DRAFT Step 3 Roundabout Evaluation

Transcription

1 DRAFT Step 3 Roundabout Evaluation Geometric and Operational Analysis SR 655 (Recker Highway) at Thornhill Road Polk County, Florida Financial Management Number: Federal-Aid Project Number: N/A District 1 August 2017 Date Fl. Professional Engineer #73812 Michael F. Sasse, PE Patel, Greene & Associates, PLLC 400 W. Morse Blvd., Suite 103 Winter Park, Florida Certificate of Authorization No

2 FPID SR 655 (Recker Highway) Submitted By: Patel, Greene & Associates, PLLC Date: August 2017 TABLE OF CONTENTS Step 3 Roundabout Summary Report 1 Fastest Path Calculations 2-3 Roundabout Concept 4 Fastest Paths Analysis 5-7 WB-62FL Analysis 8-10 Stopping Sight Distance 11 Intersection Sight Distance BACKGROUND AND SUPPORT INFORMATION Appendix A-A Appendix B-B Appendix C-C Appendix D-D Step 1 & Step 2 Roundabout Evaluation Roundabout Movement Summary NCHRP 672 Reference Materials Wisconsin DOT: Creating Roundabout Fastest Paths (Spline Curves) in Microstation Version 8i

3 FLORIDA DEPARTMENT OF TRANSPORTATION STEP 3 ROUNDABOUT SUMMARY REPORT Prepared by: Financial Project No: FAP No.: County: Date Prepared: Project Name: State Road: Intersecting Road: Michael Sasse, PE N/A Polk County August 2017 SR 655 Thornhill Road PURPOSE AND NEED The Florida Department of Transportation is conducting an Environmental Impact Report for SR 655 (Recker Highway) in Polk County, FL. As part of this assessment, and in accordance with Section of the PPM, Volume 1, a roundabout alternative at the intersection of Thornhill Road must be evaluated as part of this reconstruction project. Roundabouts encourage lower speeds on the approach to and within the circulatory roadway, thereby enhancing safety. Step 1 - Roundabout Screening Summary: Results from the Step 1 screening showed that a roundabout at Thornhill Road is a viable alternative. Based on the favorable results of the screening criteria the District Traffic Operations and District Design Engineer have approved the decision to advance the roundabout to a Step 2 b/c Evaluation. Step 2 - Roundabout b/c Evaluation: Two different alternatives were evaluated during the Step 2 analysis. The benefit to cost ratio for roundabout Alt 1 and Alt 2 are 4.3 and 4.4 respectively showing that a roundabout has a higher benefit (in terms of safety) than a signalized intersection. The District Traffic Operations Engineer and District Design Engineer approved the decision to advance the roundabout screening to Step 3. Upon further review by the Department, it was determined to evaluate Alt 2 for Geometric and Operational Analysis. OPERATIONAL ANALYSIS RESULTS Direction Street Name No. Entry Lanes Control Delay (s) LOS SB (AM) SR 655 (Recker Highway) A NB (AM) SR 655 (Recker Highway) A WB (AM) Thornhill Road C SB (PM) SR 655 (Recker Highway) A NB (PM) SR 655 (Recker Highway) A WB (PM) Thornhill Road C GEOMETRIC PERFORMANCE CHECK RESULTS Swept Path of Design Vehicle Accommodated yes no Intersection Sight Distance Satisfied yes no Fastest Path Operating Speed between 20 and 25 mph yes no Fastest Path Operation Speed between 25 and 30 mph for multilane roundabouts (per NCHRP 672) Advance Roundabout to Final Design District Traffic Operations Engineer Date: yes and no District Design Engineer Date Page 1

4 FASTEST PATH CALCULATIONS Project: SR 655 (Recker Highway) at Thornhill Road FPID: Date: 08/01/2017 Designer: Michael F. Sasse, PE Exhibit 6 46 from NCHRP 672 illustrates the five critical path radii that must be checked for each approach. R1, the entry path radius, is the minimum radius on the fastest through path prior to the entrance line. R2, the circulating path radius, is the minimum radius on the fastest though path around the central island. R3, the exit path radius, is the minimum radius on the fastest though path into the exit. R4, the left turn path radius, is the minimum radius on the path of the conflicting left turn movement. R5, the right turn path radius, is the minimum radius on the fastest path of a right turning vehicle. It is important to note that these vehicular path radii are not the same as the curb radii. The R1 through R5 radii measured in this procedure represent the vehicle centerline in its path though the roundabout. NCHRP 672 Exhibit 6 47 Page 2

5 SR 655 (Recker Highway) at Thornhill Road Roundabout Fastest Path Performance Check Approach Eastbound (Thornhill Rd.) Northbound (SR 655) Critical Path Critical Path Radius (FT) Vehicle Speed in MPH (NCHRP Eq 6 2) Max Entry Speed between mph (NCHRP Ex 6 47) R YES R R3 N/A N/A R R R R R R4 N/A N/A R Dist. between mid. R2 & and crosswalk location at R3 Vehicle Exit Speed in MPH (NCHRP Eq 6 4) N/A N/A YES R1 R2 Westbound N/A R3 R4 R5 Southbound (SR 655) R1 R2 R3 R4 R N/A N/A YES Page 3

6 1" = 60' N S R 10 ' R 1 20' 2 2 ' 2 2 ' 7 ' ' 7 ' 2 2 ' ' R ' 100 ' 5' 11 ' 14 R R ' 70 R 7' 1 6 ' R ' 14 22' ' 1 4 ' 10' 7' ' 80 R 1 10' 11' 22' 0' 10 SR ' 1 1 ' 5 1 ' 1 1 D R H T H N R O L IL REVISIONS DATE DESCRIPTION DATE STATE OF FLORIDA DESCRIPTION DEPARTMENT OF TRANSPORTATION ROAD NO. COUNTY SHEET SR 655 AT THORNHILL RD ROUNDABOUT CONCEPT SR 655 NO. FINANCIAL PROJECT ID POLK Mike.Sasse 8/17/2017 3:14:41 PM 4 C:\Users\mike.sasse\Desktop\ Recker Hwy\roadway\PLANRD00.DGN

7 5' 5' SR 655 N R4 = 65 FT V = 16 MPH Feet 5' 5' R1 = 290 FT V = 28 MPH 5' R2 = 78 FT V = 17 MPH 5' 5' 5' SR 655 5' 5' R3 = 350 FT V = 30 MPH 5' THORNHILL RD SOUTHBOUND APPROACH DATE DESCRIPTION REVISIONS DATE DESCRIPTION STATE OF FLORIDA DEPARTMENT OF TRANSPORTATION SR 655 AT THORNHILL RD SHEET NO. ROAD NO. SR 655 COUNTY POLK FINANCIAL PROJECT ID FASTEST PATHS 5 Mike.Sasse 8/20/2017 9:34:30 PM C:\Users\mike.sasse\Desktop\ Recker Hwy\roadway\PLANRD01.DGN

8 5' SR 655 N Feet 5' 5' R5 = 113 FT V = 20 MPH R4 = 67 FT V = 16 MPH 5' 5' R2 = 80 FT V = 17 MPH 5' 5' SR 655 5' 5' THORNHILL RD R1 = 220 FT V = 25 MPH 5' 5' EASTBOUND APPROACH DATE DESCRIPTION REVISIONS DATE 5' DESCRIPTION STATE OF FLORIDA DEPARTMENT OF TRANSPORTATION SR 655 AT THORNHILL RD SHEET NO. ROAD NO. SR 655 COUNTY POLK FINANCIAL PROJECT ID FASTEST PATHS 6 Mike.Sasse 8/20/2017 9:34:31 PM C:\Users\mike.sasse\Desktop\ Recker Hwy\roadway\PLANRD02.DGN

9 5' 5' SR 655 R3 = 689 FT V = 38 MPH N Feet R2 = 350 FT V = 30 MPH 5' 5' R1 = 226 FT V = 25 MPH 5' SR 655 5' 5' 5' 5' THORNHILL RD 5' R5 = 325 FT V = 29 MPH NORTHBOUND APPROACH DATE DESCRIPTION REVISIONS DATE DESCRIPTION STATE OF FLORIDA DEPARTMENT OF TRANSPORTATION SR 655 AT THORNHILL RD SHEET NO. ROAD NO. SR 655 COUNTY POLK FINANCIAL PROJECT ID FASTEST PATHS 7 Mike.Sasse 8/20/2017 9:34:31 PM C:\Users\mike.sasse\Desktop\ Recker Hwy\roadway\PLANRD03.DGN

10 (c) 2016 Transoft Solutions, Inc. All rights reserved. (c) 2016 Transoft Solutions, Inc. Al rights reserved. WB- 62L FL PPM 2013 (US) 1" = 60' WB- 62L FL PPM 2013 (US) N SR 655 SR 655 (c) 2016 Transoft Solutions, Inc. All rights reserved. WB-62L FL PPM 2013 (US) THORNHILL RD WB-62L (c) 2016 Transoft Solutions, Inc. All rights reserved. FL PPM 2013 (US) DATE DESCRIPTION REVISIONS DATE DESCRIPTION STATE OF FLORIDA DEPARTMENT OF TRANSPORTATION ROAD NO. COUNTY FINANCIAL PROJECT ID SR 655 POLK SR 655 AT THORNHILL RD WB-62FL ANALYSIS SHEET NO. 8 Mike.Sasse 8/17/2017 3:09:21 PM C:\Users\mike.sasse\Desktop\ Recker Hwy\roadway\PLANRD04.DGN

