Northfield/Boxwood Intersection Upgrade Transportation ... · We are pleased to present our report on the Transportation Analysis for this project. This report provides a planning

Rosstown Connector

Boxwood Connector

Northfield RoadB

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Northfield/BoxwoodIntersection Upgrade

rj+associates

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Transportation Engineering and Planning

Roads, Transit, Bicycles, Pedestrians

Northfield/Boxwood Intersection Upgrade

Transportation Engineering Report

for AndersonCivil Consultants

City of Nanaimo

July 2010

Page 1

Richard James & Associates,4456 Craig Court,

Victoria, BC,V8N 5W3

Tel: 250-721-5897Cell: 250-514-1188Fax: 250-721-5938

E-Mail: [email protected]

Dear Sirs, Re: Northfield/Boxwood Intersection Upgrade We are pleased to present our report on the Transportation Analysis for this project. This report provides a planning level review of the Transportation Engineering issues for the project for the 2010 and 2024 design years.

Mr. Douglas Anderson, P. Eng, AndersonCivil Consultants, 206b -335 Wesley Street, Nanaimo, BC, V9R 2T5 Mr. Gordon Foy, P. Eng., Traffic and Transportation Engineer Engineering and Public Works, City of Nanaimo,

Date: July 9th 2010 Project Number: Northfield

Yours truly,

Richard A James, P. Eng., PTOE


Index Summary report ...................................................................................................................................................1 Introduction..........................................................................................................................................................2 Planning background ...........................................................................................................................................2 Review of the conceptual network plan...............................................................................................................3 Review of future travel demand projections ........................................................................................................3 Review of pedestrian and cyclist facilities...........................................................................................................4 Identification of outstanding issues......................................................................................................................4 Traffic analysis.....................................................................................................................................................6

1. Traffic analysis background and discussion ............................................................................................6 2. 2010 .........................................................................................................................................................6

a. 2010 A.M. Peak ...................................................................................................................................7 b. 2010 P.M. Peak ....................................................................................................................................8

3. 2024 .......................................................................................................................................................10 a. 2024 A.M. Peak .................................................................................................................................11 b. 2024 P.M. Peak ..................................................................................................................................12

4. Boxwood Roundabout ...........................................................................................................................14 5. Sensitivity Analysis ...............................................................................................................................14 6. Turn lane lengths recommendations ......................................................................................................15 7. Signal timing plans ................................................................................................................................16

Transportation Analysis Appendices .................................................................................................................17 1. Interim Report on the Concept Plan...................................................................................................17 2. Trip Generation Rates ........................................................................................................................17 3. Trip Generation and Assignment .......................................................................................................17 4. Traffic Operations Observations ........................................................................................................17 5. Volume Adjustments..........................................................................................................................17 6. Turn Lane Configuration and Signal Phasing....................................................................................17 7. Synchro Timing Plans........................................................................................................................17

Addendum: issued Aug 16th 2010

1 Page 10, sentence added re generated traffic (penultimate paragraph) 2 Figures 2 and 3, link volumes added.


Northfield/Boxwood Intersection Upgrade Page 1 of 17

Transportation Engineering Summary report This report reviews the current operation of the Northfield/Boxwood and Northfield/Bowen intersections and projects future traffic operations with the construction of the proposed Boxwood connector as shown on Figure 1 – Key Plan. The connector runs from the Northfield/Boxwood intersection to a new intersection with Bowen Road in the vicinity of the Beban Park south access; it includes the relocation of Rosstown Road to connect to the new route. The new route would serve two purposes:

1. Divert traffic from the current Northfield/Bowen intersection to the new route with the objective of reallocating available phase times at Northfield/Bowen to better accommodate north/south traffic on Bowen Road and east/west traffic on Northfield Road

2. Provide for managed access to undeveloped land in the north-west quadrant of the Northfield/Bowen intersection

The initial review of the project (see Appendix 1) indicated that it was likely that the new connector would achieve the primary objective of rerouting traffic providing that a number of traffic management and information measures were undertaken. These measures are:

1. Prior to opening, provide information through public media of the function and intended operation of the project.

2. Provide clear and understandable advance direction signing sufficiently far in advance of the two new intersections to ensure that drivers are able to understand and act upon the signing.

3. Optimise signal timing to minimise delay to traffic diverted to the new link whilst retaining good operation on Bowen Road as a major north/south corridor through both the Bowen/Boxwood and Northfield/Bowen intersections.

4. Monitor operations to measure the effectiveness of the new link. We recommend that the project be staged with initial construction of only the Northfield/Boxwood intersection without the new connector or changes to the Northfield/Bowen intersection. A second stage would be construction of the new Boxwood link including realignment of Rosstown Road and potentially access to Beban Mall via the Beban Park access. After monitoring operations under this configuration, together with any fine-tuning of signal timing plans to achieve the desired rerouting of traffic, base the design for improvements to the Northfield/Bowen intersection on the actual volumes measured (particularly for the eastbound left turn). We make several observations regarding the detailed design of the new link and modifications to the Northfield Road access that are summarised on page 4 of our report.


Introduction The traffic engineering component of the project includes four significant steps:

1. Review of the city's justification for the project including the conceptual network plan and travel demand projections.

2. Conceptual review of the bicycle and pedestrian facilities and engineering issues related to traffic operations.

3. Detailed traffic operations analysis. 4. Design recommendations including turn lane lengths, laning requirements, bicycle and pedestrian

facilities, protection of future right of way and "opening day" signal timing plans. This work was carried out by Richard James and Associates, and DPL Consulting. The steps are described in the following paragraphs. Planning background The Bowen/Northfield intersection is one of the more congested locations in the Bowen Road corridor, which is a major north/south artery parallel to Highway 19 (Nanaimo Parkway) and the Highway 1/19A corridor. The background to the project is described in city produced material that was reviewed at the beginning of the project. The two key goals are:

1. Provide relief to the congested Bowen/Northfield intersection 2. Provide a local road system to service adjacent land in the north-west quadrant of the Bowen/

Northfield intersection The functional concept is to divert eastbound to northbound left turn traffic (and the opposite movement) at the Bowen/Northfield intersection to use a new link extending Boxwood from Northfield north-easterly to Bowen Road in the vicinity of the current Beban Park south access. Rosstown Road would be relocated to connect to this new link and extended across it. This new link will also service the adjacent land use. The Beban Mall access configuration may also be altered as a consequence of this project and the general implementation of access management along Bowen Road. The concept is to provide a new access off the Beban Park access road (as discussed below). In addition, the city may consider at some time in the future facilitating the diversion of some northbound left turn traffic (and the opposite movement) at the Bowen/Northfield intersection to use Meredith and then Boxwood to reach Northfield. Analysis of this option was excluded from the project. For the study, the city provided conceptual land use data that envisages a mix of commercial and residential development. The traffic impact of this proposed development is discussed in our review of the future travel demand projections.

Scale: NTS

Key Plan

Date: July 2010 Figure 1 Rev

Rosstown Connector

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Northfield/Boxwood City of Nanaimo


Review of the conceptual network plan In general we find that the conceptual network plan is a reasonable concept to address the two key goals that were identified by the city. The proposed new roadway serves two functions and care needs to be taken to achieve an acceptable balance between them. Since the purpose of the link is primarily to carry "through" traffic, it is important to ensure that traffic using this link suffers less total delay than it would if it was routed through the Bowen/Northfield intersection. To achieve this it is desirable that direct access to property be limited and be provided off local streets connected to Boxwood. It is preferable that all access be directed to Northfield and Bowen using Boxwood with no direct access to Northfield or Bowen Roads. The proposed intersection configurations are generally acceptable and are discussed in more detail in our discussion of outstanding issues and in our recommendations on signal timing plans and laning. The proposed bicycle and pedestrian facilities appear to be reasonable and should well serve and encourage potential demand by both area residents and regional users accessing Beban Park. Further comments are made in our review of these facilities below. Our interim report on the concept plan (prepared prior to the completion of our full analysis) is attached as Appendix 1. Review of future travel demand projections The city provided a comprehensive trip generation and reassignment spreadsheet that initially produced only 2014 and 2024 p.m. peak volume projections from 2009 traffic counts. This was subsequently updated by the city to include the a.m. peak and noon periods, and to use the new 2010 traffic counts as the base. These counts are discussed in the Traffic Analysis section. The initial model also used ITE Trip Generation Handbook 5th edition rates that were updated to 8th edition with no significant changes. The model carries out the calculations using a macro and is based on routing rules provided by the user, trip generation rates for new development, and existing traffic counts. The city does not have a comprehensive database of historic traffic volumes or a regional transportation model. This analysis therefore relies on an estimate of regional traffic growth provided by city staff. These assumed growth rates are 1.5% for the first 10 years to 2024 and then at 2.5% for the subsequent ten-year period to 2024. These values appear to be within a reasonable range for regional traffic growth. However, capacity of the system may limit peak period volumes (flow rate). We reviewed the model parameters, including trip generation rates, the general assumptions regarding routing, and the percentage assignment of traffic from origins to the various destinations and entry/exit points and clarified these with city staff. The values used appear to reasonably represent those likely to occur at some time in the future. All these parameters are dependent on many variables and the values used are only estimates of an actual value that may occur in the future. Our sensitivity analysis addresses the impact of changes in these values. Our comments on the Trip Generation Rates are attached as Appendix 2. The routing parameters include those appropriate for traffic generated by the new developments included in the model, the reassignment of existing traffic due to changes in access provision (i.e. Beban Mall) as well as modelling the assumed change in traffic volumes as a result of reassigning turning traffic away from the Bowen/Northfield intersection.


This reassignment of traffic from the Bowen/Northfield intersection is key to the objective of the project. However, the amount of traffic that is diverted cannot be rigorously predetermined by analysis; this is addressed further in the Sensitivity Analysis section of this report. The model uses assumed values that are discussed in our sensitivity analysis. Our comments on the Trip Assignment are attached as Appendix 3. Review of pedestrian and cyclist facilities The city has provided drawings outlining the network facilities to be provided for pedestrians and cyclists along the proposed Boxwood connector. The facilities shown generally meet minimum standards and would be considered adequate, but there are design features that may make it somewhat more difficult for pedestrians and cyclists to make certain basic manoeuvres without perceived danger. The existence of two right-turn lanes at the Northfield/Boxwood intersection: one on Boxwood southbound to westbound, the other on Northfield eastbound to southbound creates a potential crossing problem for pedestrians and cyclists. The crosswalk between the curb and island is “uncontrolled” which may increase conflicts with pedestrians. These turn lanes also create a potential problem for cyclists as drivers may not come to a complete stop before entering the cross-street flow. This increases collision risk for straight through cyclists. In addition, motorists merging into traffic will often look too far back to detect cyclists who have already entered the intersection. While these concerns are noted, the design conforms to normal practice at this time. Identification of outstanding issues During the course of the project we identified a number of outstanding issues that should be addressed by city staff prior to the construction of the Boxwood connection. These include:

1. Laning at the Northfield/Boxwood intersection - at some future time a single left turn lane may become overloaded in which case a decision will have to be made to either:

a. Retain a single left turn lane, extended to accommodate additional queuing, and not widen Boxwood to 2 lanes eastbound, or,

b. Implement either a left turn plus left/through shared lane with split phase timing, or, dual left turn lanes with normal timing and widen Boxwood to 2 lanes eastbound

If the decision is made to widen Boxwood to 2 lanes eastbound, then it is essential that the added lane extend far enough that there is sufficient distance for safe and effective merging if the lane is to be dropped, or, the additional lane is continued through to the Boxwood/Bowen intersection. Given the limited distance to the roundabout at Rosstown Road and the curved road alignment, it appears that the most effective solution to ensure that both left turn lanes are fully loaded is to continue the added lane through to Bowen Road.

2. Laning at the Boxwood/Bowen intersection - the city's configuration for this intersection shows an exclusive left turn plus a shared left/through lane that requires split-phase timing. Whilst this is feasible, the Bowen corridor is very heavily loaded and any reduction in cross-street phase time will benefit flow on Bowen. Consideration should be given to using two exclusive left turn lanes with a shared through/right turn lane. This decision is also related to the issue discussed above where an additional left turn may be required on Northfield Road.


