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Home My WebLink AboutZMA202100013 Correspondence 2022-07-06 (4)• • • • S S � s 1001 Boulders Parkway TIMMONS GROUP Suite300 YOUR VISION ACHIEVED THROUGH OURS. Richmond, VA23225 To: Kevin McDermott, PE (Albemarle) and Doug McAvoy, Jr., PE (VDOT) From: Steve Schmidt, PE, PTOE (Timmons Group) RE: Southwood Phase 2 TIA Response to County/VDOT Comments Date: May 27, 2022 P 804.200.6500 F 804.560.1016 www.timmons.com Timmons Group submitted a revised Traffic Impact Analysis (TIA) on February 21, 2022 for the Southwood Phase 2 project located in Albemarle County, Virginia. The project is County case number ZMA2021- 00013. The Virginia Department of Transportation (VDOT) issued comments on the revised TIA on March 28, 2022. Timmons Group (TG) has reviewed VDOT's comments (in bold below) and prepared the responses below. As a result of the comments/responses, no updates to the TIA are required. Our responses to VDOT comments are as follows: VDOT Comments 1. Comments from District Traffic Engineering: a. The agency is still on SIDRA version Sand as such cannot analyze submitted SIDRA 9 files. Please include printouts of the options and Roundabout data tabs. TG Response: The printouts of the options and roundabout data tabs are attached to this response to comments. b. Besides being conservative, is there another reason internal capture was not factored? TG Response: Internal capture was not factored/considered for several reasons. As VDOT notes, one reason was to provide a conservative, or worst -case analysis. Additionally, at the time of the analysis, there were no identified users or types of office/retail available and any internal capture between the residential units and office/retail uses would be speculative. c. Pages 39, 40 and 75: As the loth Edition of the ITE Trip Generation manual was referenced on the scoping document, is there a reason why the 11th Edition was used instead for this submission (page 40)? In addition, the previous submission was also based on the loth Edition. To facilitate a better estimation of the "net CIVIL ENGINEERING I ENVIRONMENTAL I SURVEYING I GIS I LANDSCAPE ARCHITECTURE I CONSTRUCTION SERVICES Southwood Phase 2 Response to Comments May 27, 2022 Page 2 of 3 increase" in development, the 10the Edition of the ITE Trip Generation manual should be used to estimate the trips from Phase 2. TG Response: The 11" edition of Trip Generation was used in the revised analysis as it contained significant updates to the 10`h edition based off of additional studies. The 1th edition is more statistically relevant and provides a more accurate estimate of the trip generation. For example, in the 10`h edition, the mobile home park (Land Use Code 240) rates/equations were based off of only 1 study. The 11t' edition updated the mobile home park rates/equations to include data from 13 studies. Other land use codes had similar updates. Therefore, the trip generation contained in the revised analysis (using the 11t') edition is more accurate and provides a better estimate of site traffic. d. Pages 39 and 40: Pease clarify the Mobile Home Park status and also explain why the "Existing Residential Development —To be Removed" were not estimated as occupied dwelling units? TG Response: The existing mobile home park is still in use and residents occupy the units. The "Existing Residential Development — To be Removed" trips were calculated based on the number of dwelling units as that represents the entire traffic potential of the existing use. This approach is consistent with VDOT guidelines on estimating traffic for redevelopment sites. Further, ITE Trip Generation for this land use code (240) only contains data for "dwelling units" and not "occupied dwelling units". e. Pages 42: Please include missing distributions at Hickory Street intersection. TG Response: Page 42 (Figure 5-1) shows the residential trip distribution for the site. Per the discussion on page 41, it was assumed that 80% of residential site traffic will use the Old Lynchburg Road/Hickory Street intersection to access the site. The remaining 20% of residential traffic will access the site via Hickory Street (north) to Oak Hill Road to Stagecoach