11 FL PPM 2013 (US) (c) 2016 Transoft Solutions, Inc. All rights reserved. WB-62L (c) 2016 Transoft Solutions, Inc. All rights reserved. FL PPM 2013 (US) P (c) 2016 Transoft Solutions, Inc. All rights reserved. AASHTO 2011 (US) WB-62L FLPPM 2013 (US) (c) 2016 Transoft Solutions, Inc. All rights reserved. (c) 2016 Transoft Solutions, Inc. Al rights reserved. AASHTO 2011 (US) (c) 2016 Transoft Solutions, Inc. Al rights reserved. 1" = 60' N WB- 62L SR 655 P SR 655 WB-62L FLPPM 2013 (US) THORNHILL RD DATE DESCRIPTION REVISIONS DATE DESCRIPTION STATE OF FLORIDA DEPARTMENT OF TRANSPORTATION ROAD NO. COUNTY FINANCIAL PROJECT ID SR 655 POLK SR 655 AT THORNHILL RD WB-62FL ANALYSIS SHEET NO. 9 Mike.Sasse 8/17/2017 3:09:21 PM C:\Users\mike.sasse\Desktop\ Recker Hwy\roadway\PLANRD05.DGN

12 WB-62L (c) 2016 Transoft Solutions, Inc. Al rights reserved. FLPPM 2013 (US) (c) 2016 Transoft Solutions, Inc. All rights reserved. FLPPM 2013 (US) 1" = 60' N SR 655 SR 655 WB-62L WB-62L (c) 2016 Transoft Solutions, Inc. Al rights reserved. FL PPM 2013 (US) THORNHILL RD WB-62L (c) 2016 Transoft Solutions, Inc. All rights reserved. FL PPM 2013 (US) DATE DESCRIPTION REVISIONS DATE DESCRIPTION STATE OF FLORIDA DEPARTMENT OF TRANSPORTATION ROAD NO. COUNTY FINANCIAL PROJECT ID SR 655 POLK SR 655 AT THORNHILL RD WB-62FL ANALYSIS SHEET NO. 10 Mike.Sasse 8/17/2017 3:09:22 PM C:\Users\mike.sasse\Desktop\ Recker Hwy\roadway\PLANRD06.DGN

13 P AASHTO 2011 (US) P AASHTO 2011 (US) P AASHTO 2011 (US) AASHTO 2011 (US) 1" = 60' AASHTO 2011 (US) P SR 655 N CIRCULATOR SPEED = 17 MPH PER R4 FASTEST PATH ANALYSIS SSD = 90.4 FT SR SOUTHBOUND APPROACH DESIGN SPEED = 35 MPH STOPPING SIGHT DISTANCE PER NCHRP 672 (EQ 6-5) SSD = FT SR NORTHBOUND APPROACH DESIGN SPEED = 35 MPH STOPPING SIGHT DISTANCE PER NCHRP 672 (EQ 6-5) SSD = FT P AASHTO 2011 (US) P P AASHTO 2011 (US) SR 655 SR EASTBOUND APPROACH DESIGN SPEED = 35 MPH STOPPING SIGHT DISTANCE PER NCHRP 672 (EQ 6-5) SSD = FT THORNHILL RD P AASHTO 2011 (US) P AASHTO 2011 (US) SSD ON THE APPROACHES AND CIRCULATORY ROADWAY DATE DESCRIPTION REVISIONS DATE DESCRIPTION STATE OF FLORIDA DEPARTMENT OF TRANSPORTATION ROAD NO. COUNTY FINANCIAL PROJECT ID SR 655 POLK SR 655 AT THORNHILL RD STOPPING SIGHT DISTANCE SHEET NO. 11 Mike.Sasse 8/22/2017 1:33:37 PM C:\Users\mike.sasse\Desktop\ Recker Hwy\roadway\PLANRD07.DGN

14 P AASHTO 2011 (US) P AASHTO 2011 (US) 1" = 60' SR 655 N SR SOUTHBOUND APPROACH CHECK OF TWO CONFLICTING TRAFFIC STREAMS: ENTERING STREAM SPEED (AVE. R1 & R2) = N/A (THERE IS NO WB APPROACH) ENTERING SIGHT DISTANCE (NCHRP 672 EQ 6-6) = N/A (THERE IS NO WB APPROACH) CIRCULATING STREAM SPEED (R4) = 17 MPH CIRULATING STREAM DISTANCE (NCHRP 672 EQ 6-7) = 125 FT 125 FT SR NORTHBOUND APPROACH CHECK OF TWO CONFLICTING TRAFFIC STREAMS: ENTERING STREAM SPEED (AVE. R1 & R2) = 21 MPH ENTERING SIGHT DISTANCE (NCHRP 672 EQ 6-6) = 155 FT CIRCULATING STREAM SPEED (R4) = 17 MPH CIRULATING STREAM DISTANCE (NCHRP 672 EQ 6-7) = 125 FT 125 FT 155' SR 655 THORNHILL RD DATE DESCRIPTION REVISIONS DATE DESCRIPTION STATE OF FLORIDA DEPARTMENT OF TRANSPORTATION SR 655 AT THORNHILL RD SHEET NO. ROAD NO. SR 655 COUNTY POLK FINANCIAL PROJECT ID INT. SIGHT DISTANCE 12 Mike.Sasse 8/22/2017 1:33:38 PM C:\Users\mike.sasse\Desktop\ Recker Hwy\roadway\PLANRD08.DGN

15 P 1" = 60' SR 655 N 170 FT 125 FT SR 655 AASHTO 2011 (US) SR EASTBOUND APPROACH CHECK OF TWO CONFLICTING TRAFFIC STREAMS: ENTERING STREAM SPEED (AVE. R1 & R2) = 23 MPH ENTERING SIGHT DISTANCE (NCHRP 672 EQ 6-6) = 170 FT THORNHILL RD CIRCULATING STREAM SPEED (R4) = 17 MPH CIRULATING STREAM DISTANCE (NCHRP 672 EQ 6-7) = 125 FT DATE DESCRIPTION REVISIONS DATE DESCRIPTION STATE OF FLORIDA DEPARTMENT OF TRANSPORTATION ROAD NO. COUNTY FINANCIAL PROJECT ID SR 655 POLK SR 655 AT THORNHILL RD INT. SIGHT DISTANCE SHEET NO. 13 Mike.Sasse 8/22/2017 1:33:38 PM C:\Users\mike.sasse\Desktop\ Recker Hwy\roadway\PLANRD09.DGN

16 APPENDIX A-A Step 1 & Step 2 Roundabout Evaluation

17 101 West Main Street Suite 240 Lakeland, FL Phone Fax Date: January 16, 2017 To: Tyler Wallum, Volkert PM Patrick Bateman, PM FDOT From: Dawn Carlson-RK&K CC: RK&K Daniel Miller, Charles Bleam Re: SR 655 (Recker Highway) Step 2 - Roundabout Evaluation FINAL Introduction The Florida Department of Transportation is conducting an Environmental Impact Report for SR 655 (Recker Highway) in Auburndale, Florida. As part of this assessment in accordance with FDOT policy stated within Section of the Plans Preparation Manual and Design Bulletins (Roadway)/02-15 (Traffic Operations) an analysis was conducted for roundabouts at the following intersections within the project: Thornhill Road (existing traffic signal M.P ) US 92/SR 600 (existing traffic signal M.P ) The initial Step 1 Roundabout Screening was completed in February 2016 (See Appendix A: Roundabout Evaluation Technical Memorandum) to determine if roundabouts are viable at the subject locations. Figure 1 shows the project location. Figure 2 shows the two subject intersections. Results from Step 1 showed that traffic volumes at the US 92/SR 600 intersection exceeded the thresholds for roundabout traffic volumes. Therefore, the US 92 intersection was removed from further study, and a roundabout at Thornhill Road is viable and a Benefit/Cost Analysis (Step 2) should be conducted for the Thornhill Road intersection. The purpose of this memorandum is to document the Step 2 analysis performed for the Recker Highway and Thornhill Road intersection. Step 2 Roundabout Benefit Cost (BC) Analysis for the Recker Highway/Thornhill Road intersection The Step 2 Roundabout BC Evaluation Spreadsheet dated March 2015 from the Florida Department of Transportation was used to compare roundabout costs to an improved traffic signal intersection at Thornhill Road. Figure 3 through Figure 5 show the layouts for Roundabout Alternative A, Roundabout Alternative B, and for an improved traffic signal intersection. With the proposed railroad overpass, Recker Highway will be a four lane highway through the Thornhill intersection becoming a two lane highway southeast of the intersection.

18 Roundabout Alternative A (Alt A) has two circulating lanes and utilizes short lanes for both north and southbound traffic southeast of Thornhill Road to change Recker Highway from two lanes to four lanes southeast of the proposed roundabout at Thornhill. Thornhill Road is a two lane road with an additional exit lane for right turns from southbound Recker Highway. For Roundabout Alternative B (Alt B), the roundabout has essentially one circulating lane with an additional lane for northbound traffic. Recker Highway is two lanes southeast of the roundabout with only the northbound direction having an additional short lane giving Recker Highway two lanes northbound through the roundabout. Southbound Recker highway is two lanes but at the roundabout, the right lane becomes a right turn only lane while only the left lane continues through the roundabout. Thornhill Road is two lanes with no additional exit lane. An improved signalized intersection at Recker Highway and Thornhill Road would have a four lane Recker Highway with an additional left turn lane for northbound traffic turning onto Thornhill Road and an additional right turn lane for southbound traffic turning onto Thornhill Road. Thornhill Road is two lanes with an additional left turn lane for traffic turning north onto Recker Highway. The Step 2 Roundabout BC Evaluation Spreadsheet requires the inputs discussed separately below. Benefit Cost Inputs To compare the benefit/costs of a traditional intersection option versus a roundabout option, costs associated with safety, delay to persons in vehicles, operations and maintenance, and capital construction are incorporated into the spreadsheet for comparison. Operations and Maintenance: The intersection was defined as a three leg Urban and Suburban Arterial with a Suburban area type having an existing traffic signal. For this analysis, Recker Highway has two thru lanes northbound and two thru lanes southbound, a four lane highway, for the proposed railroad overpass. For the traffic signal option, Recker Highway has an additional left turn lane northbound and an additional right turn lane southbound. Thornhill Road has one left turn lane and one right turn lane. Roundabout Alt A has two circulating lanes and Roudnabout Alt B has one circulating lane except for the northbound side of Recker Highway. Lighting is included in all alternatives. There are no red light cameras or right turn on red prohibitions. No schools, bus stops or alcohol sales establishments are within 1000 feet of the intersection. The maximum number of lanes that a pedestrian needs to cross is four. Safety Inputs: The safety inputs used in the analysis include the AADTs for Opening Year (2020) and Design Year (2040) shown in Table 1 below from the previously completed and accepted Project Development and Environment Study, S.R. 655 (Recker Highway) Project Traffic Report, June 2016 (Project Traffic Report). Table 1 Future Traffic Volumes 2020 AADT 2040 AADT Major road - Recker Highway 14,100 20,200 Minor road - Thornhill Road 7,600 11,100 Crash data from the past 6 years (November 1, 2009 through October 31, 2015) was downloaded from Signal Four Analytics crash database. Although the search parameters were from 2009 to 2015, the dates of the crashes at the existing Thornhill Road intersection location are all between September 2010 and October 2015 after the intersection was redesigned. Details of the 20 crashes at the intersection are presented in Table 2. Locations are shown in Figure 6. Pedestrian traffic is minimal at this location so an estimate of 10 pedestrians per day was used in the analysis. Page 2