3. On-street parking - the initial concept presented to us by city staff includes potential for on-street parking on both Northfield Road and the Boxwood connection. We would caution that on-street parking on the major arterial poses significant safety and capacity issues even if it is for a limited time periods during the day. Parking in an additional parking only lane that is not part of the through traffic system does reduce the impact but does not eliminate it entirely. It is normal practice on streets, such as Northfield, that are major arterials, to prohibit parking at all times of the day. In addition to the concern with safety and capacity both facilities are proposed to have raised medians. With only one lane available for traffic, that lane will be blocked in the case of a collision or vehicle breakdown that effectively blocks the road in that direction.

4. Beban Park access – the city's proposal includes eliminating the southbound left turn off Bowen Road into the Beban Mall and providing a new access to the Mall from the Beban Park access road; this becomes a new four-legged, all turns, intersection with Bowen Road and the Boxwood connector. The distance between the Boxwood/Bowen intersection and the proposed Mall access is approximately 50 meters. This does not provide adequate clearance for lane selection and queue storage. This is an issue during normal mall operations but will be a much more significant issue if there are significant events at Beban Park during Mall operating hours. The location of the proposed Mall access should be carefully reviewed and the possibility of moving it farther east examined. It is accepted that this may only be feasible should substantial redevelopment of the Mall property occur nevertheless the potential for this should be preserved. Similarly, the access to the Tourist Information Centre adjacent to Bowen Road should be closed with all access taken from the access further north on the internal road system.

5. Northfield laneway at Boxwood - review of the traffic projections for the Northfield/Boxwood

intersection indicates that under the analysed scenario (no Meredith diversion) "normal" traffic growth will increase volumes sufficiently that queuing of northbound traffic at the intersection is likely to extend to the proposed location of this laneway on the east side of Boxwood.

The current westbound left turn access from Northfield into the laneway serving the south side of Northfield will be within potential eastbound traffic queues from the Northfield/Bowen intersection. As such, a left turn across traffic queuing for an intersection is problematic and its future retention should be carefully examined. Left turn access into the laneway on Boxwood is critical to removing left turn access across Northfield at the present laneway "mid-block" between Boxwood and Bowen. Providing a left turn slot for this traffic to prevent obstruction of through traffic is one possibility but has not been included in the proposed design. This would effectively result in a four lane cross-section for this segment of Boxwood (one turn lane plus one through lane in each direction).

6. Diversion of traffic at Meredith - the concept presented by the city included reference to a potential

future diversion of northbound to westbound traffic to use Meredith and Boxwood. Analysis of this option was excluded from the project; however, we can draw some conclusions from our analysis.

Review of the traffic projections for the Northfield/Boxwood intersection indicates that with a significant increase in northbound left turning traffic there will be a significant increase in the queue length that will impact access to the proposed laneway servicing the rear of property fronting onto Northfield. The current northbound left turn traffic on Boxwood is 66 vph; the projection for 2024 is approximately 100 vph, the 2024 projection for the northbound left turn on Bowen to Northfield is approximately 425 vph. If half of this traffic was diverted (say 200 vph) the resulting left turn traffic would be of the order of 300 vph with a significant queue and impact on the signal timing plan.


7. Turn Lanes from Northfield eastbound to Boxwood southbound and Boxwood southbound to Northfield westbound – the concept presented by the City increases the crossing distance for pedestrians crossing west-east on Northfield on the north side of the intersection and crossing north-south on the west side of the intersection. The turn lanes present a manoeuvring problem for straight on cyclists crossing the path of merging motorists. However, this design complies with current practice.

Traffic analysis Traffic analysis for this project was carried out using the Synchro (version 7) software package which implements the general procedure as outlined in the Highway Capacity Manual (HCM 2000, Transportation Research Board, Washington, DC) with the addition of the capability of analysing signal progression. The parameters identified and discussed in the report "City of Nanaimo Signal Timing Standard Practices Review" (2005, Creative Transportation Solutions, Port Moody, BC) were reviewed and used in this analysis. 1. Traffic analysis background and discussion

The traffic analysis was based on new intersection turning movement counts taken in February 2010 at the key locations of; Boxwood/Northfield, Bowen/Northfield, and the three access points to the Beban Mall. In addition, seven-day automatic counts were also carried out on Northfield, Bowen, Rosstown and the Beban Park access. The Bowen, Rosstown and Beban Park counts were used to reconstruct turning movements for these two intersections. Saturation flow data for Nanaimo was not available and was not specifically collected during these counts. During the intersection turning movement counts queue lengths at Bowen/Northfield were observed and recorded in general terms. The analysis was carried out using default parameters that appear to provide reasonable results when compared to the observed queue lengths. Our observations of current traffic operations are attached as Appendix 4. Our discussion of the adjustments to the counted volumes is attached as Appendix 5.

2. 2010

The current traffic volumes (2010) are used as a base for comparison with the future projections as well as the volumes to be used to generate "opening day" timing plans based on 2010 volumes for the interim Boxwood/Northfield intersection without the connector to Bowen Road. These traffic volumes are shown on Figure 2. In Tables 1 - 10 below Synchro symbols have been used as follows:

~ volume exceed capacity, queue may be significantly longer # 95th percentile exceeds capacity, acceptable for design m 95th percentile volume is limited by upstream metering

Scale: NTS


Date: June 6 2010 Rev A

Bowen Road

Boxwood C

onnector

Rosstown (Connector)

Northfield Road

123 AM Volumes345 PM Volumes

Boxwood

Revn A: Link volumes added

0 3 18 4 2 11

1 3 676 545 106 73

30 2 16 66 1 26

5 8 484 778 27 17

626 524

516 803

165 463 83 215 694 78

231 247 266 151 129 126

170 498 44 282 780 36

66 99 143 291 43 94

2010 Adjusted Traffic Volumes

Figure 2

393 265

252 484

783 621

518 844

795 1126

711 987

712 1098

635 913

48 93

135 93

8 12

17 21

323 14 61 229 15 72

305 389 665 443 0 101

70 50 20 108 57 31

315 50 525 782 42 28

655 460

882 860

100 711 151 74 1038 154

73 53 404 233 178 174

242 666 60 426 967 50

93 122 198 415 43 114

135 704 82 337 888 82

389 439 59 59 107 82

55 661 40 196 745 40

13 13 88 88 76 76

83 5 1

90

60 26 1

48

24

75

326 340

14

65

39 1

6 33

44 2

2 92

92 2

72

170

270

13

80

2024 Peak Adjusted Traffic Volumes

Figure 3

756 981

6921266

549 580

275 622

364 480

398 316

968 1443

9321326

140 196

56 144

970 933

9181119

334 651

615 437

181 181

177 177

1113 1197

9211307

132 369

278 234

88

158

32

104

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Date: June 6 2010 Rev A

Bowen Road

Boxwood C

onnector

Rosstown (Connector)

Northfield Road

123 AM Volumes345 PM Volumes

Boxwood

Revn A: Link volumes added

0 3 18 4 2 11

1 3 676 545 106 73

30 2 16 66 1 26

5 8 484 778 27 17

626 524

516 803

165 463 83 215 694 78

231 247 266 151 129 126

170 498 44 282 780 36

66 99 143 291 43 94

2010 Adjusted Traffic Volumes

Figure 2

393 265

252 484

783 621

518 844

795 1126

711 987

712 1098

635 913

48 93

135 93

8 12

17 21

323 14 61 229 15 72

305 389 665 443 0 101

70 50 20 108 57 31

315 50 525 782 42 28

655 460

882 860

100 711 151 74 1038 154

73 53 404 233 178 174

242 666 60 426 967 50

93 122 198 415 43 114

135 704 82 337 888 82

389 439 59 59 107 82

55 661 40 196 745 40

13 13 88 88 76 76

83 5 1

90

60 26 1

48

24

75

326 340

14

65

39 1

6 33

44 2

2 92

92 2

72

170

270

13

80

2024 Peak Adjusted Traffic Volumes

Figure 3

756 981

6921266

549 580

275 622

364 480

398 316

968 1443

9321326

140 196

56 144

970 933

9181119

334 651

615 437

181 181

177 177

1113 1197

9211307

132 369

278 234

88

158

32

104


a. 2010 A.M. Peak

Table 1 Northfield and Boxwood 2010 AM Northfield/Boxwood EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations 1 1> 0 1 1> 0 1 1> 0 0 <1> 0 Volume (vph) 1 676 106 27 484 5 30 2 16 18 3 0 Total Split (sec) 74.0 74.0 0.0 74.0 74.0 0.0 26.0 26.0 0.0 26.0 26.0 0.0 Total Split (%) 74.0% 74.0% 0.0% 74.0% 74.0% 0.0% 26.0% 26.0% 0.0% 26.0% 26.0% 0.0% Maximum Green (sec) 68.0 68.0 68.0 68.0 20.0 20.0 20.0 20.0 v/c Ratio 0.00 0.55 0.06 0.34 0.23 0.10 0.16 Control Delay 4.0 5.6 0.6 0.7 42.4 18.6 40.4 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay 4.0 5.6 0.6 0.7 42.4 18.6 40.4 LOS A A A A D B D Approach Delay 5.6 0.7 33.7 40.4 Approach LOS A A C D Queue Length 50th (meters) 0.0 44.4 0.1 1.9 6.0 0.4 4.2 Queue Length 95th (meters) 0.5 113.4 m0.3 3.7 13.7 6.3 10.5

This analysis shows the ability of the intersection to carry traffic if this intersection was signalised today. All movements on Northfield would operate at LoS A, while Boxwood movements would operate at LoS B or D. This is typical of low volume signalised side streets. The timing plan could be adjusted to improve side street LoS if desired, but with some penalty to Northfield operations. See also the discussion on page 9.

Table 2 Northfield and Bowen 2010 AM Northfield/Bowen EBL EBT EBR WBL WBT WBR SBL SBT SBR NBL NBT NBR Lane Configurations 0 <2> 0 0 <2> 0 1 2> 0 1 2> Volume (vph) 231 266 129 43 143 66 83 463 165 170 498 44 Total Split (sec) 29 29 25.8 25.8 12.2 30.2 15 33 Total Split (%) 29.0% 29.0% 25.8% 25.8% 12.2% 30.2% 15.0% 33.0%Maximum Green (sec) 22.8 22.8 19.6 19.6 6.1 24.4 8.8 26.8 v/c Ratio 0.92 0.62 0.3 0.76 0.63 0.67 Control Delay 49.5 38.5 20.7 37.7 29.7 34.9 Queue Delay 0 0 0 0 0 0 Total Delay 49.5 38.5 20.7 37.7 29.7 34.9 LOS D D C D C C Approach Delay 49.5 38.5 35.7 33.7 Approach LOS D D D C Queue Length 50th (meters) 71.6 29.3 9.9 59.5 22.5 59.7 Queue Length 95th (meters) #96.2 31.3 20.8 80.5 #46.1 82.2


This analysis shows the potential level of service if signal operations were optimised at this currently signalised intersection. Current operations may be somewhat different if the timing plan is not optimised. All Northfield movements operate at a theoretical LoS D. All Bowen movements operate at LoS C except the S/B Through at LoS D. Queue blocking issues discussed alter the perception of operation. b. 2010 P.M. Peak Table 3 Northfield and Boxwood 2010 PM Northfield/Boxwood EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations 1 1> 0 1 1> 0 1 1> 0 0 <1> 0 Volume (vph) 3 545 73 17 778 8 66 1 26 11 2 4 Total Split (sec) 92.0 92.0 0.0 92.0 92.0 0.0 28.0 28.0 0.0 28.0 28.0 0.0 Total Split (%) 76.7% 76.7% 0.0% 76.7% 76.7% 0.0% 23.3% 23.3% 0.0% 23.3% 23.3% 0.0% Maximum Green (sec) 86.0 86.0 86.0 86.0 22.0 22.0 22.0 22.0 v/c Ratio 0.01 0.45 0.03 0.57 0.49 0.15 0.11 Control Delay 3.3 4.8 0.1 1.1 60.2 17.7 39.6 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay 3.3 4.8 0.1 1.1 60.2 17.7 39.6 LOS A A A A E B D Approach Delay 4.8 1.0 48.0 39.6 Approach LOS A A D D Queue Length 50th (meters) 0.1 38.1 0.0 1.7 16.2 0.2 3.0 Queue Length 95th (meters) 0.9 70.7 m0.1 m2.2 29.7 8.7 9.5

This analysis shows the ability of the intersection to carry traffic if this intersection was signalised today. All movements on Northfield would operate at LoS A”, while Boxwood movements would operate at LoS B, D or E. This is typical of low volume signalised side streets. The timing plan could be adjusted to improve side street LoS if desired, but with some penalty to Northfield operations.


