EXECUTIVE SUMMARY. Page 1 of 6

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2 EXECUTIVE SUMMARY The purpose of this report is to identify conformance with the original traffic impact study for the proposed retail development on Lot 5 of Riverdale Retail Filing No. 1 located on the northeast corner of E 128 Ave and Holly Street. The 128th Avenue/Holly Street Retail Development Traffic Impact Analysis was completed in January, 26 by Felsburg Holt &Ullevig (the FHU Study ). The parcel is currently undeveloped and is approximately 1.55 acres. The FHU Study projected for Lot 5 the land use of 4, SF of fast-food with drive-thru generating 1,98 vehicles per day (vpd) with 21 AM peak hour and 14 PM peak hour. The development of Lot 5 is currently proposed to be a multi-tenant retail center of approximately 8,4 SF. The proposed project is projected to generate 373 vpd with 58 AM peak hour and 23 PM peak hour. Therefore, projected traffic for the proposed development is less than the original FHU study for Lot 5 from both a daily and peak-hour perspective. All potential traffic impacts with the proposed project have been previously addressed within the FHU Study. However, at the request of the City of Thornton, additional analysis was requested of the South Access Driveway on E 128th Ave using existing traffic counts and projecting forward to design year 236. Access to the project on Lot 5 is proposed to be gained by construction a connection with the existing parking lot and internal through-access road. This internal through-access road intersects with E 128th Ave on the south side of the development and with Holly Street on the west side of the development and it is the intersection on the south side that was analyzed as a part of this letter. The existing intersection analyzed in this report is E 128th Ave and Riverdale South Access, a ¾-movement stop-controlled intersection. It currently has two restricted movements (eastbound left-turn and southbound right-turn) which both operate in 216 with acceptable LOS A or B. Both restricted movements are projected to continue to operate with acceptable LOS C or better after the addition of the traffic from the development through horizon year 236. Both restricted movements queue lengths through year 236 are projected to be considerably less than the queue storage provided for the two restricted movements. Therefore, based on the analyses contained in this traffic letter it is concluded that the studyarea roadway system can accommodate the proposed Riverdale Lot 5 multi-use retail development with no additional access improvements and with negligible impact on the studyarea roadway system. Page 1 of 6

3 TABLE OF CONTENTS I. EXISTING CONDITIONS... 3 A. Existing Traffic Volumes... 3 II. BACKGROUND TRAFFIC... 3 A. Background Traffic Volumes... 3 B. Background Traffic Operational Analysis... 3 III. PROJECT DEVELOPMENT... 4 A. Trip Generation... 4 B. Trip Distribution... 4 C. Trip Assignment... 4 IV. TOTAL TRAFFIC... 4 V. PROJECT ANALYSIS... 5 A. Operational Analysis... 5 B. Queue Lengths and Storage Required... 5 C. Traffic Signal Warrant 3 Analysis... 5 VI. SUMMARY... 6 LIST OF TABLES Table 1: Trip Generation Riverdale Lot Table 2: Summary of Results Queue Storage... 8 Table 3: Summary of Results Intersection Capacity Analysis... 9 FIGURES 1 Vicinity Map 2 Riverdale Shopping Center Site Plan 3 Riverdale Lot #5 Conceptual Plan 4 216, 218, 236 Volumes, LOS 216 Existing Traffic Volumes 218 Background Traffic Volumes 236 Background Traffic Volumes 216 Existing Traffic Operational Conditions 218 Background Traffic Operational Conditions 236 Background Traffic Operational Conditions 5 216, 218, 236 Distribution, Assignment, Volumes, LOS Site-Generated Trip Distribution Site-Generated Trip Assignment 218 Total Traffic Volumes 236 Total Traffic Volumes 218 Total Traffic Operational Conditions 236 Total Traffic Operational Conditions APPENDIX A APPENDIX B APPENDIX C 216 EXISTING TRAFFIC VOLUME COUNTS INTERSECTION CAPACITY ANALYSIS WORKSHEETS CITY OF THORNTON COMMENTS AND HKS RESPONSES Page 2 of 6

