819006 150127 buchanans road v2 subdivision (intersection...

819006 150127 Buchanans Road V2 Subdivision (Intersection Design and Control) © Urbis TPD Limited

Urbis TPD Limited is part of

the Urbis Group of Companies

Davie Lovell-Smith Ltd

PO Box 679

Christchurch

New Zealand

Via Email - [email protected]

Attention: Patricia Harte

27 January 2015

Dear Patricia,

RE: PROPOSED SUBDIVISION INTERSECTION DESIGN AND CONTROL - 221-223 BUCHANANS ROAD (PC80)

I write in response to your request for Urbis to undertake an assessment to determine an appropriate form of design

and control at the intersection of the proposed new subdivision spine road with Buchanans Road and Jarnac

Boulevard. Additionally, as per your instructions, I have consulted with Mr Weng Kei Chen and Mr Mike Calvert of

the Christchurch City Council regarding this matter and summarise the main points of our discussions in this letter.

It is understood that a subdivision application has been lodged with Council, and the information in this letter is

required in response to a request for further information (RFI) issued by the Council regarding that subdivision

application. Therefore, for the benefit of third parties who may be reading this letter, I will also provide context by

way of some brief comments regarding the site, the adjoining road network, the subdivision proposal and some other

background information.

Site and Road Network

The proposed subdivision site is located on the southern side of Buchanans Road, approximately 300m northwest

of Gilberthorpes Road and opposite Jarnac Boulevard (which is the main spine road through the established

Delamain residential subdivision).

North of Delamain is the site of the proposed Noble Village residential subdivision which will also include a significant

commercial element at its northern end adjacent to Yaldhurst Road (SH 73). While the Noble Village development

is currently stalled, Urbis has been verbally advised by one of the developers that they are actively working to resolve

the Yaldhurst Road access issues that have stalled the project and have every intention of continuing with full

development of the residential and commercial elements.

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Intersection Design and Control Proposed Subdivision

221-223 Buchanans Road (PC80)

27/01/2015 2 819006 150127 Buchanans Road V2 Subdivision (Intersection Design and Control) © Urbis TPD Limited

Urbis is also aware of a large football academy development project that has been granted consent to establish

opposite the Noble Village development on the northern side of Yaldhurst Road. Access to that development is

proposed through the creation of a fourth leg to the constructed (but not yet operational) signalised intersection on

Yaldhurst Road that will also serve the Noble Village development.

Figure 1 below shows the location of the proposed subdivision site in the context of the surrounding road network

and nearby development sites.

Figure 1: Subdivision Site Location and Surrounding Road Network

Background

The proposed subdivision site is located within a larger site area that is subject of a proposed plan change (PC80)

to rezone the site from Rural 5 for residential purposes. PC80 was originally prepared as a private plan change

request by C S Luney Ltd, but was subsequently adopted by the Council as its own plan change. Information on the

Council's website1 indicates that PC80 is currently 'in preparation'. However, it is understood that the Council is not

proceeding with PC80 because of the requirement by the Minister for Earthquake Recovery that a Land Use

Recovery Plan (LURP) be prepared. After consultation, the LURP came into effect in December 2013 but did not

zone this Buchanans Road land as anticipated. It did however require the Council to rezone this land, and other

“priority greenfield area” in a Replacement District Plan. The first stage of the proposed Christchurch Replacement

1 http://www.ccc.govt.nz/thecouncil/policiesreportsstrategies/districtplanning/cityplan/proposedplanchanges/index.aspx

Application Site

Buchanans Road

Main Sth Road SH1

Gilberthorpes Road

The Hub Shopping Centre

Carmen Road SH1 / SH73

Pound Road

Waterloo Road

KEY:

Major Arterial Road

Minor Arterial Road

Collector Road

Delamain Subdvn

Proposed Football Academy

Noble Village Subdvn

Roberts Road




District Plan was notified in August 2014 and it rezoned the full South Masham area as Residential New

Neighbourhood as well as including the South Masham ODP.

The proposed subdivision site is located within an even larger site area extending south to Roberts Road that has

variously been identified as Greenfield Residential Area CW2 in Proposed Change 1 to the Regional Policy

Statement, Priority Greenfield Area R10 and Greenfield Priority Area-Residential in the LURP. In conjunction with

the PC80 and the latest Residential New Neighbourhood zoning an outline development plan (ODP) has been

developed and accepted for this larger area. The main feature of the movement layer of the ODP was a main spine

road that connected Buchanans Road (at the Jarnac Boulevard intersection) through to Roberts Road at a point

approximately 450m west of Gilberthorpes Road. T

Urbis prepared a traffic impact assessment (TIA) for the plan change application prepared by C S Luney Ltd that

considered potential effects associated with residential development of around 60 dwellings on the PC80 site as well

as full residential development (around 255 dwellings) of the ODP area. Although the detailed design and control of

the main subdivision/ODP spine road with Buchanans Road and Jarnac Boulevard was not included in the brief for

the TIA, preliminary discussions were held with Mr Chen regarding the Council's preferences on these matters. As

apparent from the existence of large boundary splays either side of Jarnac Boulevard at Buchanans Road, the

Delamain subdivision was developed on the basis that there would most likely be a large roundabout (similar to that

at the Buchanans-Pound intersection) installed at the Buchanans-Jarnac intersection upon future development of

land to the south of Buchanans Road. Despite this, Mr Chen advised in those discussions that the Council's

preference had changed to the intersection of the new spine road with Buchanans Road and Jarnac Boulevard being

in the form of a signalised cross junction.

