MEMORANDUM - High Level Traffic Review (Watt Consulting Group)
Traffic review memorandum analyzing the impact of the proposed development on the local road network.
MEMORANDUM
To: Heather Spinney – Praxis Architects Inc. From: Nadine King, P.Eng., PTOE Our File #: 2342.B01 Project: 231 Heddle Ave Development Date: February 14, 2018 RE: High Level Traffic Review
1.0 INTRODUCTION
A nine unit townhouse development is proposed for 231 Heddle Avenue in View Royal. This memo reviews the existing traffic volumes on Heddle Road and Helmcken Road and projects the expected traffic that will be created by the new development. A review of road classification and cross section will be undertake to determine if the road can handle the additional traffic.
2.0 EXISTING TRAFFIC VOLUMES
Heddle Avenue is a dead-end road located south of Island Highway. The north end of Heddle Avenue does not connect to Island Highway. Access to Island Highway is via Prince Robert Drive and View Royal Avenue to Helmcken Road.
AM and PM traffic volume data was collected for the intersections of Heddle Avenue/Prince Robert Drive and Helmcken Road/Island Highway to determine traffic volumes in the area.
North of Prince Robert Drive, on Heddle Avenue, the AM traffic volume is 14 vehicles per hour (vph) and the PM volumes is 15 vph. South of Prince Robert Drive, on Heddle Avenue, the AM traffic volumes is 40 vph and the PM is 28 vph. On Helmcken Road, south of Island Highway the AM volume is 161 vph and the PM volume is 112 vph. Based on this information the AM peak hour volumes are slightly higher than the PM peak hour.
Daily volumes on Heddle Avenue, north of Prince Robert Drive is 100 vehicles per day (vpd). South of Prince Robert Drive the daily traffic volume is 280 vpd. Volumes on Helmcken Road, south of Island Highway are estimated at 1,120 vpd. Roadways with volumes below 400 vpd are classified as low volume roads.
3.0 DEVELOPMENT TRAFFIC
The proposed development will be located north of Prince Robert Drive. The ITE Trip Generation Manual (10th Edition) was used to generate the traffic for the proposed development. See Table 1 for the development trips
TABLE 1: DEVELOPMENT TRIP GENERATION
| Land Use | Units | Trip Rate | Total Trips |
|---|---|---|---|
| AM Peak Hour | |||
| Multi-Family Low Rise | 9 | 0.46 / unit | 4 |
| Total | 4 | ||
| PM Peak Hour | |||
| Multi-Family Low Rise | 9 | 0.56 / unit | 5 |
| Total | 5 | ||
| Daily | |||
| Multi-Family Low Rise | 9 | 7.32 / unit | 66 |
| Total | 66 |
During the peak periods of the day the proposed development will add 5 vehicles per hour to the network. This equates to one vehicle every 12 minutes.
4.0 ROAD CLASSIFICATION
Heddle Avenue is classified as a local road, while View Royal Avenue and Helmcken Road are classified as collector roads. However, the section of Heddle Avenue, north of Prince Robert Drive acts like a public laneway with low volumes and narrow asphalt (10m at the intersection that narrows to 4m at 235 Heddle Avenue). Local roadways have traffic volumes up to 1,000 vph and operating speeds in the range of 20km/h to 50km/h. Collector roadways carry volumes from 1,000 to 12,000 vpd, but typically below 5,000 vpd.
Based on the existing daily traffic volumes each of the roadways is operating the same as their classification. The additional of the development traffic does not change the road classifications for Heddle Avenue, View Royal Avenue, and Helmcken Road.
5.0 ROAD CROSS SECTION
The existing road cross section, on Heddle Road, north of 239 Heddle Avenue, is approximately 4.0m of asphalt with no centreline or shoulders. A grassed ditch is provided on the west side of the roadway. South of 239 Heddle Avenue the asphalt abruptly widens to 10m. The widening is on the east side and extends to the property line of 239 Heddle Avenue. No lane markings are provided on this section of Heddle Avenue. South of Prince Robert Drive the width of the roadway is 5.7-6.0m of asphalt.
It is recommended that Heddle Avenue, north of 239 Heddle Avenue be widened to 6.0m to accommodate the development traffic and facilitate emergency vehicle (fire truck) access to 231 Heddle Avenue. This widening will impact the concrete driveway (that extends beyond their property line) for 235 Heddle Avenue as well as the paved parking area currently provided in front of the house (also on the public right of way). In addition a portion of the hedge between 239 and 235 Heddle Avenue will need to be removed (hedge extends approximately 8.7m beyond property line).
6.0 CONCLUSIONS
The addition of the development adds less than 5 vehicles per hour to Heddle Avenue. The addition of this traffic has no impact on the surrounding road networks function or operation. However, Heddle Avenue, north of 239 Heddle Avenue should be widened to 6.0m to accommodate the development and emergency services as well as a better aligned road. This widening will impact the hedge, concrete driveway, and paved on-street parking stall on 235 Heddle Avenue. These elements are well within (approximately 8.7m) the public right-of-way for Heddle Avenue.
Sincerely,
Watt Consulting Group
Nadine King, P.Eng., PTOE Senior Transportation Engineer
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