4 1 LEGEND EXISTING ROADWAY

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7 I. EXISTING CONDITIONS A. Existing Traffic Volumes Existing (216) peak-hour intersection turning-movement traffic-volume counts were collected for this study at the intersection of E 128 th Ave and Riverdale South Access Driveway in November, 216. A summary of the existing (216) peak-hour intersection turning-movement traffic volume counts is graphically illustrated in Figure 4. Detailed traffic-volume-count data are provided in Appendix A. II. BACKGROUND TRAFFIC A. Background Traffic Volumes Background traffic and forecasts for the 218 and 236 analysis horizons were developed for this study utilizing the following: For the purposes of this study it is assumed that peak-hour distribution of background intersection approach traffic (left turn, through, right turn) will remain constant through the 218 and 236 analysis horizons. The Transportation Master Plan for the City of Thornton projects traffic on E 128 th Ave in 235 as 13, vpd ADT. In July, 214, DRCOG traffic counts showed E 128 th Ave east of Holly Street as 14,436 vpd ADT which is greater than the Thornton projection for 236. Nevertheless, City of Thornton guidelines indicate an annual growth rate of +3.%/year shall be used on E 128 th Ave to estimate traffic for 218 and 236 using 216 counts as a starting point. Figure 4 graphically illustrates the projected background-traffic volumes for the 218 and 236 analysis horizons. B. Background Traffic Operational Analysis In order to establish a base condition in which to evaluate the impact of the traffic generated by the proposed development on the study-area intersections, peak-hour capacity analyses were performed for the 216 existing, and the 218 and 236 background traffic conditions. These analyses utilized the methodologies contained in the Highway Capacity Manual 21 (HCM) employing Synchro 8. software and resulted in a qualitative measure of the operational characteristics of the intersection described by a letter designation ranging from A to F known as Level of Service (LOS). LOS A represents ideal free flow operating conditions, whereas LOS F represents excessive congestion and delay. Unsignalized intersection capacity analysis reports a LOS designation for each impeded intersection movement. Signalized intersection capacity analysis reports the overall LOS designation for the intersection as well as for each lane group and approach. LOS D is considered the minimum acceptable standard of operation. The study-area intersection of E 128 th Ave and Riverdale South Access Driveway was analyzed for 216 existing traffic and the 218 and 236 analysis horizon background-traffic conditions. The results of this background traffic operational analyses are summarized graphically for the 216 existing, 218 background and 236 background analysis horizons in Figure 4. A summary of the results of the intersection capacity analyses is provided in Table 2 and detailed Synchro 8. software intersection capacity analysis reports in Appendix B. Page 3 of 6

8 6(49) 58(697) 8(12) S ACCESS DR 4(57) 621(669) 6(52) 538(739) 8(18) 4(6) 658(79) TH AVE S ACCESS DR 128TH AVE 1(78) 813(1115) 13(163) S ACCESS DR 6(91) 994(17) 128TH AVE 216 EXISTING TRAFFIC VOLUMES 218 BACKGROUND TRAFFIC VOLUMES 236 BACKGROUND TRAFFIC VOLUMES b(b) S ACCESS DR b(b) S ACCESS DR b(c) S ACCESS DR a(a) 1 128TH AVE a(a) 1 128TH AVE b(b) 1 128TH AVE 216 EXISTING TRAFFIC OPERATIONAL CONDITIONS 218 BACKGROUND TRAFFIC OPERATIONAL CONDITIONS 236 BACKGROUND TRAFFIC OPERATIONAL CONDITIONS LEGEND EXISTING ROADWAY 1 INTERSECTION NUMBER STOP SIGN ##(##) a(a) AM(PM) HR VOLUME LANE GROUP LOS am(pm)

