Addendum to Transportation Review Report
Memo assessing the cumulative traffic impact from a nearby mixed-use development on Island Highway and Helmcken Road.
December 14, 2023
Jeffrey Sengara 294 & 296 Eltham Road & 242 Helmcken Road View Royal, Victoria, British Columbia E-mail: budandblues@shaw.ca
RE: Addendum to Our Transportation Review Report for Residential Development, 20-Unit Townhouse, View Royal, British Columbia. Updated December 1, 2023.
ISSUE: Assessing the Impact of the Mixed Use, Commercial & Residential Development Located at Northeastern Quadrant of Island Highway and Helmcken Road Intersection on Eltham Road and Helmcken Road Intersection.
Dear Mr. Sengara:
Addoz Engineering Inc. prepared this addendum to be part of the completed Transportation Review Report for Residential Development, 20-Unit Townhouse, View Royal, British Columbia. Updated December 1, 2023. The purpose of this addendum is to assess the impact of the Commercial & Residential Development Located at Northeastern Quadrant of Island Highway and Helmcken Road Intersection on Eltham Road and Helmcken Road Intersection. We utilized the needed data for this purpose form the TIA that was completed for the Island Highway development dated July 9, 2020 and Revised on October 8, 2020.
Figure 1 presents the Mixed-Use Island Highway development's site generated traffic at the Helmcken Road and Eltham Road intersection. Note that these numbers were taken from the TIA report completed for this project on Figure 9 of that report. These traffic volumes were then added to the 20-Unit Development's Post Development peak hour volumes presented on Figure 2; this is basically Figure 6 in the Transportation Review Report. The resulted total post development traffic at Helmcken Road and Eltham Road intersection are presented on Figure 3.
Capacity Analysis for Post Development Traffic Conditions
LOS and capacity analyses results for the Post Development, Opening, traffic conditions (with site development generated traffic and Island Hwy Development's trips) for study intersection are presented in Table 1. Copies of the HCM Synchro capacity analysis reports are included in Attachment #1.
Table 1: Capacity Analysis for Post Development Traffic Conditions
| Unsignalized Intersection | App. | AM Peak Hour 95%tile Queue (VEH) | AM Peak Hour V/C(a) Ratio | AM Peak Hour Delay "Sec" | AM Peak Hour LOS | PM Peak Hour 95%tile Queue (VEH) | PM Peak Hour V/C(a) Ratio | PM Peak Hour Delay "Sec" | PM Peak Hour LOS |
|---|---|---|---|---|---|---|---|---|---|
| Helmcken Road and Eltham Road | WB | 1.4 | 0.060 | 11.8 | B | 1.4 | 0.055 | 11.5 | B |
| NB | - | - | 0.0 | A | - | - | 0.0 | A | |
| SBL | 0.0 | 0.004 | 7.9 | A | 0.0 | 0.015 | 7.9 | A |
A review of Table 1 indicates that the Helmcken Road and Eltham Road intersection would continue to operate at acceptable levels of service including the stop sign controlled approaches without any issues, during both the AM and PM peak hours. Therefore, no mitigation would be required under the Post Development traffic conditions, with the Mixed-Use Island Highway development's site generated traffic.
Left Turn Requirement
The volume warrants are typically based on the capacity analysis. Since the completed Synchro capacity analysis for the Post Development conditions did not show any operational deficiency or unacceptable levels of service, the installation of a left-turn only lane in the SB or in the WB are NOT warranted based on volume warrants. Refer to Table 1 above that presents the capacity analyses results for the Post Development conditions. The SB left-turn would operate at LOS "A" and the WB approach would operate at LOS "B", with almost no queues forming. Therefore, the installation of a left-turn only lane in the SB or in the WB are NOT warranted.
Based on the completed analyses the Mixed-Use Island Highway development's site generated traffic would not negatively impact the Helmcken Road and Eltham Road intersection. Please do not hesitate to contact us shall you have any questions or comments.
Sincerely Yours,
ADDOZ ENGINEERING INC
Prepared by: Emad Alsaidi, PhD, PEng, PE Direct Phone: (587) 703-5222 or (587) 703-9321 E-mail: ealsaidi@addozeng.ca
Attachment #1
Copies of the Synchro Capacity Analysis Results
Document Images
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