Road. This traffic appears on Figure 5-1 at the 5" Street Extended/Stagecoach Road intersection. Southwood Phase 2 Response to Comments May 27, 2022 Page 3 of 3 Per County comments on the initial TIA submission, no analysis was required along Hickory Street. f. Page 52, Figure 7-1: "2036 Existing" could be better revised as "2036 No Build." TG Response: Figure 7-1 (page 52) is titled "2036 Existing+ Growth Peak Hour Volumes". As discussed in Section 7.1 (page 49 of the pdf), this figure contains the summation of the existing traffic volumes plus 1%annual growth over the 15 year period from 2021 to 2036. g. Pages 113 and 125: Please code the Synchro models per the signal timing data. TG Response: Page 113 shows the basic signal timing data for the 5`h Street Extended/1- 64 Eastbound ramp intersection. TG acknowledges that in the PM Synchro model, the vehicle extension for Phases 2/6 should be coded as 3.5 seconds and not the 3.0 seconds in the model. Page 125 shows the basic signal timing data for the 5tn Street Extended/1-64 Westbound ramp intersection. TG acknowledges that in both the AM and PM models, the minimum green time for Phase 4 should be 8.0 seconds and not the 10.0 seconds in the model and that for Phase 2, the minimum green time should be 10.0 seconds and not the 8.0 seconds in the model. It is noted that these minimum green times do not materially impact the analysis as the signal is running time of day plans during both peak hours where each phase is receiving more than the minimum green time. Both of these intersections are over capacity and have been identified by VDOT for future study/improvement. The changes in the base signal timings noted above will not materially impact the results of the analysis or the conclusions of the traffic study. 2. Note that the final plan must show conformance with the VDOT Road Design Manual Appendices B(1) and F, as well as any other applicable standards, regulations or other requirements. TG Response: Noted. ® ROUNDABOUTS - 5th Street @ Old Lynchburg Road - 2030 Background (Site Folder: General) Options I Roundabout Data Roundabout Model Options Roundabout Capacity Model ,, SIDRA Standard O US HCM 6 (1 US HCM 2010 Roundabout Level of Service (LOS) Method Q SIDRA Roundabout LOS 'h Same as Signalised Intersections ej Same as Sign Control Delay Model Exclude Geometric Delay ❑® HCM Delay Formula HCM Roundabout Capacity Model Extension Apply the SIDRA Model for Unbalanced Flow Conditions for HCM 6 Apply the SIDRA Model for Unbalanced Flow Conditions for HCM 2010 Other Roundabout Models FH WA 2000 LU Use Urban Compact Roundabout ❑E HCM 2000 Q NAASRA 196E When you change the Roundabout Capacity Model, the related parameters Roundabout LOS Method, HCM Delay Formula and Exclude Geometric Delay will remain unchanged- This enables the comparison of the effect of the change of roundabout capacity model in terms of the capacity model only while other parameters remain unchanged. However. you can specify any combination of these parameters for the selected Roundabout Capacity Model. Table: Default settings of related parameters involved in changing between the US HCM 6I US HCM 2010 and SIDRA Standard roundabout capacity models Roundabout Capacity Model Related Parameters SIDRA Standard US HCM 6 1 US HCM 2010 Roundabout LOS Method Same as Signalised Intersections Same as Sign Control Unchecked Checked HCM Delay Formula (use Ube SIDRA Standard Delay (use the HCM Delay equation) equation) Exclude Geometric Delay Unchecked Checked (include geometric delay) (exclude geometric delay) Help OK Appty Process Site Options Roundabout Data La Site Display Geometry 1i W I ® ' — E S Current Capacity Model: SIDRA Standard Dialog Tics Number of Girc Lanes Circulating Width Island Diameter Inscribed Diameter 1 20.0 ft 1D0.0 ft Program 2 20.0 ft 100.0 ft Program 2 20.0 ft 100.0 ft Program 1 20.0 ft 10D.0 ft Program Entry Radius 65.0 ft 65.0 ft 65.0 It 65.0 ft EnIFy Angle 30.00 30.00 3D.0 0 30.00 Raindrop Design ❑p 0 M Circulating Transition Line Number of Downstream Circ Lanes ❑0 0 Program Program Program Program SIDRA Standard Roundabout Model Calibration Environment Factor Enky/Circ Flow Adjustment OK Ap* I Process Site Layout x 1N + 50%