9 III. PROJECT DEVELOPMENT A. Trip Generation The trip-generation projection for the proposed Riverdale Lot 5 development was estimated utilizing the publication Trip Generation, 9 th Edition, Institute of Transportation Engineers. Estimates of total daily traffic volume and AM and PM peak-hour traffic volumes were calculated. Trip-generation reductions due to transportation demand management or transit use were not considered. For the purposes of this study it is assumed that the subject parcel will be fully developed by 218 as a 8,4 square foot multi-tenant retail development. The proposed project is projected to generate 373 daily vehicle trips of which 58 are projected to be generated during the AM peak hour and approximately 23 are projected to be generated during the PM peak hour. See Table 1. TABLE 1 RIVERDALE LOT NO. 5 RETAIL DEVELOPMENT Trip Generation Land Use Intensity ITE Daily A.M. Peak Hour (vph) P.M. Peak Hour (vph) Code (vpd) Total % In % Out In Out Total % In % Out In Out Parcel 1 Speciality Retail Center 84 SF % 52% % 56% Parcel 1 Total Notes: 1. Trip Generation Projections are based on ITE Trip Generation, 9th Edition using Average Rates B. Trip Distribution The distribution of the estimated vehicle trips generated by the land uses for this study was established based on the current and projected future traffic patterns on the surrounding transportation system, efficiency of access to the principal transportation corridors serving the area, and the potential trip origins/destinations for the proposed land use for the subject property. Figure 5 graphically illustrates the project-generated trip-distribution patterns for the development. C. Trip Assignment The vehicular traffic volumes estimated to be generated by the proposed Riverdale Lot 5 development were assigned to the study-area roadways and intersections utilizing the tripdistribution analysis described above. Figure 5 also graphically illustrates the site-generated trip assignment for the development. IV. TOTAL TRAFFIC Total-traffic forecast for the 218 analysis scenario was computed by combining the 218 background-traffic volumes with the associated projected site-generated traffic volumes. Totaltraffic forecast for the 236 analysis scenario was computed by combining the 236 background-traffic volumes with the associated projected site-generated traffic volumes. Figure 5 graphically illustrates the total-traffic forecasts for the study-area intersection for the 218 and 236 analysis horizons. Page 4 of 6

10 5% S ACCESS DR 25% 5% 128TH AVE 14(6) 25% 8(3) 15(6) S ACCESS DR (3) 128TH AVE 2(58) 546(742) 23(114) S ACCESS DR 11(63) 658(79) 128TH AVE SITE-GENERATED TRIP DISTRIBUTION SITE-GENERATED TRIP ASSIGNENT 218 TOTAL TRAFFIC VOLUMES 24(84) 821(1118) 28(169) S ACCESS DR 1 13(94)) 994(17) 128TH AVE a(a) b(b) S ACCESS DR 1 128TH AVE b(b) b(c) S ACCESS DR 1 128TH AVE 236 TOTAL TRAFFIC VOLUMES 218 TOTAL TRAFFIC OPERATIONAL CONDITIONS 236 TOTAL TRAFFIC OPERATIONAL CONDITIONS LEGEND x% ##(##) a(a) EXISTING ROADWAY 1 INTERSECTION NUMBER STOP SIGN SITE-GENERATED TRIP DISTRIBUTION AM(PM) HR VOLUME LANE GROUP LOS am(pm)

11 V. PROJECT ANALYSIS A. Operational Analysis To evaluate the impact of the proposed land use for the subject property on the study-area intersection, peak-hour intersection capacity analyses for total-traffic conditions were performed for the 218 and 236 analysis horizons. A summary of the results of the intersection capacity analysis is provided in Table 3 and detailed Synchro 8. software intersection capacity analysis reports in Appendix B. Summary of Results: The E 128 th Ave and South Access Driveway intersection is projected to continue to operate at acceptable levels of service (LOS C or better for all restricted movements) in the 218 and 236 Total Traffic analysis scenarios. B. Queue Lengths and Storage Required Synchro 8 and 95 th percentile queue lengths were used to analyze and project queue lengths and associated queue storage needs. The analysis results indicate all projected queue lengths through 236 are less than the queue storage already provided. See Table 2 for a summary of this analysis. TABLE 2 QUEUE LENGTHS AND ASSOCIATED STORAGE NEEDED SYNCHRO 95 TH PERCENTILE METHOD INTERSECTION EXISTING STORAGE (FT) C. Traffic Signal Warrant 3 Analysis INTERSECTION CONTROL YEAR 216 BACKGOUND TRAFFIC QUEUE LENGTH (FT) 95TH PERCENTILE AM PM YEAR 218 BACKGROUND TRAFFIC QUEUE LENGTH (FT) 95TH PERCENTILE AM PM YEAR 236 BACKGROUND TRAFFIC QUEUE LENGTH (FT) 95TH PERCENTILE AM PM YEAR 218 TOTAL TRAFFIC QUEUE LENGTH (FT) 95TH PERCENTILE AM YEAR 236 TOTAL TRAFFIC QUEUE LENGTH (FT) 95TH PERCENTILE PM AM PM 1. E 128TH AVE / SOUTH ACCESS DRIVEWAY TWSC a EB L b SB R NOTES: 1 Vehicle Length = 25 feet When evaluating future traffic conditions, the only Traffic Signal Warrant that can be evaluated is Warrant 3 (Peak Hour Volume) since only peak-hour volumes are projected for a new land use. The MUTCD states that Warrant 3 should only be used for analyzing intersections that have unusual traffic characteristics such as when large numbers of vehicles are discharged over a short time frame. This condition does not appear to be met at the study intersection and therefore under current traffic generation sources this warrant does not apply. Page 5 of 6