19 Table 2 Crash Data and Crash Type Summaries Intersection Single Vehicle Multi- Vehicle Property Injury Fatality Pedestrial Bicycle Recker at Thornhill Intersection Rear End Left Turn Backed Into Off Road Sideswipe Rollover Animal Other Recker at Thornhill Capital Cost Inputs: Construction costs for completing the different roundabout alternatives and signalized intersection alternative were obtained from FDOT in the form of LREs and are attached in Appendix B. Estimated rightof-way costs for both roundabout alternatives were also obtained from FDOT and are listed in Appendix C. Right-of-way costs for the traffic signal intersection were estimated using the average ratio (0.828) of the ratio of Right-of-way costs to Construction costs for the roundabouts and applying that ratio to the traffic signal construction costs to estimate the traffic signal ROW cost. Preliminary engineering costs were estimated from previous roundabout construction projects completed in Polk County. All cost values are shown in Table 3. Table 3 Capital Costs Costs Signal Roundabout A Roundabout B Comments Prelim. Engineering $98,905 $220,000 $220,000 Right-of-way $428,238 $874,000 $886,000 Construction $659,368 $1,061,943 $1,061,943 From LREs TOTAL $1,186,511 $2,155,943 $2,167,943 Delay Inputs: Delays for the roundabout were calculated using SIDRA Intersection 6.1 Plus software with the District 1 standard roundabout inputs and the 2020 and 2040 Build AM and PM Directional Design Hour Volumes (DDHV) from the Project Traffic Report. Traditional signal intersection delays were taken from the Synchro outputs used in the Project Traffic Report. Delay results are shown in Table 4. SIDRA outputs for the roundabout alternatives are in Appendix D and Synchro outputs from the PTR are provided in Appendix E. Table 4 Intersection Delays and Hourly Traffic Entering Intersection Delay in seconds Hourly Traffic Entering Intersection Recker Hwy at Thornhill Rd AM PM AM PM AM PM AM PM Roundabout Alt A Roundabout Alt B Signal Page 3

20 Benefit Cost Results The benefit to cost ratio for roundabout Alt 1 and Alt 2 are 4.3 and 4.4 respectively showing that a roundabout is a higher benefit (in terms of safety) than a signalized intersection at the Recker Highway / Thornhill Road intersection. The Benefit Cost results and Life Cycle Costs for each alternative are shown in Appendix F. Our recommendation is to continue with roundabout design and the Step 3 Roundabout Summary Report shown in Figure 7. Page 4

21 Figure 1 Project Location Page 5

22 Figure 2 Intersection Locations Page 6

23 Figure 3 Roundabout Alternative A Page 7

24 Figure 4 Roundabout Alternative B Page 8

25 Figure 5 Traffic Signal Alternative Page 9

26 Figure 6 Signal Four Analytics Crash Locations 20 Crashes Reported at this Intersection from Nov. 1, 2009 to Oct. 31, HSMV Report #s Exported data from Signal Four Analytics detailing these crashes is provided as a separate file accompanying this report. Page 10

27 Figure 7 Step 3 Roundabout Summary Report Page 11

28 APPENDIX A Roundabout Evaluation Technical Memorandum (Step 1) Page 12

29 101 West Main Street Suite 240 Lakeland, FL Phone Fax Date: February 19, 2016, Revised March 3, 2016 To: Tony Sherrard PM FDOT Patrick Bateman Nicole Harris, Volkert PM From: OJ (Richard) Oujevolk-RK&K CC: RK&K Daniel Miller, Charles Bleam Re: SR 655 (Recker Highway) Roundabout Evaluation Introduction The Florida Department of Transportation is conducting an Environmental Impact Report for SR 655 (Recker Highway) in Auburndale, Florida. As part of this assessment in accordance with FDOT policy stated within Section of the Plans Preparation Manual and Design Bulletins (Roadway)/02-15 (Traffic Operations) an analysis was conducted for the following intersections within the project: Thornhill Road (existing traffic signal M.P ) US 92/SR 600 (existing traffic signal M.P ) Other non-signalized intersections were not considered since the proposed improvement is a bridge overpass of the CSX railroad located at M.P and would change access for the local cross streets via service roads. Figure 1-1 shows the project location. Figure 1-2 provides a reduced version of the RCI map for SR 655 and an enlargement of the two subject intersections. Two Alternatives (1 and 2) where considered. Although very similar, the primary differences between Alternative 1 and 2 are the curb returns for the SR 655 connection to Thornhill Road. If a roundabout is chosen for this location, the roundabout design geometry will have an impact to these curb return radii. Alternative 2 is the configuration preferred with the roundabout if it advances to step 2. The initial step in the process (Step 1) is to determine if a roundabout is viable for the subject locations. Roundabout Analysis As cited within Design Bulletin 15-07,

30 Under this initial criteria, the intersection of US 92/SR 600 can be dropped from further analysis as the total entering volume at this location is 56,900 vehicles per day in the 2040 design year for the project. The SR 655/Thornhill Road intersection is under this threshold (2040 design year volume is 21,850 vpd) and will be further analyzed using the Step 1 criteria. Estimated year 2040 volumes are shown in Figure 1-3. Step 1 Roundabout Screening The Roundabout Form Step 1 Roundabout Screening was completed for the intersection. The evaluation criteria consists of six screening criteria that preclude proceeding to Step 2. The analysis is provided at the end of this report for either approval or denial by the District Design or Traffic Operations Engineer. Based on the 6 criteria cited in Step 1, Criteria 5 and 6 need further consideration. Criteria 5: Is there a downstream traffic control device that could cause queues to back up into the intersection? Yes. Under current conditions traffic may back up from the intersection of SR 655 and US 92/SR 600. Queuing analysis for that signalized intersection indicates 95 percentile queues require 275 feet plus deceleration taper. This distance will not impact the intersection but the possibility exists that under extreme conditions it may occur. Criteria 6: Would the installation of a roundabout create impacts to historical, 4(f), or environmentally sensitive sites? Yes. Would the relocation of residences or businesses be required? No. There is a cemetery (Auburndale Memorial Park) is directly opposite of the proposed roundabout but no impacts are anticipated. In addition, two businesses may have minor impacts but no relocations are anticipated. Preliminary roundabout layouts (just inscribed circles) where drawn at this location and should avoidance of the Cemetery and minor impacts to adjacent property owners. See Figures 1-4 and 1-5. Although, Criteria 5 and 6 are answered Yes, project information indicates Criteria 5 (queuing) will not impact the proposed roundabout location however, 95 th percentile queues do not indicate an impact. Criteria 6 (environmental impacts/residential and business impacts) indicate only minor impacts. It is recommended that the SR 655 at Thornhill Road intersection move forward to Step 2 (Benefit/Cost) and the concept be refined to determine if roundabout is feasible at this location.

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32 Figure 1-2 Roundabout Analysis Locations N NTS SR SR 600 (US 92) Existing Traffic Signal M.P Road ID Step 1 Analysis Not Recommended Approved by District Design/Traffic Operations Eng. Yes: No: SR Thornhill Road Existing Traffic Signal M.P Road ID Step 1 Analysis Recommended Approved by District Design/Traffic Operations Eng. Yes: No: Existing Traffic Signal

33 Figure 1-3 Design Year 2040 AADT

34 Figure 1-4 Preliminary Roundabout Concept 1

35 Figure 1-5 Preliminary Roundabout Concept 1

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37 APPENDIX B LRE for Roundabout LRE for Signal Page 13

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39

40

41

42 Cost Estimates for Traffic Signal Pages from

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44

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46 APPENDIX C Right-of-Way Cost Estimates for Roundabout Alternatives Page 14

47 CONCEPTUAL ESTIMATE, ALTERNATES / SEGMENTS: PHASE COSTS SUMMARY The basis for this estimate is "cost" not market value ** EXEMPT FROM PUBLIC DISCLOSURE - FS: ** ITEM SEG: , COUNTY: POLK, LIMITS: COST ESTIMATE NUMBER: FOR: BY: Alternate / Segment: Tony Sherrard WS Sullivan DATE: Alternatives one and two SR 655 from Bridge Spanning CSX RR Track 6/27/2016 Description: Size Sq.Ft: Parcels Relo.Cnt Phase: 4B Phase: 41 Phase: 42 Phase: 43 Phase: 45 Total: Altternative 1 123, $78,000 $36,000 $0 $760,000 $0 $874,000 Altternative 2 126, $78,000 $36,000 $0 $772,000 $0 $886,000 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 Total All Sheets: 250, $156,000 $72,000 $0 $1,532,000 $0 $1,760,000 #N/A