The applicant has advised that significant effort has been made in the development of the current subdivision

proposal to ensure that the general layout is consistent with the movement layer of the ODP and Mr Chen's indication

that the Buchanans-Jarnac intersection would most likely be signalised.

Current Subdivision Intersection Issues

As advised it became apparent at the outset of this current assessment that there was an issue regarding the

alignment of the proposed new spine road in that its narrower width and slight offset from Jarnac Boulevard would

create difficulties in designing a suitable signalised (or unsignalised) cross junction layout at the existing Buchanans-

Jarnac T-junction. Preliminary communication with Mr Calvert revealed that this issue was also a concern of the

Council.

Road Layout Options

To address the above issue, we have explored two options as below;

Option 1: Relocate the proposed subdivision spine road by around 2m to the northwest so that it better aligned

with Jarnac Boulevard. This option would require a small adjustment to the boundaries of proposed Lot

38 and Lot 39.




Option 2: Relocate the proposed subdivision spine road to the southeast boundary of the proposed Living 1 zone

and the proposed Open Space zone to create a new T-junction intersection with Buchanans Road

approximately 90m southeast of the existing Buchanans-Jarnac T-junction. This option would require

a major redesign of the proposed subdivision layout.

CCC Consultation

Concept sketches of the two options were prepared and emailed to Mr Calvert for review and consideration prior to

a meeting with him and Mr Chen on Wednesday 19 November 2014. The main points of the meeting were as follows;

1. In principle, CCC favoured the Option 2 off-set T-junction option over the Option 1 signalised cross junction

option for the following reasons;

a. CCC considers that future extension of the plan change area road network through to Roberts Road

as per the ODP is likely to be many years away (if it proceeds at all).

b. In the event that the Roberts Road connection was never established (or not established for many

years), this would effectively result in a residential cul de sac served by a signalised intersection - a

situation that CCC does not favour for a number of reasons including that it might be seen to set a

precedent and lead to other residential culs de sac wanting their junctions signalised.

c. The off-set T junction option better promotes the road hierarchy, and protects levels of service on

the minor arterial route of Buchanans Road.

d. The T junction option will be far less costly to construct for the developer.

2. Mr Calvert and Mr Chen acknowledged that the offset T junctions would not meet the 150m intersection

separation standard of the Council's Infrastructure Design Standard (IDS), but considered that the 90m offset

(approx) that could be achieved would be acceptable.

3. Mr Calvert and Mr Chen acknowledged the clients concerns about potential lack of efficiency having

properties on one side of the road only with the revised internal road layout associated with the T junction

option, and suggested a reduced legal road width of 16-17m with a 9m carriageway through the subdivision

that would potentially yield more land to develop into residential sections.

4. While the off-set T junction road layout differs slightly from the ODP layout, Mr Calvert and Mr Chen indicated

that Council planners had already intimated that there were unlikely to be major issues associated with such

a change and they would attempt to seek clarification/confirmation on that issue.

Mr Calvert later clarified point 4 above, saying that he had spoken to one of the Council planners (Mr Sean Ward)

after the meeting regarding the issue of the potential non-compliance of the plan with the ODP and Mr Ward had

been non-committal as it would be the subject of the RC application as a variation to the ODP which would form part

of the application. Mr Calvert advised that Mr Ward had also commented that the planners would seek comments

from the Asset & Network Planning team to assist them in their assessment of a consent application, and would

normally follow that advice. In other words, it appears that Mr Ward was suggesting that processing a subdivision




application with a road layout that deviated from the ODP would most likely not be an issue if Mr Calvert and/or Mr

Chen were agreeable to the proposed road layout.

Road Layout Option Issues

As discussed in the meeting with yourself and Mr George Haddow on Tuesday 2 December 2014, I can see the

merits of the off-set T-junction option (Option 2) compared to a signalised cross junction (Option 1) in terms of road

safety, maintaining current levels of service on Buchanans Road and also for the reason that the intersection

construction costs for Option 2 would most likely be significantly less than for Option 1. I accept the client's position

however, that Option 2 would result in significant inconvenience and cost to them associated with redesigning the

subdivision layout and would also result in a less efficient and/or less desirable subdivision layout even with the

reduced road widths suggested by Mr Calvert and Mr Chen. In addition, I acknowledge the client's frustration in that

they have already committed significant time and effort progressing the design of the subdivision proposal on the

basis of the ODP and Mr Chen's earlier advice that the CCC would prefer a signalised cross junction on Buchanans

Road as opposed to the large roundabout for which provision had already been made at the Buchanans-Jarnac T

junction.