Table 4 Northfield and Bowen 2010 PM Northfield/Bowen EBL EBT EBR WBL WBT WBR SBL SBT SBR NBL NBT NBRLane Configurations 0 <2> 0 0 <2> 0 1 2> 0 1 Volume (vph) 247 151 126 94 291 99 78 694 215 282 780 36 Total Split (sec) 28.3 28.3 0.0 28.4 28.4 0.0 12.2 39.7 0.0 23.6 51.1 0 Total Split (%) 23.6% 23.6% 0.0% 23.7% 23.7% 0.0% 10.2% 33.1% 0.0% 19.7% 42.6% 0% Maximum Green (sec) 22.1 22.1 22.2 22.2 6.1 33.9 17.4 44.9 0 v/c Ratio 0.97 1.02 0.42 1.03 0.98 0.82 Control Delay 72.1 85.1 24.8 78.5 79.8 40.3 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay 72.1 85.1 24.8 78.5 79.8 40.3 LOS E F C E E D Approach Delay 72.1 85.1 74.2 50.5 Approach LOS E F E D Queue Length 50th (meters) 73.4 ~83.5 10.5 ~125.6 60.1 111.6 Queue Length 95th (meters) #99.4 78.7 19.5 #165.7 #115.0 #140.7

This analysis shows the potential level of service if signal operations were optimised at this currently signalised intersection. Current operations may be somewhat different if the timing plan is not optimised. Northfield operates at LoS E and F, Bowen operates at LoS C, D and E. Queue blocking issues discussed alter the perception of operation. In addition to this “optimised for progression" scenario, we examined two other situations: operate the Northfield/Boxwood intersection under the upgraded configuration as a two-way stop and, operate the Northfield/Boxwood signal at half the cycle length of the Northfield/Bowen signal. As an unsignalised intersection delay would be excessive, estimated by the software at approximately 4 minutes for the northbound left turn from Boxwood (in practice delay is likely to be lower as drivers will tend to accept shorter gaps than modelled and, the model does not account for platooning from the southbound left turn from Hwy 19 at Northfield). Operation at half the cycle length significantly reduces the delay to the Boxwood northbound left turn traffic but at the expense of additional delay to Northfield traffic as a significant proportion is guaranteed to be stopped at either the Bowen intersection (eastbound) or Boxwood (westbound). Adjusting the northbound left turn phase length with the proposed (progression) timing plan has no significant effect on the delay which is controlled by the overall cycle length. This is typical of signalised intersections with the low side street volumes where the signal is used to improve safety by providing controlled gaps for the low volume movements.


3. 2024

The projected 2024 traffic volumes are analysed to investigate whether the proposed Boxwood connector can reasonably address the identified issues. In addition, this analysis provides insight into future conditions and thus guidance in identifying additional work that may be required or issues that need to be resolved before the Boxwood connector is built. These scenarios include the proposed Boxwood Connector and the reassignment of E/B to N/B left turn traffic (and the reverse) to the Boxwood connector as discussed. They do not include any diversion at Meredith. As discussed above, these volumes are based on regional growth, estimates of development in the area and the specific rerouting of traffic due to construction of the connector and changes to adjacent land access. The specified land uses, together with the trip generation rates, give a 50th percentile traffic volume of 1077 vehicles per hour in the p.m. peak hour for all "new" development in the study area. As discussed in the Sensitivity Analysis below, the actual volume generated and the routes that they are assigned to will vary from those assumed in this analysis. As noted below, traffic operations along Boxwood are generally at a fairly high level with the constraints being imposed primarily by the Bowen/Boxwood intersection operations. Since site-specific uses are not known at this time more detailed analysis is not appropriate. Regional growth, using the assumed growth rates of 1.5% per annum for the first 10 years and 2.5% per annum for the second 10 years gives an aggregate growth of 45% in background (excluding new development) traffic volumes over the 20-year period. Traffic generated from the new land uses proposed amounts to approximately 10% of the total traffic in the AM peak hour and 19% in the PM peak hour. These are combined in the traffic assignment spreadsheet to produce the projected 2024 volumes for each time period. The projected volumes are shown on Figure 3.


a. 2024 A.M. Peak Table 5 Northfield and Boxwood

2024 AM Northfield/Boxwood EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations 1 2> 0 1 2> 0 1 1> 0 1 1 1 Volume (vph) 305 665 146 42 525 315 70 50 20 72 15 229 Total Split (sec) 27 64 0 37 37 0 26 26 0 26 26 26 Total Split (%) 30.0% 71.1% 0.0% 41.1% 41.1% 0.0% 28.9 28.9% 0.0% 28.9% 28.9% 28.9% Maximum Green (sec) 21 58 31 31 20 20 20 20 20 v/c Ratio 0.49 0.35 0.23 0.73 0.41 0.29 0.45 0.06 0.58 Control Delay 13.9 4.4 20 20.7 40.7 27.8 42.3 31.5 10.3 Queue Delay 0 0 0 0 0 0 0 0 0 Total Delay 13.9 4.4 20 20.7 40.7 27.8 42.3 31.5 10.3 LOS B A C C D C D C B Approach Delay 7 20.6 34.3 18.6 Approach LOS A C C B Queue Length 50th (meters) 22.9 19.3 5.1 51.8 12.3 8.6 12.7 2.5 0 Queue Length 95th (meters) 56.4 37.2 m9.9 66.6 23.2 19.1 24 7.4 18.4

This analysis shows the ability of the intersection to carry traffic to the Boxwood connector and on Northfield. All movements on Northfield would operate at LoS A to C, while Boxwood movements would operate at LoS B to D.

Table 6 Northfield and Bowen 2024 AM Northfield/Bowen EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations 1 2> 0 1 2> 0 1 2> 0 1 2> 0 Volume (vph) 73 404 178 43 198 93 151 711 100 242 666 60 Total Split (sec) 10.0 27.0 0.0 9.0 26.0 0.0 13.6 33.9 0.0 20.1 40.4 0 Total Split (%) 11.1% 30.0% 0.0% 10.0% 28.9% 0.0% 15.1% 37.7% 0.0% 22.3% 44.9% 0.0% Maximum Green (sec) 5.0 20.8 4.0 19.8 7.5 28.1 13.9 34.2 v/c Ratio 0.28 0.85 0.35 0.58 0.49 0.75 0.76 0.74 Control Delay 22.1 36.4 30.5 30.0 19.1 15.9 35.8 28.6 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay 22.1 36.4 30.5 30.0 19.1 15.9 35.8 28.6 LOS C D C C B B D C Approach Delay 34.8 30.0 16.4 30.4 Approach LOS C C B C Queue Length 50th (meters) 9.3 54.5 7.0 27.4 8.3 22.1 34.5 69.3 Queue Length 95th (meters) 12.9 69.1 12.1 29.0 m17.8 #39.7 #62.0 89.4

This analysis shows the ability of the intersection to carry traffic remaining on Northfield and Bowen after the connector is in operation. All movements on Northfield would operate at LoS C or D, while Bowen movements would operate at LoS B to D.


Table 7 Boxwood and Bowen 2024 AM Boxwood/Bowen EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations 2 1> 0 1 1> 0 1 2> 0 1 2 1 Volume (vph) 389 59 107 76 88 13 55 661 40 82 704 135 Total Split (sec) 20 20 0 20 20 0 25 37 0 13 25 25 Total Split (%) 22.2% 22.2% 0.0% 22.2% 22.2% 0.0% 27.8% 41.1% 0.0% 14.4% 27.8% 27.8% Maximum Green (sec) 14.0 14.0 14.0 14.0 19.0 31.0 7.0 19.0 v/c Ratio 0.49 0.38 0.19 0.29 0.34 0.74 0.66 0.71 0.27 Control Delay 21.1 20.7 18.9 32.9 49.7 25 64.6 32.3 5.8 Queue Delay 0 0 0 0 0 0 0 0 0 Total Delay 21.1 20.7 18.9 32.9 49.7 25 64.6 32.3 5.8 LOS C C B C D C E C A Approach Delay 21 26.9 26.8 31.3 Approach LOS C C C C Queue Length 50th (meters) 28.8 15.5 9.7 17.4 12 40.8 15.4 60.9 0 Queue Length 95th (meters) 38.1 34.3 18.1 30.9 m13.9 m45.5 #37.0 85.6 13.3

This analysis shows the ability of the intersection to carry traffic on the Boxwood connector and Bowen. All movements on Boxwood would operate at LoS B to C, while Bowen movements would operate at LoS A to E.

b. 2024 P.M. Peak

Table 8 Northfield and Boxwood 2024 PM Northfield/ Boxwood EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations 2 2> 0 1 2> 0 1 1> 0 1 1 1 Volume (vph) 389 433 101 28 782 50 108 57 31 61 14 323 Total Split (sec) 25 82 0 57 57 0 38 38 0 38 38 38.0 Total Split (%) 20.8% 68.3% 0.0% 47.5% 47.5% 0.0% 31.7% 31.7% 0.0% 31.7% 31.7% 31.7% Maximum Green (sec) 19 76 51 51 32 32 32 32 32 v/c Ratio 0.39 0.22 0.07 0.47 0.61 0.36 0.39 0.06 .68 Control Delay 8.9 4.1 5.3 5.3 60.8 37.2 51.5 41.6 11.4 Queue Delay 0 0 0 0 0 0 0 0 0 Total Delay 8.9 4.1 5.3 5.3 60.8 37.2 51.5 41.6 11.4 LOS A A A A E D D D B Approach Delay 6.1 5.3 50.2 18.6 Approach LOS A A D B Queue Length 50th (meters) 11.2 15.1 1.2 17.2 26.2 15.6 14.3 3.1 Queue Length 95th (meters) 20.5 26.5 m1.2 m17.7 42.8 29.7 26.5 8.7 25.7

This analysis shows the ability of the intersection to carry traffic to the Boxwood connector and on Northfield. All movements on Northfield would operate at LoS A, while Boxwood movements would operate at LoS B to E. The timing plan could be adjusted to improve side street LoS if desired, but with some penalty to Northfield operations. See also discussion on page 9.