48 APPENDIX D SIDRA Delay Outputs for Roundabouts Alternative A 2020 AM 2020 PM 2040 AM 2040 PM Alternative B 2020 AM 2020 PM 2040 AM 2040 PM Synchro/HCS Delay Outputs for Traffic Signal Alternative Page 15

49 DELAY (CONTROL) Average control delay per vehicle, or average pedestrian delay (seconds) Site: Recker at Thornhill Alt 2A 2020 AM Roundabout Roundabout All Movement Classes South North West Intersection LOS A A B A Colour code based on Level of Service LOS A LOS B LOS C LOS D LOS E LOS F Continuous Level of Service Method: Delay & v/c (HCM 2010) LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Roundabout Level of Service Method: Same as Sign Control SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :03:26 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\Sidra Files\with 10 percent trucks\roundabout Alt 2A at Recker and

50 Thornhill 2020 AM Revised sip6

51 DELAY (CONTROL) Average control delay per vehicle, or average pedestrian delay (seconds) Site: Recker at Thornhill Alt 2A 2020 PM Roundabout Roundabout All Movement Classes South North West Intersection LOS A A B A Colour code based on Level of Service LOS A LOS B LOS C LOS D LOS E LOS F Continuous Level of Service Method: Delay & v/c (HCM 2010) LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Roundabout Level of Service Method: Same as Sign Control SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :05:01 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\SidraFiles\with 10 percent trucks\roundabout Alt 2A atrecker and

52 Thornhill 2020 PM Revised sip6

53 DELAY (CONTROL) Average control delay per vehicle, or average pedestrian delay (seconds) Site: Recker at Thornhill 2040 AM Roundabout Roundabout All Movement Classes South North West Intersection LOS A A C A Colour code based on Level of Service LOS A LOS B LOS C LOS D LOS E LOS F Continuous Level of Service Method: Delay & v/c (HCM 2010) LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Roundabout Level of Service Method: Same as Sign Control SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :07:36 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\Sidra Files\with 10 percent trucks\roundabout Alt 2A at Recker and

54 Thornhill 2040 AM revised sip6

55 DELAY (CONTROL) Average control delay per vehicle, or average pedestrian delay (seconds) Site: Recker at Thornhill 2040 PM Roundabout Roundabout All Movement Classes South North West Intersection LOS A A C B Colour code based on Level of Service LOS A LOS B LOS C LOS D LOS E LOS F Continuous Level of Service Method: Delay & v/c (HCM 2010) LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Roundabout Level of Service Method: Same as Sign Control SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :09:19 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\Sidra Files\with 10 percent trucks\roundabout Alt 2A at Recker and

56 Thornhill 2040 PM Revised sip6

57 DELAY (CONTROL) Average control delay per vehicle, or average pedestrian delay (seconds) Site: Recker at Thornhill Alt 2B 2020 AM Roundabout Roundabout All Movement Classes South North West Intersection LOS A A B A Colour code based on Level of Service LOS A LOS B LOS C LOS D LOS E LOS F Continuous Level of Service Method: Delay & v/c (HCM 2010) LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Roundabout Level of Service Method: Same as Sign Control SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :16:51 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\Sidra Files\with 11.5 percent trucks\roundabout Alt 2B at Recker

58 and Thornhill 2020 AM Revised sip6

59 DELAY (CONTROL) Average control delay per vehicle, or average pedestrian delay (seconds) Site: Recker at Thornhill Alt 2B 2020 PM Roundabout Roundabout All Movement Classes South North West Intersection LOS A A B A Colour code based on Level of Service LOS A LOS B LOS C LOS D LOS E LOS F Continuous Level of Service Method: Delay & v/c (HCM 2010) LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Roundabout Level of Service Method: Same as Sign Control SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :20:01 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\Sidra Files\with 11.5 percent trucks\roundabout Alt 2B at Recker

60 and Thornhill 2020 PM Revised sip6

61 DELAY (CONTROL) Average control delay per vehicle, or average pedestrian delay (seconds) Site: Recker at Thornhill Alt 2B 2040 AM Roundabout Roundabout All Movement Classes South North West Intersection LOS A A C A Colour code based on Level of Service LOS A LOS B LOS C LOS D LOS E LOS F Continuous Level of Service Method: Delay & v/c (HCM 2010) LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Roundabout Level of Service Method: Same as Sign Control SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :22:30 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\SidraFiles\with 11.5 percent trucks\roundabout Alt 2B at Recker

62 and Thornhill 2040 AM revised sip6

63 DELAY (CONTROL) Average control delay per vehicle, or average pedestrian delay (seconds) Site: Recker at Thornhill Alt 2B 2040 PM Roundabout Roundabout All Movement Classes South North West Intersection LOS A A C A Colour code based on Level of Service LOS A LOS B LOS C LOS D LOS E LOS F Continuous Level of Service Method: Delay & v/c (HCM 2010) LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Roundabout Level of Service Method: Same as Sign Control SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :23:51 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\Sidra Files\with 11.5 percent trucks\roundabout Alt 2B at Recker

64 and Thornhill 2040 PM Revised sip6

65 Lanes, Volumes, Timings 9: Recker Hwy & Thornhill Rd. SignalTimed AM - BuildOverpass.syn 6/16/2016 Lane Group EBL EBR NBL NBT SBT SBR Lane Configurations Traffic Volume (vph) Future Volume (vph) Ideal Flow (vphpl) Storage Length (ft) Storage Lanes Taper Length (ft) Satd. Flow (prot) Flt Permitted Satd. Flow (perm) Right Turn on Red Yes Yes Satd. Flow (RTOR) Link Speed (mph) Link Distance (ft) Travel Time (s) Peak Hour Factor Adj. Flow (vph) Shared Lane Traffic (%) Lane Group Flow (vph) Turn Type Prot Perm Perm NA NA Perm Protected Phases Permitted Phases Total Split (s) Total Lost Time (s) Act Effct Green (s) Actuated g/c Ratio v/c Ratio Control Delay Queue Delay Total Delay LOS C A B B B A Approach Delay Approach LOS C B B Queue Length 50th (ft) Queue Length 95th (ft) Internal Link Dist (ft) Turn Bay Length (ft) Base Capacity (vph) Starvation Cap Reductn Spillback Cap Reductn Storage Cap Reductn Reduced v/c Ratio Intersection Summary Area Type: Other Cycle Length: 110 Actuated Cycle Length: 110 Offset: 0 (0%), Referenced to phase 2:SBT and 6:NBTL, Start of Green Control Type: Pretimed Baseline Synchro 9 Report Page 3

66 Lanes, Volumes, Timings 9: Recker Hwy & Thornhill Rd. SignalTimed AM - BuildOverpass.syn 6/16/2016 Maximum v/c Ratio: 0.42 Intersection Signal Delay: 15.1 Intersection Capacity Utilization 50.7% Analysis Period (min) 15 Intersection LOS: B ICU Level of Service A Splits and Phases: 9: Recker Hwy & Thornhill Rd. Baseline Synchro 9 Report Page 4

67 Lanes, Volumes, Timings 9: Recker Hwy & Thornhill Rd. SignalTimed PM - BuildOverpass.syn 6/16/2016 Lane Group EBL EBR NBL NBT SBT SBR Lane Configurations Traffic Volume (vph) Future Volume (vph) Ideal Flow (vphpl) Storage Length (ft) Storage Lanes Taper Length (ft) Satd. Flow (prot) Flt Permitted Satd. Flow (perm) Right Turn on Red Yes Yes Satd. Flow (RTOR) Link Speed (mph) Link Distance (ft) Travel Time (s) Peak Hour Factor Adj. Flow (vph) Shared Lane Traffic (%) Lane Group Flow (vph) Turn Type Prot Perm Perm NA NA Perm Protected Phases Permitted Phases Total Split (s) Total Lost Time (s) Act Effct Green (s) Actuated g/c Ratio v/c Ratio Control Delay Queue Delay Total Delay LOS C A B B B A Approach Delay Approach LOS C B B Queue Length 50th (ft) Queue Length 95th (ft) Internal Link Dist (ft) Turn Bay Length (ft) Base Capacity (vph) Starvation Cap Reductn Spillback Cap Reductn Storage Cap Reductn Reduced v/c Ratio Intersection Summary Area Type: Other Cycle Length: 110 Actuated Cycle Length: 110 Offset: 0 (0%), Referenced to phase 2:SBT and 6:NBTL, Start of Green Control Type: Pretimed Baseline Synchro 9 Report Page 3

68 Lanes, Volumes, Timings 9: Recker Hwy & Thornhill Rd. SignalTimed PM - BuildOverpass.syn 6/16/2016 Maximum v/c Ratio: 0.53 Intersection Signal Delay: 16.9 Intersection Capacity Utilization 52.5% Analysis Period (min) 15 Intersection LOS: B ICU Level of Service A Splits and Phases: 9: Recker Hwy & Thornhill Rd. Baseline Synchro 9 Report Page 4

69 Lanes, Volumes, Timings 9: Recker Hwy & Thornhill Rd. SignalTimed AM - BuildOverpass.syn 6/16/2016 Lane Group EBL EBR NBL NBT SBT SBR Lane Configurations Traffic Volume (vph) Future Volume (vph) Ideal Flow (vphpl) Storage Length (ft) Storage Lanes Taper Length (ft) Satd. Flow (prot) Flt Permitted Satd. Flow (perm) Right Turn on Red Yes Yes Satd. Flow (RTOR) Link Speed (mph) Link Distance (ft) Travel Time (s) Peak Hour Factor Adj. Flow (vph) Shared Lane Traffic (%) Lane Group Flow (vph) Turn Type Prot Perm Perm NA NA Perm Protected Phases Permitted Phases Total Split (s) Total Lost Time (s) Act Effct Green (s) Actuated g/c Ratio v/c Ratio Control Delay Queue Delay Total Delay LOS C A B B B A Approach Delay Approach LOS C B B Queue Length 50th (ft) Queue Length 95th (ft) Internal Link Dist (ft) Turn Bay Length (ft) Base Capacity (vph) Starvation Cap Reductn Spillback Cap Reductn Storage Cap Reductn Reduced v/c Ratio Intersection Summary Area Type: Other Cycle Length: 110 Actuated Cycle Length: 110 Offset: 0 (0%), Referenced to phase 2:SBT and 6:NBTL, Start of Green Control Type: Pretimed Baseline Synchro 9 Report Page 3