12 VI. SUMMARY Based on the analyses contained in this traffic study it is concluded that the study-area roadway system can accommodate the proposed Riverdale Lot No. 5 with negligible impact on the studyarea roadway system. INTERSECTION Table 3 Summary of Results - Intersection Capacity Analysis INTERSECTION CONTROL 216 EXISTING TRAFFIC LEVEL OF SERVICE AM LOS PM LOS 218 BACKGROUND TRAFFIC LEVEL OF SERVICE 1. E 128TH AVENUE / SOUTH DRIVEWAY TWSC a. EB L A A A A A A B B B B b. SB R STOP B B B B B B B C B C AM LOS PM LOS 218 TOTAL TRAFFIC LEVEL OF SERVICE AM LOS PM LOS 236 BACKGROUND TRAFFIC LEVEL OF SERVICE AM LOS PM LOS 236 TOTAL TRAFFIC LEVEL OF SERVICE AM LOS PM LOS Page 6 of 6

13 APPENDIX A 216 EXISTING TRAFFIC VOLUME COUNTS

14 8 (33) Location: 1 BELLCO CREDIT ACCESS & E 128TH AVE AM Date and Start Time: Tuesday, November 15, 216 Peak Hour: Peak 15-Minutes: 7: AM - 8: AM 7:3 AM - 7:45 AM Peak Hour - All Vehicles (19) (31) BELLCO CREDIT ACCESS Peak Hour - Pedestrians/Bicycles on Crosswalk 1 E 128TH AVE (1,127) (921) 6 58 W N.89 S E (1,124) (96) W 1 N S E E 128TH AVE E 128TH AVE Note: Total study counts contained in parentheses. Traffic Counts Interval Start Time E 128TH AVE E 128TH AVE BELLCO CREDIT ACCESS Eastbound Westbound Northbound Southbound U-Turn Left Thru Right U-Turn Left Thru Right U-Turn Left Thru Right U-Turn Left Thru Right Total Rolling Pedestrain Crossings Hour West East South North 7: AM ,147 7:15 AM ,124 7:3 AM ,81 7:45 AM : AM :15 AM :3 AM :45 AM Count Total , ,64 Peak Hour ,147

15 (33) Location: 1 BELLCO CREDIT ACCESS & E 128TH AVE PM Date and Start Time: Tuesday, November 15, 216 Peak Hour: Peak 15-Minutes: 4:45 PM - 5:45 PM 5: PM - 5:15 PM Peak Hour - All Vehicles (23) (23) BELLCO CREDIT ACCESS Peak Hour - Pedestrians/Bicycles on Crosswalk 3 1 E 128TH AVE (1,493) (1,449) W N.96 S E (1,41) (1,366) W 4 N S E E 128TH AVE E 128TH AVE Note: Total study counts contained in parentheses. Traffic Counts Interval Start Time E 128TH AVE E 128TH AVE BELLCO CREDIT ACCESS Eastbound Westbound Northbound Southbound U-Turn Left Thru Right U-Turn Left Thru Right U-Turn Left Thru Right U-Turn Left Thru Right Total Rolling Pedestrain Crossings Hour West East South North 4: PM ,491 4:15 PM ,541 4:3 PM ,572 4:45 PM , : PM ,571 5:15 PM :3 PM :45 PM Count Total 96 1,353 1, ,62 4 Peak Hour ,576 4

