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HomeMy WebLinkAboutSUB201900198 Correspondence 2020-01-02SHIMP ENGINEERING, P.C. Design Focused Engineering December 30, 2019 Mr. Adam Moore, P.E. Virginia Department of Transportation 701 VDOT Way Charlottesville, VA 22911 Regarding: Galaxie Farm Subdivision Right & Left Turn Warrant Analysis Mr. Moore, Please find enclosed a left and right -turn warrant analysis Galaxie Farm Subdivision off of Scottsville Rd (Rte. 20) between Avon St (Rte 742) and Thomas Jefferson Parkway (Rte 53). The following items are included with this report: • ITE Trip Generation Summary • Warrant Analysis Exhibit • ITE TripGen AADT Reports Our analysis shows that a right taper is warranted, but neither right nor left turn lanes are warranted for this project. If you have any questions you may contact me at keane@shimp-en ing eering com or by phone at 434-299- 9843. Best Regards, Keane Rucker, ETT Shimp Engineering, P.C. 912 E. High St. Charlottesville, VA 22902 1434.227.5140 1 shimp-engineering.com Galaxie Farm is a proposed 65 unit development on Rte 20 with an entrance located 1700 feet south from Mill Creek Dr/Scottsville Rd intersection. According to VDOT's 2016 Traffic Data, this segment of road has an AADT of 6,300 with a K factor of 0.1007 and Directional factor of 0.7602. This data was used to determine the peak hour volumes along Rte 20. The predominant direction of traffic was assumed to be South towards Scottsville in the evening. Below is the ITE trip generation summary table that was used to determine the PHV right and left turns. Using the direction factor, the number of cars entering was split between left and right turns. The traffic generated from the site was also added into the peak hour volume of Rio Road East. Table 1. ITE trip generation summary table AM PM Use Description ITE Qty In Out Total In Out Total Single Family Housing 210 30 7 20 27 22 12 34 Multifamily Housing (Mid -Rise) 221 35 4 11 15 11 7 18 Total 11 31 42 33 19 52 The information in Table 1 was retrieved the ITE TripGen Web -based App on Dec. 30, 2019. Figures 3 and 4 at the end of this document display original data from this website. Figures 1 & 2. Warrant for left turn treatment (2-lane highway) WARRANTS FOR LEFT TURN LANES ON TWO-LANE HIGHWAYS VPH ADVANCING VOLUME OPPOSING 5% 10% 20% 30% VOLUME LEFT TURNS LEFT TURNS LEFT TURNS LEFT TURNS„ 40•MPH DESIGN SPEED` 800 330 240 180 180 600 410 305 225 200 400 510 380 275 245 200 840 470 350 305 100 720 515 390 340 50•MPH DESIGN SPEED• 800 280 210 165 135 800 350 280 195 170 400 430 320 240 210 200 550 400 300 270 100 815 445 335 295 60-MPH DESIGN SPEED• 170 125 115 800 290 210 270 180 200 140 175 400 365 200 450 330 250 215 100 505 370 275 240 TABLE 3-1 Source: Adapted from 2011 AASHTO Green Book, Chapter 9, Section 9.7.3, Page 9-132, Table 9-23 USE DESIGN SPEED IF AVAILABLE, IF NOT USE LEGAL SPEED LIMIT. OPPW D VOIUIE(WH) --------- ---- ADVAh(M VOLIAIIIlVI'M ISriUIIN VOUNEM" Example: Two-lane highway with 40-MPH operating speed Opposing Volume (VPH) - 600 Advancing Volume (VPH) - 440 Left-Tum Volume (VPH) - 44 or 10% of Advancing Volume With opposing volume (VPH) of 600 and 10% of advancing volume (VPH) making left turns, and advancing volume (VPH) of 305 or more will warrant a left-tum lane. When the Average Running Speed on an existing facility is available, the corresponding Design Speed may be obtained from Appendix A, Section A-1. WARRANT FOR LEFT -TURN STORAGE LANES ON TWO-LANE HIGHWAY 800 700 j 6130 I— LU 500 J D 400 Z 300 8 IL 200 O` D 100 ■.�. ■■■■ ■■r,= ■■II■ ■■11■volume■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■ ■■II■ ■■i■..�.�■■H ■■■■■■■■■■■■■ ■■!■■■■■■■■■■■■■�■■■■■■■■■o■■■■ ■■■■■■■■■■■■■1■■■■■■■■■■■■■■■■■■ ■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■1■ ■ ■ ■■■■■MM:■■■■■■ms 111111i1111111, ■■■■■■■■■■■■■R■■R■■■■■■■■■■■■■■ ■111111Oil1i11i1111111111 i0100r,000 ■■■■■t■ti■■■■■■■■■ ■■■■■Mtl■■■■■■■■■ NEON i■■■■if ■ONI■■■■■■■■■ ti■■■■■tti■■■ a 1 PeakHour Volume■■■■■■■■■■■■■■■!■■■■■■ ■■■1■■■■■■■■■■■■■■■■■■ ■■■■■■■■■■■■■■■■■■■■■■ ■■■■■■■■■■E■i■■ii■■■1■ �rE��t�i��f���1� ■■moon ■■■■■■!