70 Lanes, Volumes, Timings 9: Recker Hwy & Thornhill Rd. SignalTimed AM - BuildOverpass.syn 6/16/2016 Maximum v/c Ratio: 0.50 Intersection Signal Delay: 15.7 Intersection Capacity Utilization 55.7% Analysis Period (min) 15 Intersection LOS: B ICU Level of Service B Splits and Phases: 9: Recker Hwy & Thornhill Rd. Baseline Synchro 9 Report Page 4

71 Lanes, Volumes, Timings 9: Recker Hwy & Thornhill Rd. SignalTimed PM - BuildOverpass.syn 6/16/2016 Lane Group EBL EBR NBL NBT SBT SBR Lane Configurations Traffic Volume (vph) Future Volume (vph) Ideal Flow (vphpl) Storage Length (ft) Storage Lanes Taper Length (ft) Satd. Flow (prot) Flt Permitted Satd. Flow (perm) Right Turn on Red Yes Yes Satd. Flow (RTOR) Link Speed (mph) Link Distance (ft) Travel Time (s) Peak Hour Factor Adj. Flow (vph) Shared Lane Traffic (%) Lane Group Flow (vph) Turn Type Prot Perm Perm NA NA Perm Protected Phases Permitted Phases Total Split (s) Total Lost Time (s) Act Effct Green (s) Actuated g/c Ratio v/c Ratio Control Delay Queue Delay Total Delay LOS C A B B B A Approach Delay Approach LOS C B B Queue Length 50th (ft) Queue Length 95th (ft) Internal Link Dist (ft) Turn Bay Length (ft) Base Capacity (vph) Starvation Cap Reductn Spillback Cap Reductn Storage Cap Reductn Reduced v/c Ratio Intersection Summary Area Type: Other Cycle Length: 110 Actuated Cycle Length: 110 Offset: 0 (0%), Referenced to phase 2:SBT and 6:NBTL, Start of Green Control Type: Pretimed Baseline Synchro 9 Report Page 3

72 Lanes, Volumes, Timings 9: Recker Hwy & Thornhill Rd. SignalTimed PM - BuildOverpass.syn 6/16/2016 Maximum v/c Ratio: 0.63 Intersection Signal Delay: 17.8 Intersection Capacity Utilization 57.9% Analysis Period (min) 15 Intersection LOS: B ICU Level of Service B Splits and Phases: 9: Recker Hwy & Thornhill Rd. Baseline Synchro 9 Report Page 4

73 Lanes, Volumes, Timings 9: Recker Hwy & Thornhill Rd. SignalTimed AM - BuildOverpass.syn 6/16/2016 Lane Group EBL EBR NBL NBT SBT SBR Lane Configurations Traffic Volume (vph) Future Volume (vph) Ideal Flow (vphpl) Storage Length (ft) Storage Lanes Taper Length (ft) Satd. Flow (prot) Flt Permitted Satd. Flow (perm) Right Turn on Red Yes Yes Satd. Flow (RTOR) Link Speed (mph) Link Distance (ft) Travel Time (s) Peak Hour Factor Adj. Flow (vph) Shared Lane Traffic (%) Lane Group Flow (vph) Turn Type Prot Perm Perm NA NA Perm Protected Phases Permitted Phases Total Split (s) Total Lost Time (s) Act Effct Green (s) Actuated g/c Ratio v/c Ratio Control Delay Queue Delay Total Delay LOS C A B B B A Approach Delay Approach LOS C B B Queue Length 50th (ft) Queue Length 95th (ft) Internal Link Dist (ft) Turn Bay Length (ft) Base Capacity (vph) Starvation Cap Reductn Spillback Cap Reductn Storage Cap Reductn Reduced v/c Ratio Intersection Summary Area Type: Other Cycle Length: 110 Actuated Cycle Length: 110 Offset: 0 (0%), Referenced to phase 2:SBT and 6:NBTL, Start of Green Control Type: Pretimed Baseline Synchro 9 Report Page 3

74 Lanes, Volumes, Timings 9: Recker Hwy & Thornhill Rd. SignalTimed AM - BuildOverpass.syn 6/16/2016 Maximum v/c Ratio: 0.59 Intersection Signal Delay: 16.4 Intersection Capacity Utilization 61.2% Analysis Period (min) 15 Intersection LOS: B ICU Level of Service B Splits and Phases: 9: Recker Hwy & Thornhill Rd. Baseline Synchro 9 Report Page 4

75 Lanes, Volumes, Timings 9: Recker Hwy & Thornhill Rd. SignalTimed PM - BuildOverpass.syn 6/16/2016 Lane Group EBL EBR NBL NBT SBT SBR Lane Configurations Traffic Volume (vph) Future Volume (vph) Ideal Flow (vphpl) Storage Length (ft) Storage Lanes Taper Length (ft) Satd. Flow (prot) Flt Permitted Satd. Flow (perm) Right Turn on Red Yes Yes Satd. Flow (RTOR) Link Speed (mph) Link Distance (ft) Travel Time (s) Peak Hour Factor Adj. Flow (vph) Shared Lane Traffic (%) Lane Group Flow (vph) Turn Type Prot Perm Perm NA NA Perm Protected Phases Permitted Phases Total Split (s) Total Lost Time (s) Act Effct Green (s) Actuated g/c Ratio v/c Ratio Control Delay Queue Delay Total Delay LOS D A B B B A Approach Delay Approach LOS C B B Queue Length 50th (ft) Queue Length 95th (ft) Internal Link Dist (ft) Turn Bay Length (ft) Base Capacity (vph) Starvation Cap Reductn Spillback Cap Reductn Storage Cap Reductn Reduced v/c Ratio Intersection Summary Area Type: Other Cycle Length: 110 Actuated Cycle Length: 110 Offset: 0 (0%), Referenced to phase 2:SBT and 6:NBTL, Start of Green Control Type: Pretimed Baseline Synchro 9 Report Page 3

76 Lanes, Volumes, Timings 9: Recker Hwy & Thornhill Rd. SignalTimed PM - BuildOverpass.syn 6/16/2016 Maximum v/c Ratio: 0.74 Intersection Signal Delay: 19.1 Intersection Capacity Utilization 63.6% Analysis Period (min) 15 Intersection LOS: B ICU Level of Service B Splits and Phases: 9: Recker Hwy & Thornhill Rd. Baseline Synchro 9 Report Page 4

77 APPENDIX E Benefit Costs Evaluation Life Cycle Costs and Results for Roundabout Alternatives A and B Page 16

78 FDOT Level 2 Roundabout b/c Evaluation Annual Costs Roundabout Traffic Signal Safety Predicted Annual Crashes Safety Cost Predicted Annual Crashes Safety Cost Predicted Fatal/Injury Crashes 0.24 $ 88, $ 305,398 Predicted PDO Crashes 1.76 $ 13, $ 12,432 Annual Costs of Predicted Crashes $ 101,956 Annual Costs of Predicted Crashes $ 317,830 Delay Annual Intersection Delay (person-hrs) Delay Cost Annual Intersection Delay (person-hrs) Delay Cost Average Annual Person (in Vehicle) Delay 3341 $ 40, $ 80,664 Operation and Maintenance Operation and Maintenance O&M Cost Operation and Maintenance O&M Cost Annualized Cost of Signal Retiming $ - Signal Retiming Every 3 Years $ 1,667 Annual Cost of Illumination Intersection Illumination $ 750 Intersection Illumination $ 750 Annual Cost of Maintenance Landscaping Costs $ 2,000 Signal Maintenance Costs (power outage, detection, etc.) $ 3,100 Total Annual Operation and Maintenance Costs $ 2,750 Total Annual Operation and Maintenance Costs $ 5,517 Initial Capital Costs Total Capital Costs Cost Total Capital Costs Cost Preliminary Engineering $ 220,000 $ 98,905 Right-of-way and Utilities $ 886,000 $ 428,238 Construction $ 1,061,943 $ 659,368 *Delay cost is based upon a 2 hour analysis period. Total Discounted Life Cycle Costs ( ) Roundabout Traffic Signal Safety Total Predicted Crashes Safety Cost Total Predicted Crashes Safety Cost Predicted Fatal/Injury Crashes 4.87 $ 1,317, $ 4,543,556 Predicted PDO Crashes $ 199, $ 184,958 Total Costs of Predicted Crashes $ 1,516,849 Total Costs of Predicted Crashes $ 4,728,513 Delay Total Intersection Delay (person-hrs) Delay Cost Total Intersection Delay (person-hrs) Delay Cost Total Person (in Vehicle) Delay $ 856, $ 1,693,951 Operation and Maintenance Operation and Maintenance O&M Cost Operation and Maintenance O&M Cost Annualized Cost of Signal Retiming $ - Signal Retiming Every 3 Years $ 24,796 Annual Cost of Illumination Intersection Illumination $ 11,158 Intersection Illumination $ 11,158 Annual Cost of Maintenance Landscaping Costs $ 29,755 Signal Maintenance Costs (power outage, detection, etc.) $ 46,120 Total Annual Operation and Maintenance Costs $ 40,913 Total Annual Operation and Maintenance Costs $ 82,074 Initial Capital Costs Total Capital Costs Cost Total Capital Costs Cost Preliminary Engineering $ 220,000 $ 98,905 Right-of-way and Utilities $ 886,000 $ 428,238 Construction $ 1,061,943 $ 659,368 Total Initial Capital Costs $ 2,167,943 Total Initial Capital Costs $ 1,186,512 Total Life Cycle Costs (Opening Year $) Net Present Value $ 4,582,495 Net Present Value $ 7,691,050 *Delay cost is based upon a 2 hour analysis period. Roundabout Traffic Signal Life Cycle Benefit/Cost Ratio Safety Benefit of a Roundabout $ 3,211,664 Delay Reduction Benefit of a Roundabout $ 837,161 Total Benefits $ 4,048,825 Added Operations&Maintenance Costs of a Roundabout $ (41,161) Added Capital Costs of a Roundabout $ 981,431 Total Costs $ 940,270 Life Cycle Benefit/Cost Ratio 4.3 Roundabout Compared to Traffic Signal Roundabout Preferred