16 APPENDIX B INTERSECTION CAPACITY ANALYSIS WORKSHEETS

17 HCM 21 TWSC Riverdale 128th and Holly 1: E 128th Ave & South Driveway 11/17/216 Intersection Int Delay, s/veh.1 Movement EBL EBT WBT WBR SBL SBR Vol, veh/h Conflicting Peds, #/hr Sign Control Free Free Free Free Stop Stop RT Channelized - None - None - None Storage Length Veh in Median Storage, # Grade, % Peak Hour Factor Heavy Vehicles, % Mvmt Flow Major/Minor Major1 Major2 Minor2 Conflicting Flow All Stage Stage Critical Hdwy Critical Hdwy Stg Critical Hdwy Stg Follow-up Hdwy Pot Cap-1 Maneuver Stage Stage Platoon blocked, % Mov Cap-1 Maneuver Mov Cap-2 Maneuver Stage Stage Approach EB WB SB HCM Control Delay, s HCM LOS B Minor Lane/Major Mvmt EBL EBT WBT WBR SBLn1 Capacity (veh/h) HCM Lane V/C Ratio HCM Control Delay (s) HCM Lane LOS A B HCM 95th %tile Q(veh) Background AM.syn Synchro 8 Report HKS 1691 Page 2

18 HCM 21 TWSC Riverdale 128th and Holly 1: E 128th Ave & South Driveway 11/17/216 Intersection Int Delay, s/veh 1.1 Movement EBL EBT WBT WBR SBL SBR Vol, veh/h Conflicting Peds, #/hr Sign Control Free Free Free Free Stop Stop RT Channelized - None - None - None Storage Length Veh in Median Storage, # Grade, % Peak Hour Factor Heavy Vehicles, % Mvmt Flow Major/Minor Major1 Major2 Minor2 Conflicting Flow All Stage Stage Critical Hdwy Critical Hdwy Stg Critical Hdwy Stg Follow-up Hdwy Pot Cap-1 Maneuver Stage Stage Platoon blocked, % Mov Cap-1 Maneuver Mov Cap-2 Maneuver Stage Stage Approach EB WB SB HCM Control Delay, s HCM LOS B Minor Lane/Major Mvmt EBL EBT WBT WBR SBLn1 Capacity (veh/h) HCM Lane V/C Ratio HCM Control Delay (s) HCM Lane LOS A B HCM 95th %tile Q(veh) Background PM.syn Synchro 8 Report HKS 1691 Page 2

19 HCM 21 TWSC Riverdale 128th and Holly 1: E 128th Ave & South Driveway 1/24/217 Intersection Int Delay, s/veh.1 Movement EBL EBT WBT WBR SBL SBR Vol, veh/h Conflicting Peds, #/hr Sign Control Free Free Free Free Stop Stop RT Channelized - None - None - None Storage Length Veh in Median Storage, # Grade, % Peak Hour Factor Heavy Vehicles, % Mvmt Flow Major/Minor Major1 Major2 Minor2 Conflicting Flow All Stage Stage Critical Hdwy Critical Hdwy Stg Critical Hdwy Stg Follow-up Hdwy Pot Cap-1 Maneuver Stage Stage Platoon blocked, % Mov Cap-1 Maneuver Mov Cap-2 Maneuver Stage Stage Approach EB WB SB HCM Control Delay, s HCM LOS B Minor Lane/Major Mvmt EBL EBT WBT WBR SBLn1 Capacity (veh/h) HCM Lane V/C Ratio HCM Control Delay (s) HCM Lane LOS A B HCM 95th %tile Q(veh) Background AM.syn Synchro 8 Report HKS 1691 Page 1

20 HCM 21 TWSC Riverdale 128th and Holly 1: E 128th Ave & South Driveway 1/24/217 Intersection Int Delay, s/veh 1.1 Movement EBL EBT WBT WBR SBL SBR Vol, veh/h Conflicting Peds, #/hr Sign Control Free Free Free Free Stop Stop RT Channelized - None - None - None Storage Length Veh in Median Storage, # Grade, % Peak Hour Factor Heavy Vehicles, % Mvmt Flow Major/Minor Major1 Major2 Minor2 Conflicting Flow All Stage Stage Critical Hdwy Critical Hdwy Stg Critical Hdwy Stg Follow-up Hdwy Pot Cap-1 Maneuver Stage Stage Platoon blocked, % Mov Cap-1 Maneuver Mov Cap-2 Maneuver Stage Stage Approach EB WB SB HCM Control Delay, s HCM LOS B Minor Lane/Major Mvmt EBL EBT WBT WBR SBLn1 Capacity (veh/h) HCM Lane V/C Ratio HCM Control Delay (s) HCM Lane LOS A B HCM 95th %tile Q(veh) Background PM.syn Synchro 8 Report HKS 1691 Page 1