Table 9 Northfield and Bowen 2024 PM Northfield /Bowen EBL EBT EBR WBL WBT WBR SBL SBT SBR NBL NBT NBR Lane Configurations 1 2> 0 1 2> 0 1 2> 0 1 2> 0 Volume (vph) 53 233 174 114 415 122 154 1038 74 426 967 50 Total Split (sec) 9 27 0 12 30 0 16 48 0 33 65 0 Total Split (%) 7.5% 22.5% 0.0% 10.0% 25.0% 0.0% 13.3% 40.0% 0.0% 27.5% 54.2% 0% Maximum Green (sec) 4 20.8 7 23.8 9.9 42.2 26.8 58.8 v/c Ratio 0.54 0.71 0.87 0.98 0.56 1.02 1.04 0.88 Control Delay 53 39.9 77 72.7 19.6 39.4 85.6 37.4 Queue Delay 0 0 0 0 0 0 0 0 Total Delay 53 39.9 77 72.7 19.6 39.4 85.6 37.4 LOS D D E E B D F D Approach Delay 41.4 73.5 37 51.6 Approach LOS D E D D Queue Length 50th (meters) 10.7 37.6 29.3 ~97.3 9.9 ~42.5 ~103.7 129.7 Queue Length 95th (meters) 20.8 51.4 #40.8 #86.4 m12.5 m#165.1 #163.5 157

This analysis shows the ability of the intersection to carry traffic remaining on Northfield and Bowen after the connector is in operation. All movements on Northfield would operate at LoS D or E, while Bowen movements would operate at LoS B to F. Table 10 Boxwood and Bowen 2024 PM Peak Boxwood/Bowen EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations 2 1> 0 1 1> 0 1 2> 0 1 2 1 Volume (vph) 439 59 82 76 88 13 196 745 40 82 888 337 Total Split (sec) 29 29 0 29 29 0 22 47 0 15 40 40 Total Split (%) 24.2% 24.2% 0.0% 24.2% 24.2% 0.0% 18.3% 39.2% 0.0% 12.5% 33.3% 33.3% Maximum Green (sec) 23 23 23 23 16 41 9 34 34 v/c Ratio 0.84 0.32 0.2 0.31 0.98 0.87 0.52 0.97 0.59 Control Delay 60.8 25.9 21.9 41.4 86.7 26.7 64.5 65.1 13.1 Queue Delay 0 0 0 0 0 0 0 0 0 Total Delay 60.8 25.9 21.9 41.4 86.7 26.7 64.5 65.1 13.1 LOS E C C D F C E E B Approach Delay 52.4 33.1 38.7 51.6 Approach LOS D C D D Queue Length 50th (meters) 60.4 19.6 12.1 23.1 58.1 89.3 20.8 119.6 14.7 Queue Length 95th (meters) 74.3 38.5 20.8 37.7 m#80.2 m96.7 #45.3 #162.1 45.4

This analysis shows the ability of the intersection to carry traffic on the Boxwood connector and Bowen. All movements on Boxwood would operate at LoS C to E, while Bowen movements would operate at LoS B to F.


4. Boxwood Roundabout The proposed roundabout is expected to operate satisfactorily under the projected 2024 conditions as either a single lane roundabout or as a partial 2-lane configuration depending on the laning for Boxwood eastbound (see discussion of the Northfield/Boxwood intersection and left turn lane configuration). The maximum V/C ratio is 0.60 for the southbound (Boxwood) approach in the PM Peak with the partial 2 lane configuration. 5. Sensitivity Analysis

The purpose of sensitivity analysis is to examine the likely range of results should various parameters change. This is required because we know that if we use single-point data the result is not reliable because the chosen single-point is unlikely to be the actual outcome of our projections. It is thus normal practice in analysis to look at a range of outcomes. The following parameters have a normal range within which the value at any point in time can lie: a. Base year traffic counts b. Land-use assumptions c. Trip generation rates d. Regional growth rates e. Various operational parameters in the Synchro model a. Base year traffic counts - these are typically taken on one day, normally Tuesday, Wednesday, or

Thursday, and Saturdays. We know that if we go back and take the counts again the same day the following week we will get answers that may vary by 10% or more (both in total and for individual movements) from those taken on the first day. Whilst both are "correct" for the day they were taken, they simply illustrate the problem. The impact of a 10% change in base year traffic is approximately a 6 years change in the projected horizon year and volumes, meaning that 2024 volumes may occur as early as 2018 or as late as 2030.

b. Land-use assumptions - the projection of future traffic from new development is based on an

assumed type and quantity of land use. This is only one scenario out of a range of possible scenarios for redevelopment of this land. The impact of a change in land use category or amount would depend very much on the amount of the difference and the difference in trip generation rate and is not quantifiable. Locally generated traffic is less significant than non-local traffic on Bowen and Northfield.

c. Trip generation rates - we have used "average" rates from the ITE Trip Generation Handbook for

the analysis of traffic from new developments within the project area. These numbers represent a range for any given land-use that may be as high as +/- 100%. The only way of determining the "correct" trip generation from a project is to count volumes over a period of time after the project is complete and traffic has stabilised, which is clearly impractical for this analysis. The impact of the change in trip generation rate for any individual category depends on the relative number of trips generated by that category compared to others in the area and the magnitude of the change. This is not quantifiable.

d. Regional growth rates - these are subject to variation over time and are dependent on the rate and

type of development within the traffic catchment area of the particular location. They are somewhat dependent on a economic factors, both local and regional, as well is changes in regional mode split (more people using transit, bicycle or walking for example) as well as changes in trip generation rates due to social pressure and other factors. The impact of the change in regional growth rates is similar


to the impact of a change in base year traffic volumes. A consistent 1% rate change over 20 years amounts to a change in design year volumes of 22%.

e. Synchro model parameters - we have used default parameters in most cases, which appear to give

"reasonable" results. A few specific issues were addressed by modifying vehicle driver behaviour parameters. However, over time, such parameters as saturation flow rate, percentage of trucks and busses, pedestrian traffic flows that conflict with turning movements etc. may change. It is not possible to assess the individual or a cumulative impact of changes in operational parameters such as these. This is addressed by periodically updating the analysis with new data.

We have not attempted to identify specific variability in these parameters. As an alternative, we have postulated an overall increase in traffic volumes of 25% above those projected for 2024 in the traffic projection spreadsheet. This increase indicates that the present four-lane configuration of Bowen Road would be inadequate to carry traffic volumes of this magnitude. Given this, it is apparent that such an increase is unrealistic unless significant additional capacity is provided along the entire length of the corridor by upgrading it to a six-lane plus turn lane configuration. No further comment on this scenario is made. Our recommendations for dealing with the uncertainties of the analysis is that the city carry out routine monitoring of traffic volumes including specific parameters required for intersection operational analysis (saturation flow rate etc.) and that traffic operations both be observed and analysed on a planned schedule to ensure that traffic flows are optimised. This includes monitoring the impact of changes in transit, bicycle and pedestrian use to ensure that these modes are adequately addressed by intersection operations.

6. Turn lane lengths recommendations Our turn lane recommendations are provided in Table 11 and are based on the lengths required for “opening day” without the Boxwood Connector, and 2024 with the Boxwood Connector and the projected land use in place. They reflect the stated regional traffic (background) growth assumptions. They are based on the queue lengths documented in Table 12. Table 11 Recommended Turn Lane Lengths for Northfield and Boxwood

E/B LT W/B LT N/B LT S/B LT S/B RT 2010 opening day - intersection only Minimum (1) Minimum 30m None (2) None 2024 with Boxwood connector 100m (3) 85m (4) 45m (5) 30m 30m

Notes:

1. Minimum left turn lane only, through lane queue exceeds left turn bay length 2. Gas station access only, assume single lane design 3. This is approximately the distance to the existing gas station left turn access that may be retained if

practical 4. This is the length required to clear the through lane queue. Actual storage required for LT traffic is “1

vehicle” – minimum. Providing longer storage reduces delay for this movement. 5. Exceeds the available distance between this intersection and the assumed location of the proposed

lane access. The ability to provide left turn access to this laneway requires further review. If Meredith is also included in the diversion, the storage required will be longer.

Our discussion of turn lanes and signal phasing is attached as Appendix 6.


Table 12 Queue Lengths for Northfield and Boxwood E/B W/B N/B S/B LT TH RT LT TH RT LT TH RT LT TH RT

2010 AM

Queue length 50th percentile 0 44m 0 2m 6m 1m 4m

Queue length 95th percentile 1m 113m 0 4m 14m 6m 11m

2010 PM

Queue length 50th percentile 1m 38m 0 2m 16m 1m 3m

Queue length 95th percentile 1m 70m 1m 2m 30m 9m 10m

2024 AM (w/o Meredith divn)

Queue length 50th percentile 23m 19m 5m 52m 12m 9m 13m 3m 0m


2024 PM (w/o Meredith divn)



7. Signal timing plans Synchro data files are provided separately for City for Nanaimo use. Timing plan information for controller setup will be provided to the electrical contractor.


Transportation Analysis Appendices

1. Interim Report on the Concept Plan

2. Trip Generation Rates

3. Trip Generation and Assignment

4. Traffic Operations Observations

5. Volume Adjustments

6. Turn Lane Configuration and Signal Phasing

7. Synchro Timing Plans Note: Appendices 1-6 were written as “in progress” documents during the course of the project. Some comments may refer to the status at that time.


Appendix 1 - Interim Report on the Concept Plan

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Richard James & Associates,4456 Craig Court,

Victoria, BC,V8N 5W3

Tel: 250-721-5897 Cell: 250-514-1188Fax: 250-721-5938

E-Mail: [email protected]

Dear Mr. Anderson, Re: Northfield/Boxwood Connector: Concept Review This interim report reviews the overall concept proposed by the City of Nanaimo for this project with the intention of confirming that it appears capable of addressing the stated issues at the Northfield/Bowen Road intersection. This concept review includes the general layout and operational analysis of the project that includes (see Figure 1):

1. The proposed Northfield/Boxwood signalised intersection and widening of Northfield 2. The proposed new Boxwood link from Northfield to Bowen and associated road connections including

the realignment of Rosstown Road 3. The proposed Boxwood/Bowen signalised intersection 4. The reconfigured Northfield/Bowen intersection 5. Consequential changes to access to Beban Park, Beban Plaza and Northfield Road properties

The design component of the project includes only the proposed Northfield/Boxwood intersection proposed for construction as a 2-lane intersection in phase 1of the project. Our review is attached and confirms that the project is capable of improving future operating conditions at the Northfield/Bowen intersection. Some items are flagged as requiring additional work as stated in our proposal in order to develop an acceptable design and signal timing plans for implementation as a staged project. Summary:

1. Our review confirms that there is a net benefit based on intersection level of service in the 2024 p.m. peak analysis when compared to operating conditions in the design year of 2024 without the proposed Boxwood connector. Since volumes are lower in the morning, noon and Saturday peaks, we expect that operating conditions will be better than those experienced in the weekday p.m. peak.

2. Notwithstanding the net benefit, our analysis shows that Bowen Road in this area will continue to experience high traffic demand and significant delays in the design year (2024) as the project only mitigates one specific aspect of operations on Bowen Road.

3. The project is based on an assumption by the city that a specified number of vehicles will divert from Northfield/Bowen to Northfield/Boxwood/Bowen. Specific action as identified will be required to achieve this.

4. Effective advance signing and an effective timing plan on Boxwood (to provide at least some level of progression for the diverted traffic) will be required to achieve the project objectives.

5. Our review of the traffic generation based on the stated land uses and the routing assumptions shows that these are reasonable. Variations in these parameters will be tested in our sensitivity analysis.

6. Growth rates provided by the city for background traffic growth appear reasonable. 7. We have discussed below and flagged the following items for review as the design progresses:

a. Left turn lane storage lengths b. Review of the proposed relocation of the Beban Mall access to the Beban Park South access

Mr. Douglas Anderson, P. Eng, AndersonCivil Consultants, 206b -335 Wesley Street, Nanaimo, BC, V9R 2T5

Date: April 7th 2010 Project Number: Northfield/Bowen

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c. The potential for on-street parking as shown on the city supplied concept drawing d. Pedestrian and cyclist crossing issues where higher future pedestrian and cyclist volumes may

conflict with critical left turn movements. 8. Next steps

a. Fine tune Synchro model parameters b. Complete analysis of the remaining time periods c. Confirm left turn lane lengths for all time periods d. Produce opening-day signal timing plans, and guidelines for design year timing plans e. Review pedestrian and cycling facility provision f. Review design geometry, signing etc.

Potential Design Changes Our review has covered only traffic operations issues at this time. Bicycle and pedestrian facilities will be reviewed as the roadway layout is refined and the available space is further defined. The current review has indicated that the following changes may be required (only item 1 is directly relevant to the current design component, the other items are required to ensure that the overall concept is functional and best addresses stated objectives):

1. Northfield at Boxwood: extend turn lane storage lengths 2. Boxwood at Bowen: extend left turn storage length and either:

a. Use split phasing for the eastbound left with an exclusive left turn and a shared left-through-right lane with split phasing for east-west movements, or,

b. Dual exclusive left with a shadow island on the Beban Park access with normal phasing 3. Northfield at Bowen: extend left turn storage lengths 4. Potential changes to the proposed Beban Park access 5. Changes on Bowen Road that may be desirable, but are not within the scope of this project, are not

referred to.