79 FLORIDA DEPARTMENT OF TRANSPORTATION STEP 2 -b/c EVALUATION Prepared by: Financial Project ID: FAP No.: County: Daniel R. Miller, P.E Polk Date Prepared: Project Name: State Road: Intersecting Rd: 1/6/2017 Recker Highway 655 Thornhill Road ANNUAL COSTS Roundabout Traffic Signal Safety Cost (Crashes) $ 101,956 $ 317,830 Delay Cost $ 40,800 $ 80,664 O & M Cost $ 2,750 $ 5,517 Initial Capital Cost Preliminary Engineering $ 220,000 $ 98,905 Right-of-way and Utilities $ 886,000 $ 428,238 Construction $ 1,061,943 $ 659,368 TOTAL DISCOUNTED LIFE CYCLE COSTS (OPENING YEAR) Roundabout Traffic Signal Safety Cost (Crashes) $ 1,516,849 $ 4,728,513 Delay Cost $ 856,790 $ 1,693,951 O & M Cost $ 40,913 $ 82,074 Initial Capital Cost $ 2,167,943 $ 1,186,512 Total Life Cycle Costs $ 4,582,495 $ 7,691,050 LIFECYCLE BENEFIT/COST RATIO Safety Benefit of a Roundabout $ 3,211,664 Delay Reduction Benefit of a Roundabout $ 837,161 Total Benefit $ 4,048,825 Added O & M Costs of a Rondabout $ (41,161) Added Capital Costs of a Roundabout $ 981,431 Total Cost $ 940,270 Life Cycle Benefit/Cost Ratio 4.3 Advance to Level 3 Geometric and Operational Analysis: YES NO Approved by: DDE or DTOE Signature: Date:

80 FDOT Level 2 Roundabout b/c Evaluation Annual Costs Roundabout Traffic Signal Safety Predicted Annual Crashes Safety Cost Predicted Annual Crashes Safety Cost Predicted Fatal/Injury Crashes 0.24 $ 88, $ 305,398 Predicted PDO Crashes 1.76 $ 13, $ 12,432 Annual Costs of Predicted Crashes $ 101,956 Annual Costs of Predicted Crashes $ 317,830 Delay Annual Intersection Delay (person-hrs) Delay Cost Annual Intersection Delay (person-hrs) Delay Cost Average Annual Person (in Vehicle) Delay 3136 $ 38, $ 80,664 Operation and Maintenance Operation and Maintenance O&M Cost Operation and Maintenance O&M Cost Annualized Cost of Signal Retiming $ - Signal Retiming Every 3 Years $ 1,667 Annual Cost of Illumination Intersection Illumination $ 750 Intersection Illumination $ 750 Annual Cost of Maintenance Landscaping Costs $ 2,000 Signal Maintenance Costs (power outage, detection, etc.) $ 3,100 Total Annual Operation and Maintenance Costs $ 2,750 Total Annual Operation and Maintenance Costs $ 5,517 Initial Capital Costs Total Capital Costs Cost Total Capital Costs Cost Preliminary Engineering $ 220,000 $ 98,905 Right-of-way and Utilities $ 886,000 $ 428,238 Construction $ 1,061,943 $ 659,368 *Delay cost is based upon a 2 hour analysis period. Total Discounted Life Cycle Costs ( ) Roundabout Traffic Signal Safety Total Predicted Crashes Safety Cost Total Predicted Crashes Safety Cost Predicted Fatal/Injury Crashes 4.87 $ 1,317, $ 4,543,556 Predicted PDO Crashes $ 199, $ 184,958 Total Costs of Predicted Crashes $ 1,516,849 Total Costs of Predicted Crashes $ 4,728,513 Delay Total Intersection Delay (person-hrs) Delay Cost Total Intersection Delay (person-hrs) Delay Cost Total Person (in Vehicle) Delay $ 806, $ 1,693,951 Operation and Maintenance Operation and Maintenance O&M Cost Operation and Maintenance O&M Cost Annualized Cost of Signal Retiming $ - Signal Retiming Every 3 Years $ 24,796 Annual Cost of Illumination Intersection Illumination $ 11,158 Intersection Illumination $ 11,158 Annual Cost of Maintenance Landscaping Costs $ 29,755 Signal Maintenance Costs (power outage, detection, etc.) $ 46,120 Total Annual Operation and Maintenance Costs $ 40,913 Total Annual Operation and Maintenance Costs $ 82,074 Initial Capital Costs Total Capital Costs Cost Total Capital Costs Cost Preliminary Engineering $ 220,000 $ 98,905 Right-of-way and Utilities $ 886,000 $ 428,238 Construction $ 1,061,943 $ 659,368 Total Initial Capital Costs $ 2,167,943 Total Initial Capital Costs $ 1,186,512 Total Life Cycle Costs (Opening Year $) Net Present Value $ 4,532,364 Net Present Value $ 7,691,050 *Delay cost is based upon a 2 hour analysis period. Roundabout Traffic Signal Life Cycle Benefit/Cost Ratio Safety Benefit of a Roundabout $ 3,211,664 Delay Reduction Benefit of a Roundabout $ 887,292 Total Benefits $ 4,098,956 Added Operations&Maintenance Costs of a Roundabout $ (41,161) Added Capital Costs of a Roundabout $ 981,431 Total Costs $ 940,270 Life Cycle Benefit/Cost Ratio 4.4 Roundabout Compared to Traffic Signal Roundabout Preferred

81 FLORIDA DEPARTMENT OF TRANSPORTATION STEP 2 -b/c EVALUATION Prepared by: Financial Project ID: FAP No.: County: Daniel R. Miller, P.E Polk Date Prepared: Project Name: State Road: Intersecting Rd: 1/6/2017 Recker Highway 655 Thornhill Road ANNUAL COSTS Roundabout Traffic Signal Safety Cost (Crashes) $ 101,956 $ 317,830 Delay Cost $ 38,412 $ 80,664 O & M Cost $ 2,750 $ 5,517 Initial Capital Cost Preliminary Engineering $ 220,000 $ 98,905 Right-of-way and Utilities $ 886,000 $ 428,238 Construction $ 1,061,943 $ 659,368 TOTAL DISCOUNTED LIFE CYCLE COSTS (OPENING YEAR) Roundabout Traffic Signal Safety Cost (Crashes) $ 1,516,849 $ 4,728,513 Delay Cost $ 806,659 $ 1,693,951 O & M Cost $ 40,913 $ 82,074 Initial Capital Cost $ 2,167,943 $ 1,186,512 Total Life Cycle Costs $ 4,532,364 $ 7,691,050 LIFECYCLE BENEFIT/COST RATIO Safety Benefit of a Roundabout $ 3,211,664 Delay Reduction Benefit of a Roundabout $ 887,292 Total Benefit $ 4,098,956 Added O & M Costs of a Rondabout $ (41,161) Added Capital Costs of a Roundabout $ 981,431 Total Cost $ 940,270 Life Cycle Benefit/Cost Ratio 4.4 Advance to Level 3 Geometric and Operational Analysis: YES NO Approved by: DDE or DTOE Signature: Date:

82 APPENDIX B-B Roundabout Movement Summary

83 MOVEMENT SUMMARY Site:Recker at Thornhill Alt A 2020 AM Roundabout Roundabout Movement Performance - Vehicles Mov OD Demand Flows Deg. Average Level of 95% Back of Queue Prop. Effective Average ID Mov Total HV Satn Delay Service Vehicles Distance Queued Stop Rate Speed veh/h % v/c sec veh ft per veh mph South: Recker Hwy 3 L LOS B T LOS A Approach LOS A North: Recker Hwy 4 T LOS A R LOS A Approach LOS A West: Thornhill Road 5 L LOS B R LOS A Approach LOS B All Vehicles LOS A Level of Service (LOS) Method: Delay & v/c (HCM 2010). Roundabout LOS Method: Same as Sign Control. Vehicle movement LOS values are based on average delay and v/c ratio (degree of saturation) per movement LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Intersection and Approach LOS values are based on average delay for all movements (v/c not used as specified in HCM 2010). Roundabout Capacity Model: SIDRA Standard. SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. Gap-Acceptance Capacity: SIDRA Standard (Akçelik M3D). HV (%) values are calculated for All Movement Classes of All Heavy Vehicle Model Designation. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :03:26 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\SidraFiles\with 11.5 percent trucks\roundabout Alt 2A at Recker and Thornhill 2020 AM Revised sip6