21 HCM 21 TWSC Riverdale 128th and Holly 1: E 128th Ave & South Driveway 1/24/217 Intersection Int Delay, s/veh.3 Movement EBL EBT WBT WBR SBL SBR Vol, veh/h Conflicting Peds, #/hr Sign Control Free Free Free Free Stop Stop RT Channelized - None - None - None Storage Length Veh in Median Storage, # Grade, % Peak Hour Factor Heavy Vehicles, % Mvmt Flow Major/Minor Major1 Major2 Minor2 Conflicting Flow All Stage Stage Critical Hdwy Critical Hdwy Stg Critical Hdwy Stg Follow-up Hdwy Pot Cap-1 Maneuver Stage Stage Platoon blocked, % Mov Cap-1 Maneuver Mov Cap-2 Maneuver Stage Stage Approach EB WB SB HCM Control Delay, s HCM LOS B Minor Lane/Major Mvmt EBL EBT WBT WBR SBLn1 Capacity (veh/h) HCM Lane V/C Ratio HCM Control Delay (s) HCM Lane LOS A B HCM 95th %tile Q(veh) Total AM.syn Synchro 8 Report HKS 1691 Page 1

22 HCM 21 TWSC Riverdale 128th and Holly 1: E 128th Ave & South Driveway 1/24/217 Intersection Int Delay, s/veh 1.2 Movement EBL EBT WBT WBR SBL SBR Vol, veh/h Conflicting Peds, #/hr Sign Control Free Free Free Free Stop Stop RT Channelized - None - None - None Storage Length Veh in Median Storage, # Grade, % Peak Hour Factor Heavy Vehicles, % Mvmt Flow Major/Minor Major1 Major2 Minor2 Conflicting Flow All Stage Stage Critical Hdwy Critical Hdwy Stg Critical Hdwy Stg Follow-up Hdwy Pot Cap-1 Maneuver Stage Stage Platoon blocked, % Mov Cap-1 Maneuver Mov Cap-2 Maneuver Stage Stage Approach EB WB SB HCM Control Delay, s HCM LOS B Minor Lane/Major Mvmt EBL EBT WBT WBR SBLn1 Capacity (veh/h) HCM Lane V/C Ratio HCM Control Delay (s) HCM Lane LOS A B HCM 95th %tile Q(veh) Total PM.syn Synchro 8 Report HKS 1691 Page 1

23 HCM 21 TWSC Riverdale 128th and Holly 1: E 128th Ave & South Driveway 1/24/217 Intersection Int Delay, s/veh.1 Movement EBL EBT WBT WBR SBL SBR Vol, veh/h Conflicting Peds, #/hr Sign Control Free Free Free Free Stop Stop RT Channelized - None - None - None Storage Length Veh in Median Storage, # Grade, % Peak Hour Factor Heavy Vehicles, % Mvmt Flow Major/Minor Major1 Major2 Minor2 Conflicting Flow All Stage Stage Critical Hdwy Critical Hdwy Stg Critical Hdwy Stg Follow-up Hdwy Pot Cap-1 Maneuver Stage Stage Platoon blocked, % Mov Cap-1 Maneuver Mov Cap-2 Maneuver Stage Stage Approach EB WB SB HCM Control Delay, s HCM LOS B Minor Lane/Major Mvmt EBL EBT WBT WBR SBLn1 Capacity (veh/h) HCM Lane V/C Ratio HCM Control Delay (s) HCM Lane LOS B B HCM 95th %tile Q(veh) Background AM.syn Synchro 8 Report HKS 1691 Page 1

