has concluded that the proposed change in access does not have a significant adverse impact on the safety and operation of the Interstate facility (which includes mainline lanes, existing, new, or modified ramps, ramp intersections with crossroad) or on the local street network based on both the current and the planned future traffic projections. The analysis shall, particularly in urbanized areas, include at least the first adjacent existing or proposed interchange on either side of the proposed change in access (23 CFR 625.2(a), 655.603(d) and 771.111(f)). The crossroads and the local street network, to at least the first major intersection on either side of the proposed change in access, shall be included in this analysis to the extent necessary to fully evaluate the safety and operational impacts that the proposed change in access and other transportation improvements may have on the local street network (23 CFR 625.2(a) and 655.603(d)). Requests for a proposed change in access must include a description and assessment of the impacts and ability of the proposed changes to safely and efficiently collect, distribute and accommodate traffic on the Interstate facility, ramps, intersection of ramps with crossroad, and local street network (23 CFR 625.2(a) and 655.603(d)). Each request must also include a conceptual plan of the type and location of the signs proposed to support each design alternative (23 U.S.C. 109(d), and 23 CFR 655.603(d)).

8.0 CONCLUSIONS AND RECOMMENDATIONS I-75/ CORKSCREW ROAD IOAR

8-2

The safety analysis performed for this IOAR showed that the most common crash type (rear-end collisions) occurred most frequently near signalized intersections at Three Oaks Parkway and the I-75 ramp terminals. As discussed in Section 3.7, the calculated five-year crash rates at the ramp terminal intersections exceeded statewide averages for similar facilities. This condition is expected to worsen without any improvements to the interchange. The proposed improvements at the I-75 ramp terminals are predicted to improve overall operations and reduce queuing, while also providing increased queue storage for left turn movements onto I-75. These improvements will result in lower intersection delays, and will reduce the likelihood of rear-end and sideswipe crashes that may be caused by excessive queuing and queue spillover into the Corkscrew Road through lanes. Additionally, the recommended improvements to the merge/diverge segments of I-75 will reduce congestion (vehicle density) within the ramp merge/diverge influence areas and help to lower the number of congestion-related crashes within the ramp influence areas. The extended acceleration lanes for the I-75 on-ramps will provide additional time and distance for drivers to accelerate to freeway speeds and to find acceptable gaps in I-75 traffic when merging. This will provide safer travel conditions. The proposed project improvements associated with the Build Alternative will provide better operations and LOS at the ramp terminal intersections and ramp junctions compared to the No-Build Alternative. The operational analysis conducted for this project concluded that the proposed modifications would not have an adverse impact on I-75.

A full interchange with all traffic movements at a public road is provided The proposed access connects to a public road only and will provide for all traffic movements. Less than “full interchanges” may be considered on a case-by-case basis for applications requiring special access for managed lanes (e.g., transit, HOVs, HOT lanes) or park and ride lots. The proposed access will be designed to meet or exceed current standards for federal-aid projects on the interstate system (23 CFR 625.2(a), 625.4(a)(2), and 655.603(d)). The proposed improvements will maintain all traffic movements at the study interchange. The proposed improvements will improve ramp terminal intersection operations and ramp merge/diverge operations. The proposed modifications are designed to meet current standards for federal-aid projects on the interstate system and conform to AASHTO design standards.

9.0 CONCEPTUAL FUNDING PLAN AND SCHEDULE I-75/ CORKSCREW ROAD IOAR

9-1

9.0 CONCEPTUAL FUNDING PLAN AND SCHEDULE Funding for this IOAR is available through the FDOT, District One. Funding for final design of the interim interchange improvements is also available through FDOT, District One. The preliminary Long Range Estimate (LRE) totals approximately $5 million for the Build Alternative. The LRE is provided in Appendix H. The design phase began in 2017. The expected completion date of the IOAR is late 2017. Letting for construction is currently targeted for FY 2019.

Documents

INTERCHANGE OPERATIONAL ANALYSIS REPORT (IOAR ......2001/09/18 · 75/Corkscrew Road interchange are viable based on the conceptual analysis performed to date. E.1.1 Proposal does