Yours truly,

Richard A James, P. Eng., PTOE

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Northfield/Boxwood Connector: Concept Review Introduction The purpose of this task in the project is to review the general intent and assumptions in the project as put forward by the city, to confirm that the general basis of the analysis is sound, and to confirm that there is a reasonable likelihood of the project achieving its goals. This task is split into several components:

1. A review of the land use and trip generation rates used for new development 2. A review of the assumptions behind the reassignment of existing traffic due to changes in the roadway

configurations and access points 3. A review of the assumptions for future growth in background traffic 4. A review of the assumptions for the assignment of traffic from new development 5. An overview of traffic operations to the level required to confirm that reasonable operation is likely to be achieved

The city has provided background information in the form of a concept drawing, a trip generation and assignment spreadsheet, and a brief written description of the trip generation and assignment process. These documents form the basis of our concept review. Basic Project Concepts The goal for the project is to improve the overall accessibility of this part of Nanaimo by maintaining and enhancing the capacity of the Northfield/Bowen and adjacent intersections. In order to achieve this goal the proposal is to relieve traffic congestion at the Northfield/Bowen intersection by diverting left turning traffic from this intersection to other intersections where there may be surplus capacity and retain a system where the demand across the various intersections in the system is more evenly balanced thus making the most effective use of the infrastructure. Integral to the project concept is the development of the land in the northwest quadrant of the Northfield/Bowen intersection between Northfield, Boxwood, Rosstown and Bowen Roads. Development of this land provides the opportunity to construct a new link that can take eastbound left turn traffic from Northfield/Bowen and reroute it as left turn traffic through Northfield/Boxwood and Boxwood/Bowen in the vicinity of the current Rosstown/Bowen intersection. In this concept Rosstown would be disconnected from Bowen Road and reconnected to Boxwood. In addition, use could be made of the Boxwood/Meredith link by diverting northbound left turn traffic at Northfield/Bowen to turn left at Meredith and left again at Boxwood/Northfield. This option is not reviewed in this project. Due to the existing network configuration and land use (Beban Park and Beban Mall), there are no acceptable alternative routes to divert southbound and westbound left turn traffic at the Northfield/Bowen intersection. Current traffic operations issues The key operations issues at the present time have been identified by the city as:

1. The Northfield/Bowen intersection is operating "beyond practical capacity" with significant delays 2. Due to the roadway configuration and volumes, the signal timing pattern is not as efficient as would be

desirable (split phase timing on Northfield Road) 3. There is some unquantified traffic diversion to Boxwood (south of Northfield) and Meredith (Bowen

northbound left turn and Northfield eastbound right turn traffic)

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In addition, our observation of traffic operations on Wednesday, February 10 and Saturday, February 13 identified the following issues:

1. Numerous left turn violations of the protected to permissive changeover were observed particularly for the northbound Bowen Road left turn. In some cases up to 4 vehicles made this movement after the beginning of the amber arrow phase. This has a significant collision risk and one "near miss" was observed on Wednesday.

2. "Queue blocking" was observed to occur on occasion for Northfield eastbound and Bowen northbound where vehicles were not able to enter the appropriate lane as the through or left turn lane queue blocked the diverge point. Although the same situation occurred for Bowen southbound it is not as significant as the left turn volume is significantly lower. When queue blocking occurs the result is "starvation" of the left turn phase which terminates prematurely leaving vehicles queuing at the end of the through phase.

3. Unbalanced lane usage was observed particularly for Bowen Road where there were significantly more vehicles generally in the curb lane rather than a more equal sharing between the two through lanes. This results in "starvation" of the second lane and unnecessary extension of the phase due to the continuing flow of vehicles that occurs in the overloaded lane.

4. These two observations (2 and 3) indicate that the system is not operating at its potential capacity at this time. 5. In general, standing queues did not develop and all remaining vehicles were generally cleared in the next

cycle or in a few cases the second following cycle. Transportation Background Bowen Road functions as a major north-south connector between Terminal Avenue south of Pearson Bridge looping to the west and reconnecting to Highway 19A near Country Club Mall. It forms a major transportation artery in the city as well as serving significant commercial and retail development adjacent to the corridor. Northfield Road was a historic, but relatively minor, connection between Bowen Road and Highway 19A. With the development of the Parkway (Highway 19) and its connection to Northfield Road, Northfield has become a much more important east-west connector, especially between the Parkway and Bowen Road. Although there is some redevelopment of land within the historic developed area of Nanaimo, most new development is on the north, west and southern fringes and is distributed through Nanaimo using the Parkway. The Parkway also carries through traffic from Highway 1 south of the downtown (Cedar Road) to Highway 19 (south of Ware Road) serving the entire north and west of Vancouver Island. However, true through traffic (to and from outside the Nanaimo urban area) on Highway 19 is believed to be less significant than local traffic circulating within, or traffic with either an origin or destination in Nanaimo. Bowen Road continues to service significant commercial frontage development both in the immediate vicinity of intersections and between intersections. It thus serves as both a through route and direct access to destinations along it. Enhancing the network capacity of Northfield and Bowen Roads is a key strategy within the City of Nanaimo to maintain an appropriate level of service to the travelling public for all modes of transportation including cars, trucks, buses, cyclists and pedestrians. The intention is therefore to achieve a more balanced capacity through the many intersections along these major routes to maximise the value from the existing infrastructure. In this context various spot improvements such as this project may be required to achieve these goals.

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Project Description The components of the project are (see Figure 1): Phase 1:

1. Initial construction of the signalised intersection at Northfield/Boxwood as a two-lane intersection but compatible with future upgrading to 4 lanes on Northfield Road

2. Future Widening of Northfield Road to 4 lanes from west of Boxwood to east of Bowen Road including construction of a raised median and left turn slots on Northfield Road between the Boxwood intersection and Bowen Road

3. Phase 2:Future construction of a connector "Boxwood" between Northfield and Bowen Road 4. Rerouting of Rosstown to the new Boxwood link and construction of a roundabout 5. Construction of the signalised intersection at Boxwood/Bowen connecting to the Beban Park south access

and potential relocation of the Beban Mall access to this intersection 6. Construction of raised median and left turn slots on Bowen Road between Northfield and the new

Boxwood intersection 7. Providing for conceptual development access to the parcels enclosed by Northfield, Rosstown and Bowen Roads 8. Improved operation through more appropriate signal timing plans facilitated by diversion of traffic and

construction of left turn lanes The new Boxwood/Bowen intersection would be a four legged signalised intersection connecting Boxwood Road and the Beban Park access into a single all-movement intersection with Bowen Road. As a result of the location of new intersections and the provision of raised medians some frontage access will be limited (restricted to right-in the right-out only). In the case of the Beban shopping centre this left turn access may be replaced by a new connection to the Beban Park access providing that sufficient intersection spacing can be achieved. Land Use and Trip Generation The land-use categories for new development in the immediate vicinity of the project where driveway volumes have an impact on the system have been identified by the city and are shown in Table 1. The city used the ITE Trip Generation Handbook 5th edition (Institute of Transportation Engineers, Washington, DC) as the source for trip generation rates. We have reviewed this data using the current 8th edition and note that the changes are insignificant (generally 2% or less). This is not considered significant in the context of the overall traffic volumes for the project. The traffic generation and assignment spreadsheet has been updated to reflect these changes as well as the 2010 traffic counts.

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Table 1 Trip Generation Comparison

Notes:

1. This is based on the equation with GLA as the variable 2. This category (congregate care) has only three data points therefore the data is unreliable 3. The difference between the 5th and 8th edition rates is insignificant 4. Proportion Inbound (5th edn), 8th edn. Values 5. See discussion below

Congregate care facilities have some traffic operations parameters similar to other medical facilities such as hospitals. There is a requirement for staffing overlap during shift changes that results in distinct short duration directional peaks in traffic. If these peaks occur during "the peak of the adjacent street", transient traffic operation impacts may occur that are not adequately reflected in an analysis based on the normal "peak 15 minutes of the peak hour". These conditions should thus be considered in addition to the normal analysis. This also has a significant impact on the parking requirements and the ease of access to parking facilities within the site in order to avoid impact on the adjacent intersections caused by delay or difficulty in accessing parking (this is beyond the scope of this review). Background Traffic Growth We understand that the City of Nanaimo does not have extensive information on historic traffic volumes that would allow derivation of data based traffic growth projections, either citywide, or, for the specific corridors included in this study. City staff therefore provided an estimate of future growth rates that we believe is consistent with those generally experienced on Vancouver Island. The impact of potential changes in these growth rates will be reviewed in a sensitivity analysis. Traffic Assignment The city has provided a macro-driven Excel spreadsheet within which they have derived traffic assignments (routing) for the following categories of traffic

1. Traffic from new developments 2. Existing traffic rerouted as a result of the project limiting left turn access to certain properties 3. Traffic to be diverted from turns at the Northfield/Bowen intersection (eastbound to northbound and

reverse)

Zone Development Description

ITE Trip Gen Code

# of Units

Units 5th Ed. Rate

8th Ed. Rate

Range Proportion Inbound 4

zA Future: Multifamily: Low Rise Apartments

221 325 Units 0.58 0.58

0.38 – 0.98

(.66 ) .65

zA Future: Commercial (retail)

820 80,000 1k sq ft 6.56 6.58 1, 3 0.68 – 29.27

(.50) 0.49

zB Existing Commercial approx 65k gross sq ft

Obs Sat Peak

65,000

zC Beban Park Recreation

Obs Fri PM Peak

zD Future: Care Home, 80 units (congregate care)

252 80 Units 0.175 0.17 2 0.16 – 0.19

(.56) .55

zE Future: Townhouse

230 60 Units 0.54 0.52 3 0.18 – 1.24

(.65) 0.67

zE Future: Single Family

210 115 Units 1.02 1.01 3 0.42 – 2.98

(.65) 0.63

zF Existing Commercial Approx 25k gross sq ft

Scaled to zB

25,000

Page 7

Assumptions in these assignments include:

1. Traffic from new developments is assigned to an access point at the middle of the link and thus appears at the adjacent intersections

2. Rerouted traffic is removed from the system based on a general understanding of existing routing patterns through the existing roadway configurations and the general distribution of land use in Nanaimo

3. This rerouted traffic is then reassigned recognising both access point restrictions and the new network connection (Boxwood)

4. Traffic diverted from the Northfield/Bowen intersection turns is reassigned to the new links based on a target eastbound left turn volume at Northfield/Bowen that the city believes is achievable.

We have reviewed with city staff the assumptions listed as 1-3 and believe that these are reasonable assumptions for this project. Assumption 4, rerouting of left turns to Boxwood/Bowen and possibly Meredith/Bowen, reflects the desire to achieve workable operations with a particular configuration by balancing the volumes. The achievability of this depends on user reaction and willingness to take the alternative routes. In assessing the feasibility of achieving these assumptions the following should be considered: 1. Driver knowledge:

a. Local drivers may be advised at the opening of the project of the alternative routing and the potential benefits to be gained by taking it

b. Non-local drivers will have to be advised solely by appropriate signing placed in advance of the intersections such that they can read, understand, and react to the signing appropriately and safely.

2. Intuitively, replacing a single left turn with two left turns does not seem to be productive. However drivers may

find that with the changed roadway configuration and signal timing plan, there is still significant delay to left turns at Northfield/Bowen and northbound at Bowen/Boxwood unless a considerable number of drivers do in fact make the change in routing and continue to do so after the initial opening period of the project.

3. Operating issues that would arise if sufficient drivers do not change their routing include:

a. Excessive delay to left turning traffic b. Excessive delay to through traffic due to the left turn queue exceeding the length of the left turn lane and

thus blocking the adjacent through lane which reduces the capacity of the intersection for through traffic.

4. Potential solutions to these problems would include: a. Changing the signal timing plan to allow a longer green phase for left turns at the penalty of through traffic b. Optimising the signal timing to achieve better signal coordination between the eastbound left turn at

Northfield/Boxwood and the eastbound left turn at Boxwood/Bowen without unduly compromising potential progression on Bowen Road

c. Extending the left turn slot to accommodate the increased queue length, with or without changes to the timing plan

d. An additional public information campaign stressing the routes that should be taken.