24 HCM 21 TWSC Riverdale 128th and Holly 1: E 128th Ave & South Driveway 1/24/217 Intersection Int Delay, s/veh 1.5 Movement EBL EBT WBT WBR SBL SBR Vol, veh/h Conflicting Peds, #/hr Sign Control Free Free Free Free Stop Stop RT Channelized - None - None - None Storage Length Veh in Median Storage, # Grade, % Peak Hour Factor Heavy Vehicles, % Mvmt Flow Major/Minor Major1 Major2 Minor2 Conflicting Flow All Stage Stage Critical Hdwy Critical Hdwy Stg Critical Hdwy Stg Follow-up Hdwy Pot Cap-1 Maneuver Stage Stage Platoon blocked, % Mov Cap-1 Maneuver Mov Cap-2 Maneuver Stage Stage Approach EB WB SB HCM Control Delay, s HCM LOS C Minor Lane/Major Mvmt EBL EBT WBT WBR SBLn1 Capacity (veh/h) HCM Lane V/C Ratio HCM Control Delay (s) HCM Lane LOS B C HCM 95th %tile Q(veh) Background PM.syn Synchro 8 Report HKS 1691 Page 1

25 HCM 21 TWSC Riverdale 128th and Holly 1: E 128th Ave & South Driveway 1/24/217 Intersection Int Delay, s/veh.3 Movement EBL EBT WBT WBR SBL SBR Vol, veh/h Conflicting Peds, #/hr Sign Control Free Free Free Free Stop Stop RT Channelized - None - None - None Storage Length Veh in Median Storage, # Grade, % Peak Hour Factor Heavy Vehicles, % Mvmt Flow Major/Minor Major1 Major2 Minor2 Conflicting Flow All Stage Stage Critical Hdwy Critical Hdwy Stg Critical Hdwy Stg Follow-up Hdwy Pot Cap-1 Maneuver Stage Stage Platoon blocked, % Mov Cap-1 Maneuver Mov Cap-2 Maneuver Stage Stage Approach EB WB SB HCM Control Delay, s HCM LOS B Minor Lane/Major Mvmt EBL EBT WBT WBR SBLn1 Capacity (veh/h) HCM Lane V/C Ratio HCM Control Delay (s) HCM Lane LOS B B HCM 95th %tile Q(veh) Total AM.syn Synchro 8 Report HKS 1691 Page 1

26 HCM 21 TWSC Riverdale 128th and Holly 1: E 128th Ave & South Driveway 1/24/217 Intersection Int Delay, s/veh 1.6 Movement EBL EBT WBT WBR SBL SBR Vol, veh/h Conflicting Peds, #/hr Sign Control Free Free Free Free Stop Stop RT Channelized - None - None - None Storage Length Veh in Median Storage, # Grade, % Peak Hour Factor Heavy Vehicles, % Mvmt Flow Major/Minor Major1 Major2 Minor2 Conflicting Flow All Stage Stage Critical Hdwy Critical Hdwy Stg Critical Hdwy Stg Follow-up Hdwy Pot Cap-1 Maneuver Stage Stage Platoon blocked, % Mov Cap-1 Maneuver Mov Cap-2 Maneuver Stage Stage Approach EB WB SB HCM Control Delay, s HCM LOS C Minor Lane/Major Mvmt EBL EBT WBT WBR SBLn1 Capacity (veh/h) HCM Lane V/C Ratio HCM Control Delay (s) HCM Lane LOS B C HCM 95th %tile Q(veh) Total PM.syn Synchro 8 Report HKS 1691 Page 1