84 MOVEMENT SUMMARY Site:Recker at Thornhill Alt A 2020 PM Roundabout Roundabout Movement Performance - Vehicles Mov OD Demand Flows Deg. Average Level of 95% Back of Queue Prop. Effective Average ID Mov Total HV Satn Delay Service Vehicles Distance Queued Stop Rate Speed veh/h % v/c sec veh ft per veh mph South: Recker Hwy 3 L LOS B T LOS A Approach LOS A North: Recker Hwy 4 T LOS A R LOS A Approach LOS A West: Thornhill Road 5 L LOS B R LOS A Approach LOS B All Vehicles LOS A Level of Service (LOS) Method: Delay & v/c (HCM 2010). Roundabout LOS Method: Same as Sign Control. Vehicle movement LOS values are based on average delay and v/c ratio (degree of saturation) per movement LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Intersection and Approach LOS values are based on average delay for all movements (v/c not used as specified in HCM 2010). Roundabout Capacity Model: SIDRA Standard. SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. Gap-Acceptance Capacity: SIDRA Standard (Akçelik M3D). HV (%) values are calculated for All Movement Classes of All Heavy Vehicle Model Designation. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :05:01 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\SidraFiles\with 11.5 percent trucks\roundabout Alt 2A at Recker and Thornhill 2020 PM Revised sip6

85 MOVEMENT SUMMARY Site: Recker at Thornhill Alt A 2040 AM Roundabout Roundabout Movement Performance - Vehicles Mov OD Demand Flows Deg. Average Level of 95% Back of Queue Prop. Effective Average ID Mov Total HV Satn Delay Service Vehicles Distance Queued Stop Rate Speed veh/h % v/c sec veh ft per veh mph South: Recker Hwy 3 L LOS B T LOS A Approach LOS A North: Recker Hwy 4 T LOS A R LOS A Approach LOS A West: Thornhill Road 5 L LOS C R LOS C Approach LOS C All Vehicles LOS A Level of Service (LOS) Method: Delay & v/c (HCM 2010). Roundabout LOS Method: Same as Sign Control. Vehicle movement LOS values are based on average delay and v/c ratio (degree of saturation) per movement LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Intersection and Approach LOS values are based on average delay for all movements (v/c not used as specified in HCM 2010). Roundabout Capacity Model: SIDRA Standard. SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. Gap-Acceptance Capacity: SIDRA Standard (Akçelik M3D). HV (%) values are calculated for All Movement Classes of All Heavy Vehicle Model Designation. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :07:36 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\SidraFiles\with 11.5 percent trucks\roundabout Alt 2A at Recker and Thornhill 2040 AM revised sip6

86 MOVEMENT SUMMARY Site: Recker at Thornhill Alt A 2040 PM Roundabout Roundabout Movement Performance - Vehicles Mov OD Demand Flows Deg. Average Level of 95% Back of Queue Prop. Effective Average ID Mov Total HV Satn Delay Service Vehicles Distance Queued Stop Rate Speed veh/h % v/c sec veh ft per veh mph South: Recker Hwy 3 L LOS B T LOS A Approach LOS A North: Recker Hwy 4 T LOS A R LOS A Approach LOS A West: Thornhill Road 5 L LOS C R LOS C Approach LOS C All Vehicles LOS B Level of Service (LOS) Method: Delay & v/c (HCM 2010). Roundabout LOS Method: Same as Sign Control. Vehicle movement LOS values are based on average delay and v/c ratio (degree of saturation) per movement LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Intersection and Approach LOS values are based on average delay for all movements (v/c not used as specified in HCM 2010). Roundabout Capacity Model: SIDRA Standard. SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. Gap-Acceptance Capacity: SIDRA Standard (Akçelik M3D). HV (%) values are calculated for All Movement Classes of All Heavy Vehicle Model Designation. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :09:19 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\SidraFiles\with 11.5 percent trucks\roundabout Alt 2A at Recker and Thornhill 2040 PM Revised sip6

87 MOVEMENT SUMMARY Site: Recker at Thornhill Alt B 2020 AM Roundabout Roundabout Movement Performance - Vehicles Mov OD Demand Flows Deg. Average Level of 95% Back of Queue Prop. Effective Average ID Mov Total HV Satn Delay Service Vehicles Distance Queued Stop Rate Speed veh/h % v/c sec veh ft per veh mph South: Recker Hwy 3 L LOS B T LOS A Approach LOS A North: Recker Hwy 4 T LOS A R LOS A Approach LOS A West: Thornhill Road 5 L LOS B R LOS A Approach LOS B All Vehicles LOS A Level of Service (LOS) Method: Delay & v/c (HCM 2010). Roundabout LOS Method: Same as Sign Control. Vehicle movement LOS values are based on average delay and v/c ratio (degree of saturation) per movement LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Intersection and Approach LOS values are based on average delay for all movements (v/c not used as specified in HCM 2010). Roundabout Capacity Model: SIDRA Standard. SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. Gap-Acceptance Capacity: SIDRA Standard (Akçelik M3D). HV (%) values are calculated for All Movement Classes of All Heavy Vehicle Model Designation. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :16:51 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\SidraFiles\with 11.5 percent trucks\roundabout Alt 2B at Recker and Thornhill 2020 AM Revised sip6

88 MOVEMENT SUMMARY Site: Recker at Thornhill Alt B 2020 PM Roundabout Roundabout Movement Performance - Vehicles Mov OD Demand Flows Deg. Average Level of 95% Back of Queue Prop. Effective Average ID Mov Total HV Satn Delay Service Vehicles Distance Queued Stop Rate Speed veh/h % v/c sec veh ft per veh mph South: Recker Hwy 3 L LOS B T LOS A Approach LOS A North: Recker Hwy 4 T LOS A R LOS A Approach LOS A West: Thornhill Road 5 L LOS B R LOS A Approach LOS B All Vehicles LOS A Level of Service (LOS) Method: Delay & v/c (HCM 2010). Roundabout LOS Method: Same as Sign Control. Vehicle movement LOS values are based on average delay and v/c ratio (degree of saturation) per movement LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Intersection and Approach LOS values are based on average delay for all movements (v/c not used as specified in HCM 2010). Roundabout Capacity Model: SIDRA Standard. SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. Gap-Acceptance Capacity: SIDRA Standard (Akçelik M3D). HV (%) values are calculated for All Movement Classes of All Heavy Vehicle Model Designation. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :20:01 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\SidraFiles\with 11.5 percent trucks\roundabout Alt 2B at Recker and Thornhill 2020 PM Revised sip6

89 MOVEMENT SUMMARY Site: Recker at Thornhill Alt B 2040 AM Roundabout Roundabout Movement Performance - Vehicles Mov OD Demand Flows Deg. Average Level of 95% Back of Queue Prop. Effective Average ID Mov Total HV Satn Delay Service Vehicles Distance Queued Stop Rate Speed veh/h % v/c sec veh ft per veh mph South: Recker Hwy 3 L LOS B T LOS A Approach LOS A North: Recker Hwy 4 T LOS A R LOS A Approach LOS A West: Thornhill Road 5 L LOS C R LOS B Approach LOS C All Vehicles LOS A Level of Service (LOS) Method: Delay & v/c (HCM 2010). Roundabout LOS Method: Same as Sign Control. Vehicle movement LOS values are based on average delay and v/c ratio (degree of saturation) per movement LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Intersection and Approach LOS values are based on average delay for all movements (v/c not used as specified in HCM 2010). Roundabout Capacity Model: SIDRA Standard. SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. Gap-Acceptance Capacity: SIDRA Standard (Akçelik M3D). HV (%) values are calculated for All Movement Classes of All Heavy Vehicle Model Designation. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :22:30 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\SidraFiles\with 11.5 percent trucks\roundabout Alt 2B at Recker and Thornhill 2040 AM revised sip6

90 MOVEMENT SUMMARY Site: Recker at Thornhill Alt B 2040 PM Roundabout Roundabout Movement Performance - Vehicles Mov OD Demand Flows Deg. Average Level of 95% Back of Queue Prop. Effective Average ID Mov Total HV Satn Delay Service Vehicles Distance Queued Stop Rate Speed veh/h % v/c sec veh ft per veh mph South: Recker Hwy 3 L LOS B T LOS A Approach LOS A North: Recker Hwy 4 T LOS A R LOS A Approach LOS A West: Thornhill Road 5 L LOS C R LOS B Approach LOS C All Vehicles LOS A Level of Service (LOS) Method: Delay & v/c (HCM 2010). Roundabout LOS Method: Same as Sign Control. Vehicle movement LOS values are based on average delay and v/c ratio (degree of saturation) per movement LOS F will result if v/c > 1 irrespective of movement delay value (does not apply for approaches and intersection). Intersection and Approach LOS values are based on average delay for all movements (v/c not used as specified in HCM 2010). Roundabout Capacity Model: SIDRA Standard. SIDRA Standard Delay Model is used. Control Delay includes Geometric Delay. Gap-Acceptance Capacity: SIDRA Standard (Akçelik M3D). HV (%) values are calculated for All Movement Classes of All Heavy Vehicle Model Designation. SIDRA INTERSECTION 6.1 Copyright Akcelik and Associates Pty Ltd sidrasolutions.com Organisation: RUMMEL KLEPPER & KAHL LLP Processed: Monday, January 09, :23:51 PM Project: C:\Project Files\D1\SR 655 Recker Hwy\Files for Roundabout Resubmittal\SidraFiles\with 11.5 percent trucks\roundabout Alt 2B at Recker and Thornhill 2040 PM Revised sip6