In our initial operational review we have considered the intersection delays through the system by both the existing route and the Boxwood route to provide an indication of whether drivers might perceive a real saving in time by taking these alternative routes. This will be a key determinant of their willingness to use the route and thus the success of the project.

In our detailed analysis we will review a limited number of timing plan or turn lane storage length alternatives to identify whether or not these are appropriate solutions.

Page 8

Operational Review Major intersections In this initial "proof of concept" task for this project, the objective is to assess the likelihood of acceptable operation by examining the assumptions and using a very approximate method of assessing intersection operation. We have used "critical lane analysis" to assess the operation. This technique identifies the highest conflicting pairs of per-lane volumes in each direction and uses a nominal saturation flow that implicitly allows for inefficiencies such as lost time etc. to provide a volume to capacity (v/c) ratio that guides the assessment. The city provided estimated 2024 traffic assignment volumes shown in Figure 2 that have been used with the signal phasing assumptions of:

1. Northfield/Bowen and Northfield/Boxwood would operate with protected left turns 2. Boxwood/Bowen would operate with an eastbound split phase due to the shared lane configuration

proposed 3. Bowen/Meredith is not analysed in this project

The circled volumes on Figure 2 and lanes are those that are “critical” for the projected volumes. The results of this analysis are summarised in Table 2. Table 2 Traffic Operations Overview

N/S volume E/W volume V/C Comment Bowen/Boxwood [(1070+221)/2]/1600+159/1400 [(392+50)/2]/1400+88/1400 0.77 Split phase e/w Bowen/Northfield [(1063+40)/2]/1600+308/1400 51/1400+[(133+511)/2]/1600 0.80 Northfield/Boxwood 10/1600+ 154/1400 416/1400+[(21+692)/2] 0.63

In this analysis a v/c ratio of 0.8, or less, indicates that it is likely that an acceptable Level of Service could be obtained if the projected traffic volumes are achieved. Based on this overview we conclude that it appears likely that acceptable operation of the major intersections can be achieved with the stated assumptions and traffic volumes. Land access The project includes provision for implementing an access management strategy for the roads in this area:

1. Management of existing accesses

Northfield: restriction of existing mid-block access to right-in right-out only on the south side of Northfield. Comment: the south-side access is desirable to minimise left turns into the proposed laneway off of Boxwood. The northbound left turn exit movement cannot be provided safely at this point. However, the westbound left turn entry should be retained to minimise left turn access to the proposed laneway on Boxwood south of Northfield due to the very restricted intersection spacing at that point. There should be adequate gaps in traffic approaching from the west as the turns from the side street at Boxwood are relatively low volume.

Bowen Road: removal of the two accesses at Beban Mall on the east side of Bowen is desirable as safe left turns cannot be provided at any location along this segment of Bowen Road. Left turns in and out are proposed to be provided from the realigned Beban Park access that makes provision of right-in right-out access from Bowen Road redundant as it can be more safely provided by this access.

Page 9

2. Provision of access to developable property which would be serviced by Boxwood Access to potential development parcels between Boxwood, Northfield and Bowen roads is adequately provided by the link between the Rosstown/Boxwood roundabout and Bowen Road. Boxwood gives all direction access to these parcels via either Bowen or Northfield Roads. The Northfield access should be reviewed since the property north of Northfield can be adequately serviced by the proposed internal service road. Access to the parcels north of Boxwood towards the relocated Rosstown Road should be provided only from the relocated Rosstown Road and not from Boxwood. Access to the existing Esso gas station from Boxwood is problematic. When Boxwood is connected to Bowen Road this access will not be able to provide left turns in or out, and right turns out will conflict with a high volume of traffic entering the right turn lane to join Northfield westbound.

On Street parking: The provision of on-street parking on Northfield Road west of Bowen Road requires more detailed review than can be done at this stage of the project. Specifically, off-peak traffic volumes and laning requirements at intersections must be carefully reviewed to ensure that the available signal capacity can in fact be utilised when there is a vehicle parked in the curb lane. This is a complex evaluation that needs to address lane continuity between intersections, the risk of collision with "unexpectedly parked" vehicles in what may be regarded as a through lane, the impact of parking and leaving vehicles effectively blocking the available travel lane, the impact on bicycle traffic in the curb lane (specifically the "door opening issue"), queue blocking at the intersection and the resultant impact of these issues on the ability of Northfield to act as an arterial road whose primary function is to carry high traffic volumes. In situations such as this a developer would be expected to provide on-site parking, with rear access, to meet their full parking demand. Exceptionally, an added lane for parking in addition to the through lanes required for traffic flow may be provided at the developer’s cost including dedication of right-of-way. An additional concern is that if parking is allowed in the curb lane and there is a raised median there is only one available traffic lane which could be blocked by a collision or stalled vehicle with no way for other vehicles to pass around the scene. This effectively closes the road to traffic in one direction, which may not be an acceptable outcome especially on an arterial road. This comment also applies to Boxwood where a separate parking lane is proposed with one through lane and a raised median. The existing substandard parking along the front of the building in the north-east corner of the Northfield/Bowen intersection should be further reviewed on safety concerns. Off-street parking at this location is impractical; it may be replaced by widening the street to accommodate on-street parallel parking. However significant impact on traffic operations would be expected especially during peak hours where parking and leaving vehicles will obstruct traffic thus decreasing the efficiency of an already heavily loaded intersection. Transit: The concept plan indicates a transit route down the realigned Rosstown, Boxwood and then to Bowen Road. The roundabout will have to be designed to accommodate transit vehicles as well as trucks that may require access to property serviced by Rosstown Road unless an alternative access with an appropriate design standard is available. At Bowen Road busses turning right to travel southbound on Bowen Road must be able to turn into the curb lane without infringing on the adjacent lane. Similarly busses turning left (northbound) off of Bowen into Boxwood must be able to stop clear of other traffic turning into Boxwood whilst they are at the transit stop which therefore needs to be in a separate lane which then becomes the parking lane (if provided).

Page 10

Bicycle and pedestrian facilities: Continuous bicycle and pedestrian routes with safe crossing places are an essential component of today's transportation systems. Provision of pedestrian facilities on both sides of roadway is normal and expected. Similarly, bicycle facilities need to address both routing patterns and the level of ability and confidence of their users. This is particularly important in the vicinity of a facility such as Beban Park with a high recreational use component. The proposal identifies on and off road and bicycle facilities that may be separated from pedestrian sidewalks. The ability to achieve this should be reviewed during the early stages of our detailed design review. Pedestrian crossing of Bowen Road may have to be restricted to crosswalks with the least impact on traffic operations from conflicts with the left turns. This will be carefully reviewed in the design and analysis to ensure that an acceptable balance is achieved between pedestrian and bicycle access and the needs of all road users.

Signal Operation Analysis As a component of this initial review we carried out an operational analysis using the Synchro traffic analysis software and observed the simulation in SimTraffic. This was carried out as an overview analysis using the city supplied model adjusted to correct geometry and using the city generated 2024 volumes based on 2009 and prior year counts and routing parameters derived from these. The analysis for production of opening day timing plans will use the 2010 counts and routing parameters derived from them. For this comparison we looked at the three key intersections Northfield/Boxwood, Northfield/Bowen and Bowen/Boxwood. Two PM peak scenarios were reviewed:

1. 2024 projected volumes on the existing network with the land use in the north-west quadrant served by a local road system only with no through connection such as Boxwood

2. 2024 projected volumes on the future network with the proposed Boxwood connector in place. This comparison clearly indicates the impact of the connector given the stated assumptions regarding traffic growth and land use changes in the immediate vicinity of the project. The following tables compare key parameters that illustrate this comparison. Table 3a Delay Comparison Bowen/Northfield

Split = phase time in seconds, LoS = Level of Service In 2024 with the current roadway configuration and the projected traffic volumes, the Bowen/Northfield intersection would operate at a very low level of service with extensive delays for all major movements. A long

Bowen/Boxwood E/B W/B S/B N/B 2024 No

Connection LT TH RT LT TH RT LT TH RT LT TH RT

Split (C=150 sec) 29 33 14 18 20 88 15 83 83 Delay (sec/vehicle) 60 41 52 75 43 16 38 38 9

LoS E D D E D B D D A Approach Delay/LoS 52/D 66/E 19/B 36/D

2024 Boxwood

2 Lane LT LT TH RT LT TH RT LT TH RT LT TH RT

Split (C=100 sec) 29 13 12 47 11 46 46 Delay (sec/vehicle) 57 47 67 48 28 11 30 34 5

LoS E D E D C B C C A Approach Delay/LoS 52/D 56/E 13/B 29/C

Delay Difference -3 +6 +15 +27 -15 -5 -8 -4 -4

Page 11

cycle length of 150 seconds is required in this scenario (C=150 sec). By introducing the Boxwood connector, cycle length and delays are substantially reduced and the level of service improved providing that the predetermined reassignment of traffic to the Boxwood connector actually takes place. This is achieved with protected/permissive signal phasing. Table 3b Delay Comparison Northfield/Boxwood

The Northfield/Boxwood intersection would operate in 2024 with the current roadway configuration and the projected traffic volumes at an acceptable level of service for all movements. This is due to the significantly lower side street volumes that are only servicing the adjacent development. By introducing the Boxwood connector and adjusting the signal timing plan, delays are reduced for all movements except the eastbound left turn that increases marginally but still yields a Level of Service C which is considered very acceptable. Table 3c Delay Comparison Bowen/Boxwood

The Bowen/Boxwood intersection would operate in 2024 with the current roadway configuration and the projected traffic volumes at an acceptable level of service for all movements. This is due to the significantly lower side street volumes that are only servicing the adjacent development. By introducing the Boxwood connector and adjusting the signal timing plan, delays are reduced for Bowen Road movements but are somewhat increased for

Bowen/Northfield E/B W/B S/B N/B 2024 No

Connection LT TH RT LT TH RT LT TH RT LT TH RT

Split (C=150 sec) 21 42 11 32 19 70 27 78 Delay (sec/vehicle) 153 48 46 129 85 84 141 56

Los F D D F F F F E Approach Delay 80/F 122/F 84/F 74/E

2024 Boxwood


Split (C= 100 sec) 9 26 9 26 14 43 22 24 Delay (sec/vehicle) 32 41 39 59 44 17 56 49

LoS C D D E D B E D Approach Delay/LoS 40/D 57/E 21/C 50/D

Delay Difference -121 -7 -7 -70 -41 -67 -85 -7

Northfield/ Boxwood

E/B W/B S/B N/B

2024 No Connection

LT TH RT LT TH RT LT TH RT LT TH RT

Split (C=150 sec) 29 110 81 81 40 40 40 40 40 Delay (sec/vehicle) 12 6 21 23 77 40 54 49 13

LoS B A C C E D D D B Approach Delay/LoS

2024 Boxwood


Split (C= 100 sec) 34 73 39 39 27 27 27 27 27 Delay (sec/vehicle) 22 5 13 12 52 26 35 31 8

Los C A B B D C D C A Approach Delay 12/B 12/B 45/D 13/B

Delay Difference +10 -1 -8 -11 -25 -14 -19 -18 -5

Page 12

sidestreet traffic. Levels of service are generally in the D to E range in both scenarios. For this analysis we have used the double left turn lane configuration on Boxwood. Observations from the Analysis In the course of this review the following observations were made:

1. Signal coordination: coordination appears feasible along Northfield however along Bowen it appears problematic, especially in the northbound direction. As a general comment, it is usually trivial to achieve progression in one direction on a street and this may be what has to be done in this case with coordination being applied in the direction that results in the greater benefit to traffic. This may be in a different direction between the morning and afternoon peak periods. Along Boxwood, some degree of progression may also be feasible but this requires more detailed analysis.