27 APPENDIX C CITY OF THORNTON COMMENTS AND HKS RESPONSES

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29 I. EXISTING CONDITIONS A. Existing Traffic Volumes Existing (216) peak-hour intersection turning-movement traffic-volume counts were collected for this study at the intersection of E 128 th Ave and Riverdale South Access Driveway in November, 216. A summary of the existing (216) peak-hour intersection turning-movement traffic volume counts is graphically illustrated in Figure 4. Detailed traffic-volume-count data are provided in Appendix A. II. BACKGROUND TRAFFIC A. Background Traffic Volumes Background traffic and forecasts for the 218 and 236 analysis horizons were developed for this study utilizing the following: For the purposes of this study it is assumed that peak-hour distribution of background intersection approach traffic (left turn, through, right turn) will remain constant through the 218 and 236 analysis horizons. The Transportation Master Plan for the City of Thornton projects traffic on E 128 th Ave in 235 as 13, vpd ADT. In July, 214, DRCOG traffic counts showed E 128 th Ave east of Holly Street as 14,436 vpd ADT which is greater than the Thornton projection for 236. Therefore, due to conflicting data, a conservative growth rate of +1.%/year was used on E 128 th Ave to estimate traffic for 218 and 236 using 216 counts as a starting point. Figure 4 graphically illustrates the projected background-traffic volumes for the 218 and 236 analysis horizons. B. Background Traffic Operational Analysis In order to establish a base condition in which to evaluate the impact of the traffic generated by the proposed development on the study-area intersections, peak-hour capacity analyses were performed for the 216 existing, and the 218 and 236 background traffic conditions. These analyses utilized the methodologies contained in the Highway Capacity Manual 21 (HCM) employing Synchro 8. software and resulted in a qualitative measure of the operational characteristics of the intersection described by a letter designation ranging from A to F known as Level of Service (LOS). LOS A represents ideal free flow operating conditions, whereas LOS F represents excessive congestion and delay. Unsignalized intersection capacity analysis reports a LOS designation for each impeded intersection movement. Signalized intersection capacity analysis reports the overall LOS designation for the intersection as well as for each lane group and approach. LOS D is considered the minimum acceptable standard of operation. The study-area intersection of E 128 th Ave and Riverdale South Access Driveway was analyzed for 216 existing traffic and the 218 and 236 analysis horizon background-traffic conditions. The results of this background traffic operational analyses are summarized graphically for the 216 existing, 218 background and 236 background analysis horizons in Figure 4. A summary of the results of the intersection capacity analyses is provided in Table 2 and detailed Synchro 8. software intersection capacity analysis reports in Appendix B. Page 3 of 6

30 V. PROJECT ANALYSIS A. Operational Analysis To evaluate the impact of the proposed land use for the subject property on the study-area intersection, peak-hour intersection capacity analyses for total-traffic conditions were performed for the 218 and 236 analysis horizons. A summary of the results of the intersection capacity analysis is provided in Table 3 and detailed Synchro 8. software intersection capacity analysis reports in Appendix B. Summary of Results: The E 128 th Ave and South Access Driveway intersection is projected to continue to operate at acceptable levels of service (LOS A or B for all restricted movements) in 218 and 236 Total Traffic analysis scenarios. B. Queue Lengths and Storage Required Synchro 8 and 95 th percentile queue lengths were used to analyze and project queue lengths and associated queue storage needs. All projected queue lengths through 236 are less than the queue storage already provided. See Table 2 for a summary of this analysis. INTERSECTION TABLE 2 QUEUE LENGTHS AND ASSOCIATED STORAGE NEEDED EXISTING STORAGE (FT) C. Traffic Signal Warrant 3 Analysis INTERSECTION CONTROL YEAR 216 BACKGOUND TRAFFIC QUEUE LENGTH (FT) 95TH PERCENTILE AM PM YEAR 218 BACKGROUND TRAFFIC QUEUE LENGTH (FT) 95TH PERCENTILE AM PM YEAR 236 BACKGROUND TRAFFIC QUEUE LENGTH (FT) 95TH PERCENTILE AM PM YEAR 218 TOTAL TRAFFIC QUEUE LENGTH (FT) 95TH PERCENTILE AM YEAR 236 TOTAL TRAFFIC QUEUE LENGTH (FT) 95TH PERCENTILE PM AM PM 1. E 128TH AVE / SOUTH ACCESS DRIVEWAY TWSC a EB L b SB R NOTES: 1 Vehicle Length = 25 feet When evaluating future traffic conditions, the only Traffic Signal Warrant that can be evaluated is Warrant 3 (Peak Hour Volume) since only peak-hour volumes are projected for a new land use. The MUTCD states that Warrant 3 should only be used for analyzing intersections that have unusual traffic characteristics such as when large numbers of vehicles are discharged over a short time frame. This condition does not appear to be met at the study intersection. However, traffic signal warrant analysis using Warrant 3 for the intersection of E 128 th Ave and South Access Driveway is included in this analysis as a guide for the potential signalization in the future, not as a recommendation today. Based on existing traffic volumes, Traffic Signal Warrant 3 is met in 216. See Traffic Signal Warrant 3 worksheets in Appendix C. Page 5 of 6

31 Warrant 3: Peak Hour 1: South Driveway & E 128th Ave Hour Warranted / Unwarranted Major Street Total of both approaches (VPH) Minor Street Highest volume approach (VPH) : Federal /8/216 You created this PDF from an application that is not licensed to print to novapdf printer (