91 APPENDIX C-C NCHRP 672 Reference Materials

92 Roundabouts: An Informational Guide Exhibit 6-46 Vehicle Path Radii Recommended maximum theoretical entry design speeds for roundabouts at various intersection site categories are provided in Exhibit Exhibit 6-47 Recommended Maximum Entry Design Speeds Site Category Mini-Roundabout Single Lane Multilane Recommended Maximum Theoretical Entry Design Speed 20 mph (30 km/h) 25 mph (40 km/h) 25 to 30 mph (40 to 50 km/h) Roundabout speed is determined by the fastest path allowed by the geometry. Through movements are usually the fastest path, but sometimes right-turn paths are more critical. Draw the fastest path for all roundabout approaches Construction of Vehicle Paths To determine the speed of a roundabout, the fastest path allowed by the geometry is drawn. This is the smoothest, flattest path possible for a single vehicle, in the absence of other traffic and ignoring all lane markings, traversing through the entry, around the central island, and out the exit. The design speed of the roundabout is determined from the smallest radius along the fastest allowable path. The smallest radius usually occurs on the circulatory roadway as the vehicle curves to the left around the central island. A vehicle is assumed to be 6 ft (2 m) wide and maintain a minimum clearance of 2 ft (0.5 m) from a roadway centerline or concrete curb and flush with a painted edge line (3). Thus the centerline of the vehicle path is drawn with the following distances to the particular geometric features: 5 ft (1.5 m) from a concrete curb, 5 ft (1.5 m) from a roadway centerline, and 3 ft (1.0 m) from a painted edge line. Exhibit 6-48 and Exhibit 6-49 illustrate the construction of the fastest vehicle paths at a single-lane roundabout and at a multilane roundabout, respectively. Exhibit 6-50 provides an example of an approach at which the right-turn path is Page 6-54 Chapter 6/Geometric Design

93 Roundabouts: An Informational Guide Vehicle Speed Estimation The relationship between travel speed and horizontal curvature is documented in the AASHTO Green Book (4). Both superelevation and the side friction factor affect the speed of a vehicle. Side friction varies with vehicle speed and can be determined in accordance with AASHTO guidelines. The most common superelevation values encountered are and 0.02, corresponding to 2% cross slope. Equation 6-1 and Equation 6-2 provide a simplified relationship between speed and radius for these two common superelevation rates that incorporates the AASHTO relationship and side friction factors. Exhibit 6-52 illustrates the speed radius relationship in a graphical format. Additional information regarding the relationship of speed to superelevation and side friction is provided in Appendix D. V = R , for e= V = R , for e= Equation 6-1 Equation 6-2 where V = predicted speed, mph; R = radius of curve, ft; and e = superelevation, ft/ft Exhibit 6-52 Speed Radius Relationship 30 Speed (mph) Radius (ft) e=+0.02 e=-0.02 The speed radius relationship given above generally provides a reasonable prediction for the left-turn and through movement circulating speeds. However, this method does not consider the effects of deceleration and acceleration and therefore may overpredict entry and exit speeds in cases where the path radius is large (1). To better predict actual entry speeds, Equation 6-3 may be used to account for deceleration of vehicles from the entering (R 1 ) speed to the circulating (R 2 ) Chapter 6/Geometric Design Page 6-57

94 Roundabouts: An Informational Guide speed. Analysts should use caution in using deceleration as a limiting factor to establish entry speeds for design. To promote safe design, deflection of the R 1 path radius should be the primary method for controlling entry speed. Therefore, while Equation 6-3 may provide an improved estimate of actual speed achieved at entry, for design purposes it is recommended that predicted speeds from Equation 6-1 be used. Equation 6-3 V 1 V1 = min pbase 2 ( 2 ) V 2a d where V 1 = entry speed, mph; V 1pbase = V 1 speed predicted based on path radius, mph; V 2 = circulatory speed for through vehicles predicted based on path radius, mph; a 12 = deceleration between the point of interest along V 1 path and the midpoint of V 2 path = 4.2 ft/s 2 ; and d 12 = distance along the vehicle path between the point of interest along V 1 path and the midpoint of V 2 path, ft. When identifying the predicted speed for the exit radius, R 3, the acceleration effects of vehicles can have a more prominent effect on the outcome of the estimated speed. At locations with a large radius or tangential exit, the measured R 3 radius will be so large that the acceleration characteristics of the vehicle will govern the actual speeds that can be achieved. Therefore, tangential exits do not inherently result in excessive exit speeds as compared to exits with some curvature, provided that circulating speeds are low and the distance to the point of interest on the exit (typically the crosswalk) is short. While it is desirable to provide some degree of curvature on the exit to reduce the visual appearance of a straight shot, recent U.S. research indicates that such curvature does not appear to always be the controlling factor for exit speeds (1). Exit speed can be estimated using Equation 6-4. Equation 6-4 V 3 V3 = min pbase 2 ( 2 ) V 2a d where V 3 = exit speed, mph; V 3pbase = V 3 speed predicted based on path radius, mph; V 2 = circulatory speed for through vehicles predicted based on path radius, mph; a 23 = acceleration between the midpoint of V 2 path and the point of interest along V 3 path = 6.9 ft/s 2 ; and d 23 = distance along the vehicle path between midpoint of V 2 path and point of interest along V 3 path, ft. Page 6-58 Chapter 6/Geometric Design

95 APPENDIX D-D Wisconsin DOT: Creating Roundabout Fastest Paths (Spline Curves) in Microstation Version 8i

96 FDM Attachment 50.2 Creating Roundabout Fastest Paths (Spline Curves) in Microstation Version 8i Creating Roundabout Fastest Paths (Spline Curves) in Microstation Version 8i Step 1: Copy Curb Offsets Create the curb offsets as shown in FDM , Figure 1 using the move/copy parallel function. Figure 1 Move/Copy Parallel A. 5 from left side face of curb (or 3 from painted C/L or flange line of curb & gutter) on each approach. B. 5 from face of curb on driver s right side at each entry and exit. C. 5 from central island face of curb. Face of curb for the Type R and T is 6-inches from the back of curb. D. Not less than 165 from roundabout Inscribed Circle Diameter (ICD). Typically this distance may be 165 but could be more depending on how a driver would approach the yield line at high speed. To determine the speed of a roundabout, the fastest path allowed by the geometry is drawn. This is the most realistic, smoothest path possible for a single vehicle, in the absence of other traffic and ignoring all lane markings, traversing through the entry, around the central island and out the exit (R1). Figure 2 Offsets for Fastest Path Step 2: Draw Spline Curve There are a couple different ways to set up spline functions as shown below: March 4, 2013 Attachment 50.2 Page 1

97 FDM Attachment 50.2 Creating Roundabout Fastest Paths (Spline Curves) in Microstation Version 8i Figure 3 Place B-spline Curve Draw the spline curve for the through movement as shown below, using near snaps for all points picked: Figure 4 Spline Curve through movement Clicking sequence: 1. Choose points A through C on the first 5 curb offset from splitter island (tentative snap, then left click to accept). Choose 3 points that are approximately 25 feet apart that will approximate the path of an approaching vehicle. It is advisable to choose two points outside of the 165 line and one on the 165 line. 2. Choose point D on the 5 curb offset from entry curve (tentative snap, then left click to accept). 3. Choose point E on the 5 curb offset from central island (tentative snap, then left click to accept). 4. Choose point F on the 5 curb offset from exit curve (tentative snap, then left click to accept). 5. Choose points G through I, or G 1 through I 1,on the 5 offset from the right side exit curb (tentative snap, then left click to accept). There may be times when it is appropriate to check the left side instead of the right side. The side is dependent on the anticipated driving path of the vehicle and the roadway alignment. Choose 3 points that are approximately 5 feet apart that will approximate the path of an exiting vehicle. Two points should be outside the 165 line and one point inside of the 165 line. 6. Right click to end the spline curve. MicroStation will then jump back to the start of the curve. 7. Snap to a point just upstream from the start of the spline at point J (tentative snap, then left click to accept). This forces the beginning of the spline to be tangent to the splitter island curb. 8. Microstation will then jump to the end of the curve. 9. Snap to a point just downstream from the end of the spline at point K (tentative snap, then left click to accept). This forces the end of the spline to be tangent to the splitter island curb. March 4, 2013 Attachment 50.2 Page 2

98 FDM Attachment 50.2 Creating Roundabout Fastest Paths (Spline Curves) in Microstation Version 8i Step 3: Modify Spline Curve Check the spline created in Step 2 above to see if it violates the 5 curb offsets. This can be done two different ways. One with the Measure Distance tool using the Minimum Between function. Measure the distance between the face of curb and the spline curve at points A through I shown above. Figure 5 Measure Distance The second is to zoom into the areas of points A through I and visually inspect whether the spline curve violates the curb offsets. In most cases, the spline may slightly violate the 5 curb offset. Use engineering judgment to determine if the spline will need to be modified. As shown, the spline should be modified. Modify the spline: If the spline is between the curb offset and the curb or outside of the curb offset, it will need to be modified. Figure 6 Spline curve between curb offset and the curb Using the tool Modify Element shown below grab the spline curve and pull it to a desired location on top of the curb offset. This may need to be done a few times before the spline is on top of all the curb offsets. Figure 7 Modify Element Evaluate the spline as a whole to see if it looks like it is the path that a vehicle would use. Oftentimes, the beginning or end of the spline may need to be pulled further away from the roundabout itself. March 4, 2013 Attachment 50.2 Page 3

99 FDM Attachment 50.2 Creating Roundabout Fastest Paths (Spline Curves) in Microstation Version 8i Step 4: Measure R-values 1. Once an acceptable spline is created, fit arcs to the spline to measure the R-values using the Place Arc tool with the Edge method. Figure 8 Place Arc 2. Using Near snaps, fit an arc onto the spline at a point that appears to be the tightest portion of the spline. This should occur prior to the yield line and not more than 165 from the yield line. 3. Check the length of the arc. Per FDM 11-26, Figure 30.2 if the arc is not 65 to 80 feet long, recreate it to try to get an arc that is 65 to 80 feet long. 4. Measure the radius of the arc. 5. Repeat to find R-values for R-1, R-2, and R To find R-4, simply measure the radius of the 5 curb offset from the central island. 7. To find R-5, create a spline that is tangential to the three curb offsets that define the R5 path (the 5 splitter island offset on the entry, the 5 offset on the inside of the right turn, and the 5 splitter island offset on the exit). Check that the arc does not cross any curb offsets, especially when the geometry of the right turn movement is created with multiple arcs. Below is a diagram of a typical R5 spline. Figure 9 Example R5 Spline March 4, 2013 Attachment 50.2 Page 4