■■ ■■■■■■■■1■■■■■■■■■■■t■■■■■�■■■■ • . -, I:=:CIC:I:IIIINEWREENERM::JI 200 400 600 800 1000 VA ADVANCING VOLUME (VPH) Rte 20 has a speed limit of 55 mph at the entrance to the townhomes. The peak left turns into the site occur in the evening, with 8 left turns out of a total of 160 advancing vehicles (the additional turns generated by the site are included in the approach total). These turns make up about 5% of the advancing volume. With an opposing volume of 508 vehicles, a left turn lane is not warranted according to Figures 1 & 2 above. Figure 3. Warrant for right turn treatment (2-lane highway) 120 1cr 00 8 x W so eo 40 20 F-79 100 200 300 400 500 800 700 PHV APPROACH TOTAL, VEHICLES PER HOUR Appropriate Radius required at all Intersections and Entrances (Commercial or Private). IFrFNn PHV - Peak Hour Volume (also Design Hourly Volume equivalent) Adiustment for Right Turns For posted speeds at or under 45 mph, PHV right turns > 40, and PHV total < 300. Adjusted right turns = PHV Right Turns - 20 If PHV is not known use formula: PHV = ADT x K x D K = the percent of AADT occurring in the peak hour D = the percent of traffic in the peak direction of flow Note: An average of 11% for K x D will suffice. When right turn facilities are warranted, see Figure 3-1 for design criteria. FIGURE 3-26 WARRANTS FOR RIGHT TURN TREATMENT (2-LANE HIGHWAY) The evening has the peak hour volume approach total, with 516 vehicles approaching. This total includes 25 vehicles estimated to make right turns into the site. Figure 3 above shows that a right turn taper is warranted for the Galaxie Farm Subdivision. Per VDOT App. F Figure 3-1, for an urban or rural road with a speed limit of 55 mph, the required taper length is 200'. Figure 3. ITE TripGen PM Peak hour AADT — Single -Family Units /TEThpGen Web -based App A Help ©Justin Shim, Ij 1 Graph Look Up CDData Plot and Equation DATA STATISTICS Land Use: Single -Family Detached Housing (210) CUck. for DATA SOURCE: 80 X X X'�, cre Celails Independent Variable: Dwelling Units Trip Generation Manual, 10th Ed ' X X Time Period: SEARCH By LAND U SE CODE: X X Weekday 210 Q 60 X X PM Peak Hour of Generator ' X X SetBrlglLocation: LAND USE CATEGORY: 40 XX X --------- � xX X General Urban/Suburban Trip Type: Vehicle (200-299) Residential X X X LAND USE: 20i n F � Number of Studies: 165 Avg. Num. of Dwelling Units: 210-Single-Family Detached Housing INDEPENDENT VARIABLE 1N): 0 217 Average Rate: 1,00 Dwelling Units TIME PERIOD: -20 Range of Rates: 0.49 -2.98 Standard Deviation: Weekday, PM Peak Hour of Generator L71 SETTING/LOCATN)N: -60 -50 0 X = Number of Dwelling Units 50 100 031 Fitted Curve Equation: Lh(T) = 0.94 Lri - 0.34 General Urban/Suburban TRIP TYPE: Reset Zoom I Restore Ra: 0.92 Directional Distribution: Vehicle ENTER N VALUE TO CALCULATE TRIPS: X Study Site Fitted Curve --- Average Rate 64%entering, 36%exiting 30 Calculate lculated Trip Ends: Average Rate: 30 (total). 19 (Entry), 11 (E)d0 Filled Curve: 34 (Total), 22 (Entry), 12 (Exit) Figure 4. ITE TripGen PM Peak hour AADT — Multi -Family Mid -Rise Units ITEMpGen Web -based App -5 ml Graph Look Up DATA SOURCE: Trip Generation Manual, 10th Ed SEARCH BY LAND USE CODE: 221 O LANDUSECATEGORM (200-299) Residential LAND USE: 221 - Multifamily Housing (Mid--.e) INDEPENDENT VARIABLE (N): Dwelling Units TIME PEW11. Weekday, PM Peak Hour of Generator SETTINWLOCATION: General Urban/Suburban TRIP TYPE: Vehicle ENTER N VALUE TO CALCULATE TMPS: 36 Calculate Data Plot and Equation 40', 30 20 F n r 10 0 0 20 40 60 X - Number of Dwelling Units Reset Zoom Restore X Study Site Fitted Curve 80 --- Average Rat A Help ()Justin Shimp 40 8 Change Password AAccount Settmos � e DATA STATISTICS Land Use: Multifamily Housing (Mid -Rise) (221) Click for more oetaiis Independent Variable: Dwelling Units Time Period: Weekday PM Peak Hour of Generator Seturg/Location: General Urban/Suburban Trip Type: Vehicle Number of Studies: 47 Avg. Num. of Dwelling Units. 211 Average Rate: 041 Range of Rates: 0.09 -1.26 Stndard Deviation: 0,22 100 Fitted Curve Equation: Lr(T) = 0.83 Ln(X) - 0,05 Ra: 0,66 Directional Distribution: 60% entering, 40% exiting Calculated Trip Ends: Average Rate: 14 (Total), 8 (Entry), 6 (Exit) Fitted Curve: 18 (rotl), 11 (Entry), 7 (ExiO