2. Left turn storage lengths: the left turn storage lengths shown on the concept drawing eastbound on

Northfield at Boxwood and at Bowen, eastbound on Boxwood at Bowen and northbound on Bowen at Northfield and at Boxwood may be inadequate to accommodate the projected queues. If sufficient underutilised time is available it may be feasible to alleviate this problem by extending the amount of left turn storage provided. This might be practical on Northfield. On Boxwood at Bowen however, a more appropriate solution may be to use a dual left turn lane configuration (or left turn plus a shared lane) as this provides greater throughput in a given time period on Boxwood. A shared lane would require split phasing that, though generally avoided as inefficient, may be an appropriate solution in this case if the overall system operation is improved.

3. Bowen Road operation: while it is apparent that the provision of the Boxwood connector improves

operations through the Northfield/Bowen intersection, Bowen Road will remain heavily congested in the future. This will appear to many users to be worse than indicated by the level of service criteria from the analysis. This is due to the lack of adequate signal coordination resulting in multiple stops along this major corridor. It is outside the scope of this project to resolve this issue

4. Beban Park access: the concept for this project includes closing the current two accesses to Beban Plaza

off of Bowen Road and replacing them with a single access connected to the Beban Park access driveway at the north end of the development. Conceptually, this will give improved access especially for left turn entry and exit to this development. Whilst this is sound practice, it is apparent from observing the traffic simulation that the spacing between a driveway that misses the tennis courts and the Bowen Road intersection is inadequate to store exiting traffic from the shopping centre and will result in queue blocking which may impact the operation of Bowen Road and the access. In addition, during discharge periods from events in the park, traffic from the park will also block exiting traffic from the shopping centre. Further discussion of this concept is required but is outside the scope of the present project.

Revd. RAJ April 7 2010

Appendix 2 - Trip Generation Rate Review We have reviewed the p.m. peak trip generation rates used in the traffic analysis spreadsheet and make the following comments. In general the rates used for the identified categories, although based on the ITE Trip Generation Manual 5th Edition (Institute of Transportation Engineers, Washington DC), are consistent with those in the 8th Edition (2008, ITE) as noted below.

Our comments are as follows:

1. This is based on the equation with GLA as the variable 2. This category (congregate care) has only three data points therefore the data is unreliable 3. The difference between the fifth and eighth edition rates is insignificant

Trip generation rates for the a.m. peak and Saturdays are also available from the ITE manual and will be used in the analysis of these time periods. Noon rates are generally not available in tabular format. Noon rates for residential are generally low, noon rates for commercial can be derived from tabulated data in the ITE manual as percentages of peak period rates. "Captured trip component" - if this is intended to be traffic internal to the zone (that never gets to the adjacent street system) then care needs to be taken to ensure that the value used is representative of what might happen within that zone. For example, if the entire zone is residential, is it reasonable that some peak period traffic will travel between a residential origin and destination in the same zone? Similarly, if the entire zone is commercial (shopping centre or other aggregated development) and is treated as one entity (single area and trip generation rate) then internal capture is already embedded in the trip generation rate since it is based on "shopping centre" surveys on the boundary of the site. On the other hand if this is intended to be "diverted traffic" from another route then this does not change the trip generation but does change the routing of traffic to and from the site. It would appear that in the case of this project an adjustment for captured trips (internal to the site) and diverted traffic is not appropriate. Revd RAJ March 15 2010

Zone Development Description

ITE Trip Gen

Code # of

Units

Units 5th Ed.

Rate

8th Ed. Rate

Range 8th Ed. % Enter

zA Future: 325 Units Multi-family

221 (p350)

325 Units 0.58 0.58

0.38 – 0.98

65%

zA Future: 80k Sq Ft of Commercial

820 80,000 1k Sq ft

6.56 6.58 1,

3 0.68 – 29.27

49%

zB Existing Commercial (Approx 65k Gross Sq Ft )

Obs Sat Peak

65000

zC Beban Park Obs Fri PM Peak

zD Future: Care Home of 80 Units

252 80 Units 0.17 0.17 2 0.16 – 0.19

55%

zE Future Single Family /Townhouse,

230 60 Units 0.54 0.52 3 0.18 – 1.24

67%

zE Future: Single Family /Townhouse,

210 115 Units 1.02 1.01 3 0.42 – 2.98

67%

zF Existing Commercial (Approx 25k Gross Sq Ft )

Scaled to zB

25,000

Page 1 of 2

Appendix 3 - Trip Generation and Assignment We reviewed the spreadsheet constructed by the city of Nanaimo with Gordon Foy on February 10, 2010. The spreadsheet is a multi-page calculation taking existing traffic volumes, proposed land use categories, trip generation rates, background traffic growth rates, and traffic routing adjustments based on the elimination of specific turns and the creation of new routing patterns through the system. The result is a new traffic assignment for various horizon years with and without the proposed Boxwood connection The process comprises four significant steps:

1. Trip generation - new land uses 2. Background traffic growth rates 3. Traffic routing adjustments 4. New traffic routing patterns

1. Trip generation - new land uses

Trip generation rates used by the city of Nanaimo were taken from the ITE Trip Generation Handbook 5th edition. We have reviewed the categories and data and compared them to the current 8th edition and note that the changes are minor and do not significantly impact the analysis (as documented in our corridor review report). The traffic volumes generated are applied to the network volumes as described in section 3 - routing adjustments 2 - traffic reassignment.

2. Background traffic growth rates We understand that the city does not have an extensive database of traffic growth rates although they recognise that these are probably different in various areas of the city. The city uses an average growth rate of 2% for traffic but recognises that traffic volume growth on the Parkway is probably higher and on some city's streets may be lower (for example Townsite Road has not shown growth in recent years). For the purposes of this project, the city has used a growth rate of 1.5% per annum from 2009 to 2014 and 2.5% per annum after 2014 for roads in the project area. This is based on the perception that traffic growth in this area is currently constrained by the operation of the Northfield/Bowen road intersection. Traffic to and from the two commercial areas (Zb and Zf) has not been changed as part of the background traffic growth as it is reasonable to assume that these site-specific volumes are not time-dependent. This is a generally accepted principle which recognises that over an extended time period traffic volumes generated by individual developments, where there are multiple similar facilities, tend to remain constant.

3. Traffic routing adjustments The adjustments made in the spreadsheet fall into two areas: 1. Rerouted traffic is removed from the system based on a general understanding of existing routing patterns

through the existing roadway configurations and the general distribution of land use in Nanaimo 2. This rerouted traffic is then reassigned recognising both access point restrictions and the new network

connection (Boxwood) Traffic rerouted to use the Boxwood connector to pass through the area is discussed below. Traffic rerouted as a result of restricting turns through construction of raised medians on Northwood and Bowen, and the conversion of Rosstown/Beban Park access to an all-movement intersection, is rerouted based on the overall proportion of turns by direction at the adjacent intersection that it is removed from or added to. In the absence of specific routing information such as would be obtained by analysis of video recordings or a license plate survey this approach as appropriate. However, for the two commercial zones the volume

Page 2 of 2

used for this reassignment was the Saturday peak volume which was applied to weekday a.m. and p.m. peak traffic volumes. This is probably not realistic and will be considered in our review of the weekday and Saturday traffic counts from February 2010. This may require adjustment in the spreadsheet as discussed below These adjustments have been made by manually entering the identified changes in appropriate cells in the spreadsheet. The spreadsheet includes a number of macros that are then run with the adjustments but without any background traffic. Adjustment totals are then summarised in a separate table within the spreadsheet before being applied to the overall traffic volumes. This was a manual process where the changes were entered separately in each cell following the routing pattern changes. (The alternative procedure of using equations to link the cells and allow entry of a volume in a single location was implemented after this review). We reviewed a sample of the routing pattern changes to determine whether they follow the most likely routing or may need adjustment. We reviewed the February 2010 traffic counts and compared them with those counts used in the construction of the spreadsheet. Through discussion with city staff various adjustments were made to more appropriately represent observed and expected behaviours

4. New traffic routing patterns As a result of change to traffic patterns generated by the new Boxwood link it is necessary to re-route traffic currently travelling between Northfield (west leg) and Bowen (north leg) and divert this to the new Boxwood connection. This was carried out based on a target left turn volume at Northfield/Bowen that the City believes is achievable. We have discussed these target volumes in our concept review report. RAJ Feb 11 2010 Revised March 26 2010

Page 1 of 3

Appendix 4 - Northfield/Bowen Road Intersection - Traffic Operations Observations Traffic operations were observed at this intersection on a weekday (Wednesday, February 10, 2010) and on a Saturday (February 13, 2010). Observation times were: 7 to 9 AM, 11 AM to 1 PM, and 3 to 6 PM on Wednesday; and 10 AM to 3 PM on Saturday. The observations in this document refer primarily to the weekday situation as observed on Wednesday, February 10. Traffic volumes were noticeably lower on the Saturday, February 13 and the problems noted below were less significant. The following general comments are made:

1. Safety issues 2. Signal coordination 3. Lane utilisation 4. Queuing

1. Safety issues

We understand from discussion with City staff that this intersection is one of the worst collision areas in Nanaimo. During our Wednesday observations two incidents occurred that would be classified as "near misses". One was a southbound rear end situation; the other was a northbound left turn "failure to yield". During our observations it was very apparent that for the northbound left turn "failure to yield", especially at the end of the protected left turn phase, is a significant issue with up to 4 vehicles passing the signal on the "amber" which really means up to 2 vehicles were turning left in front of opposing traffic with a green indication (see discussion below).

2. Signal coordination During our observations on Wednesday, it was apparent that platoons of vehicles were approaching the intersection from upstream signals and in some cases arriving just before, at, or just after the beginning of the red phase for that approach. This situation results in longer queuing and greater vehicle delays than when a platoon arrives at the beginning of green, or during the green phase, and can pass through the signal on that phase. That this situation occurs indicates that there is potential for signal coordination along both Bowen and Northfield. This was most noticeable for a northbound Bowen but was also observed for southbound Bowen and eastbound Northfield Road. While we cannot determine timing plans or the effectiveness of coordination with adjacent signals under this project we will consider coordination through the three signals that are involved (Boxwood/ Northfield, Northfield/Bowen, and Boxwood/Bowen). Signal coordination has the potential to increase the capacity by eliminating starvation conditions and phase truncation, as well as reducing vehicle emissions from vehicles that are unnecessarily stopped and accelerating as well as creating user cost savings. (Other than a review of the potential for coordination between the two new signals and the existing Northfield/Bowen signal, signal coordination in the network context is not included in this project.)

Page 2 of 3

3. Lane utilisation In observing queuing behaviour, especially for the southbound Bowen Road direction, it was apparent that there is uneven lane utilisation where the left-hand through lane carries significantly fewer vehicles than the right-hand lane. This is not explained by consideration of the right turn volume since many vehicles in the right lane actually pass through the intersection. It is also counterintuitive in that vehicles in the right lane passing through the intersection may be blocked by a bus at the far side bus stop. However, drivers unfamiliar with the system may also avoid the left-hand through lane as at some intersections this is potentially blocked by left turning vehicles where there is no designated left turn lane. This is the result of inconsistent design along major corridors. This limits the effective capacity of the intersection as the left-hand lane is starved of vehicles for a number of cycles. This may be recognised in our Synchro analysis by adjusting the lane-to-lane split. This can be addressed by a public education campaign focused on advising drivers to use all through lanes at intersections. Obtaining more even lane utilisation has the potential to increase the capacity by eliminating starvation conditions in the lower volume lane, as well as reducing vehicle emissions from vehicles that are unnecessarily stopped and accelerating as well as creating user cost savings. Queue blocking was observed to occur on a limited number of occasions for the northbound left turn lane on Bowen Road and the eastbound left turn lane on Northfield Road. On Bowen Road the through lane queue would extend beyond the beginning of the left turn lane thus

blocking left turning vehicles from entering the lane and taking advantage of the protected part of the green phase resulting in starvation and premature truncation of this phase

On Northfield Road, at the transition from the single to 2-lane cross-section, queue blocking occurred

on occasion when the left lane (left turn and through) queue extended back into the single lane section thus blocking access to the right-hand lane (right turn and through). This results in starvation of the right hand lane resulting in a lower effective capacity for these two movements.

Eliminating queue blocking has the potential to increase the capacity by eliminating starvation conditions in the lower volume lane, as well as reducing vehicle emissions from vehicles that are unnecessarily stopped and accelerating as well as creating user cost savings. Queue length review will be an essential part of our Synchro analysis, whichill be carried forward into the design process to ensure adequate left turn lane lengths are provided so that the possibility of lane starvation is minimised

4. Queuing

Our queuing observations were focused on obtaining a general impression of the amount of queuing that occurs which would be used as part of the Synchro calibration process. Traffic count information that has been collected for this project only collected discharge rate not the arrival rate at the back of queue or detailed queue length information. Our observations will substitute for queue length information. During our observation periods, a significant number of signal cycles passed all waiting and arriving traffic or, a minimal queue was left at the end of the phase. However at least one cycle on each leg was observed where a significant queue formed yet dissipated over the next 1-3 cycles. (Bowen southbound -

Page 3 of 3

queue beyond Beban Park and out of sight, Bowen northbound - queue beyond left turn slot and out of sight, Northfield - queue beyond Boxwood and out of sight.) The movement that appears to be most impacted by queuing is the northbound left turn on Bowen Road. On most cycles the queue at the beginning of the protected green phase passed, however vehicles arriving during the permissive green phase did not always clear the intersection on that phase. This is partly as a result of the lack of coordination along Bowen Road. This could be alleviated without coordination by implementing a lagging instead of a leading protected left turn phase. This has a higher probability of passing all vehicles, as the phase is less likely to gap-out prior to the arrival of a platoon. The observation that the queues rapidly dissipated to an insignificant length indicates that the system is not operating beyond capacity, but sufficiently close that "normal" random changes in traffic flow can result in some instability and result in noticeable queues for short periods of time. As these queues were observed to clear rapidly, there is clearly "surplus" capacity in some cycles therefore the overall system is not at capacity.

5. Beban Park Mall Our observations of the access from Bowen Road to Beban Park Mall indicate low traffic volumes with no significant impact on operation of the through lanes. It appears likely that the trip generation for this site may be lower than the average rates identified in the ITE Trip Generation Handbook for this category and size of land use RAJ Feb 14 2010 Revd April 26 2010

Appendix 5 - Traffic Volume Adjustments - Base Year 2010 The following discussion summarises adjustments made to the counted traffic volumes to produce a more consistent volume set as the base case for analysis and future projections. This is necessary as there are inevitably differences between volumes on the common legs between adjacent intersections as well as between automatic hose counts and manual intersection counts. Automatic Hose Counts For this project 2 mainline hose counts were carried out, Northfield West of Bowen Road, and on Bowen Road north of Rosstown Road. In addition hose counts were also done on Rosstown Road and Beban Park access (South). Consistency checks Two consistency checks were carried out, to compare the hose counts for the peak hours with the adjacent intersection approach/departure volumes, and, to compare the approach/departure volumes recorded in the turning movement counts with those at the adjacent intersection. Assumptions For the purpose of this review we have assumed that the manual turning movement counts, recorded in 5-minute increments, are more likely to be "accurate" than the automatic hose counts. One implication of this is that the turning movement counts derived for Rosstown Road and the Beban Park access are probably less reliable than those at the intersections where turning movements were actually counted. We have also assumed that, since the through movements on Bowen Road are significantly higher than the turning movements, it is acceptable to make the adjustments only to these through movements north of Northfield Road. Based on review of the aerial photography, the area served by Rosstown Road is primarily residential with probably a low likelihood of through traffic. We would therefore expect the exiting volume to be higher than the entering volume in the morning peak with the reverse true in the evening peak when more traffic would enter them leave. It thus appears that the recorded volumes may be inverted and we have made this adjustment in the spreadsheets. Based on a review of the peaks recorded in the automatic count versus the manual intersection counts we observe a better match between the peak recorded on the automatic count than the volume in the same time period as the peak observed in the manual counts. While the time shift is inconsistent between the peak periods, we have used the automatic count peaks as the target for our adjustments. Minor Intersections There are two driveways eastbound and one driveway westbound on Northfield Road between Boxwood and Bowen. For the eastbound direction we have assumed that the traffic generated by "zone F" is represented physically by the two driveways combined into one "node". The volumes is assigned to turning traffic at this location are not derived rigorously from any data that are estimates. This will have no significant impact on our analysis.

On Bowen Road there are two minor driveways in the southbound direction only, the church and gas station. volumes for these have not been estimated. It is expected there is some "leakage" of traffic especially in the southbound to westbound direction through the gas station as a result of normal gas station operations. This is unlikely to be significant in terms of the analysis. The data provided for Dorman Road is a single hour in the afternoon that does not coincide with the observed peak at the Bowen/Northfield intersection. This data thus cannot be used in our analysis. This is not a significant issue since it is not impacted by any diversion of traffic or traffic generated from new land use that is not already recorded and accounted for at other intersections. Comparison of Data The following table summarises these comparisons for each survey time period. We have used the indication "OK" when a volume pair has a discrepancy of less than 10%. A.M. peak Noon P.M. peak Saturday Comments Northfield West OK OK OK OK Northfield/ Bowen OK Note 1 Note 4 OK Eastbound automatic count

volumes lower Northfield East OK Note 2 OK OK Bowen/Beban Mall South OK OK OK OK Beban Mall/Beban Mall OK OK OK OK Beban Mall/Beban Park OK OK OK OK North of RossTown OK Note 3 Note 5 OK Southbound automatic count

volumes lower Note 1: correspondence between the two counts is excellent however in the eastbound direction the automatic count is approximately 25% lower than a manual count at the Northfield approach to Bowen Road Note 2: eastbound correspondence is poor, approximately 20% error. Note 3: the automatic counter is 17% lower than the approach volume derived from the downstream records including the assessment of Rosstown Road traffic. Note 4: correspondence between the two counts is good however the eastbound automatic count is 20% below the intersection approach volume. Note 5: the southbound automatic count is 17% lower than the approach volume derived from the downstream records including the assessment of Ross town Road traffic. RAJ March 21 2010

Appendix 6 - Turn Lanes and Signal Phasing Signal phasing: In general, the preferred sequence of phase options for a left turns as volumes and turning conflicts increase is:

1. Permissive only 2. Protected plus permissive 3. Protected only 4. Split phase - special cases, usually with lane restrictions or conflicts such as rail crossings

For right turns, a short taper approaching a channelized right turn has minimal impact on traffic operations and normally operates under yield control. A "full-length" auxiliary right turn lane would also normally operate under yield control. Under exceptional circumstances where a dual right turn is the appropriate solution, this must be signalised and "no right turn on red" implemented (effectively protected right turn only). Considerations for moving up to a more protected situation include:

1. Design speed: on high-speed facilities protected is generally preferred especially when the opposing volume is high

2. Availability of gaps: if the opposing flow is close to saturation, protected, or protected plus permissive, is required to provide acceptable gaps for left turning traffic

3. Safety: if sight distance is restricted, or there is a persistent collision record that is not resolvable by other means, then protected only is required

4. If additional lanes cannot be provided and a shared (left plus through) lane has to be used then split phasing is required

5. If dual (or triple) lefts are required, then protected phasing is also required Capacity considerations also play a part in this decision:

1. Unless opposing per lane volumes are quite low, left turns over approximately 400 vehicles per hour indicate the need for a dual left to minimise the left turn phase length and storage requirements

2. As overall capacity approaches saturation, additional lanes are indicated with a preference for providing the additional capacity for higher per lane volume movements with a lower saturation flow rate (usually the left turns) unless the issue occurs multiple consecutive intersections were additional through lane capacity may be more appropriate.

Laning issues: Whenever lanes are added or dropped through an intersection, it is critical to successful operation that the lanes extend far enough before and away from the intersection that drivers will actually use them effectively. Ideally, auxiliary turn lane's, either left or right, it should extend upstream for the greater of:

1. The 95th percentile queue in that lane 2. The 95th percentile queue in the adjacent through lanes

If these criteria are not met, then "queue blocking" occurs and the signal may not operate as efficiently as expected as one or more lanes will be starved of vehicles. They will then be carried over into the next phase which can result in rapid accumulation of queues.

On the downstream side of the intersection, an auxiliary lane must extend far enough that vehicles using it can safely merge into the adjacent lane that is operating at the saturation flow of the signal, at least during the saturated part of the phase. Saturation flow implies there are no gaps therefore safe merging cannot occur. If this is not done two situations arise:

1. Forced merges occur which result in slowing through lane traffic and potentially unsafe manoeuvres increasing collision risk

2. Drivers avoid the auxiliary lane which thus operates below capacity and does not fully address the problem it was intended to solve

Examples of inadequate downstream length abound, Northfield eastbound at Bowen Road and Shelbourne Street southbound at Hillside (Victoria) are good local examples. Another example, although admittedly a different situation, is McKenzie westbound at the TransCanada eastbound (Victoria/Saanich) where although a "merge" situation exists vehicles simply cannot do so safely for a significant portion of the day as the adjacent lane is at saturated flow. Application to this project: Discussion and analysis have looked at the Boxwood/Bowen and Northfield/Boxwood intersections in the eastbound direction. Northfield/Bowen has not been considered for an auxiliary lane as the intention of the project is to divert turning traffic away from this intersection to Boxwood. Boxwood/Bowen intersection The city's concept had a dedicated plus shared left turn lane requiring split phasing. Whilst operation seems to be reasonable with this configuration, it is considerably improved with a dual left and separate through/right lane, which allows normal phasing. This requires a three-lane approach on Boxwood but no change in laning on Bowen Road. Northfield/Boxwood intersection Our initial analysis considered only a single left turn lane on Northfield since the opposing volumes are relatively low in both peaks (approximately 420 vph/lane). The projected 2024 left turn volume (approximately 390 vph) can be accommodated within a reasonable timing plan using a single left turn lane. Projected queue lengths are around 105 m. This will cause an issue with the left turn access to the gas station. We have not yet investigated alternative timing that would provide higher capacity for the left turn at a penalty of greater overall delay for the intersection. We have also not investigated in detail the impact of diverting traffic northbound on Bowen to westbound on Meredith and Boxwood, then proceed westbound on Northfield at Boxwood. This would also use the available capacity and may result in longer queues on all legs. Our analysis to date indicates a potential problem with the northbound left turn on Boxwood with 95th percentile queues extending to, or beyond, the proposed lane accessing property on the south side of Northfield. It is desirable to eliminate the left turns into laneways on Northfield, which requires that the left turn be made at this laneway (southbound left turn). One potential solution that addresses both queue length and phasing is to use a dual left northbound which requires offsetting the through lane and matching this alignment on the North leg of the intersection. Consideration of this results in "effective protection" to develop two northbound lanes on the north leg of this intersection. Clearly, with queues blocking this access further discussion of this point is required. The question of a single left turn Lane eastbound, left turn plus shared, or dual lefts at Boxwood has not yet been investigated, as the need did not appear to be critical for the projected traffic volumes. This will be addressed in sensitivity analysis, which may indicate that protection for future changes should be made at this

stage. If this is the case, then two receiving lanes northbound on Boxwood are required and we get into the "lane drop" situation. The distance between Northfield and the Boxwood Ross town connection roundabout is approximately 125 m. This distance includes a curve that further complicates the issue of a potential lane drop in this area. It would appear that this is inadequate distance to ensure that both lanes get fully utilised by left turning traffic. A better solution is to carry both lanes to at least the roundabout and either drop one as a low-volume right to turn lane at the first exit or continue both through the roundabout and to go to Bowen Road with two through lanes which can then become dual lefts plus a through and right lane at the Boxwood Bowen intersection. However given the nature of the facility and the relatively low volumes this configuration appears to be rather generous. Another consideration is the potential variability in the projected traffic volumes in this area. These are based on:

1. Estimated citywide annual growth rates 2. a "single case" land use scenario for local redevelopment 3. and the intended diversion of traffic from the eastbound left turn at Northfield/Bowen

All these are estimates with varying degrees of reliability that will be addressed in our sensitivity analysis. RA J April 21, 2010

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Northfield/Boxwood Intersection Upgrade Transportation ... · We are pleased to present our report on the Transportation Analysis for this project. This report provides a planning