I also fully agree with you and the client that there are insufficient assurances in the comments of Mr Calvert, Mr

Chen or Mr Ward that Council would accept and support the deviation from the ODP. As you have pointed out, the

subdivision application carries a risk of notification and any deviation from the ODP may well result in submissions

in opposition from other parties. On this matter, and also in relation to the reduced road widths for Option 2 suggested

by Mr Calvert and Mr Chen, I understand that a significant part of the ongoing issues with the stalled Noble Village

development relate to neighbours’ concerns over reduced road widths and/or departures from the Councils road

design standards.

After discussing the issue of timing relating to development of the wider ODP area with yourself and the client,

becoming aware that the Noble Village developers are actively trying to reinstate and complete that project and also

becoming aware of the consented football academy development north of Noble Village, I do not necessarily accept

Mr Calvert and Mr Chen's position in regard to point 1a earlier. It would appear that there may well be demand to

fully develop the ODP area for residential land if the Noble Village and football academy developments proceed,

particularly if the proposed commercial elements within Noble Village are fully developed. Furthermore, development

of the commercial elements of Noble Village and the football academy will result in higher vehicle demand flows

between the proposed subdivision spine road and Jarnac Boulevard.

For the above reasons, I support the Option 1 road alignment and the creation of a cross junction at the existing

Buchanans-Jarnac T junction. To this effect I note that the proposed subdivision layout plan has now been amended

to relocate the spine road approximately 2m to the northwest so as to now provide a better alignment with Jarnac

Boulevard.




Cross Junction Intersection Layout Concept

Urbis has not been briefed to prepare a final detailed intersection design plan, and this work would best be undertaken

by specialist consultants with experience in that field and in consultation with Council staff. For the purpose of this

assessment however, a concept sketch has been prepared on the amended subdivision layout plan to show how the

existing Buchanans-Jarnac T junction might be converted to a cross junction that incorporated the proposed new

subdivision spine road as shown in Figure 2 below.

Features of the concept layout include;

• Shared 4.5-5.0m wide through / left turn lanes on each approach.

• Dedicated 2.5-3.0m wide by 20-25m long right turn lanes on each approach. In order to correctly align the

right turn lanes so that they oppose each other, it would be necessary to reduce the width of the existing 4m

wide solid median on Jarnac Boulevard. This would require the removal or relocation of three small trees

and an existing light pole.

• Single 4.5-5.5m wide departure lanes on each leg of the intersection.

Figure 2: Cross Junction Intersection Layout Concept




Intersection Control

As noted earlier, the previous TIA prepared by Urbis considered potential effects associated with residential

development of around 60 dwellings on the PC80 site as well as full residential development (around 255 dwellings)

of the ODP area. The TIA presented the results of SIDRA analysis for a number of scenarios at the Buchanans-

Jarnac intersection that included existing/surveyed demand flows, estimated future 2017 base demand flows and

future 2017 base + development demand flows for both the PC80 site and the entire ODP area. SIDRA analysis

was also undertaken to compare the performance of the intersection under a priority cross junction control and a

roundabout control.

On the basis of the SIDRA analysis, the TIA concluded that that a priority control at the cross junction intersection of

Jarnac Boulevard and the proposed new spine road with Buchanans Road could efficiently and safely accommodate

traffic associated with development of the then proposed 60 lot residential development within the PC80 application

site, however development of the wider South of Masham ODP area may require the installation of a roundabout or

traffic signals to safely and efficiently accommodate the greater levels of traffic that would be generated.

There has been a newer version of SIDRA released since the TIA was completed, and the current subdivision

proposal is for only 39 residential allotments (compared to the previous 60 allotments). For these reasons, SIDRA

analysis was repeated for the current proposal. Appendix A provides summary tables of the SIDRA analysis, showing

volumes (vehicles per hour), control delay (seconds), level of service (LOS) and 95th percentile queue lengths

(metres) during the AM and PM peak periods for the following scenarios;

a) Existing Buchanans-Jarnac intersection - surveyed June 2012 volumes.

b) Existing Buchanans-Jarnac intersection - estimated future 2017 base volumes.

c) Proposed cross junction intersection (priority control) - estimated future 2017 base volumes plus

development traffic (39 lots).

d) Proposed cross junction intersection (priority control) - estimated future 2017 base volumes plus 60 lot

development (ie full development of the PC80 area).

e) Proposed cross junction intersection (priority control) - estimated future 2017 base volumes plus 100 lot

development (sensitivity test of further development extending into the South of Masham area).

While it is recognised that the future 2017 base year is now only two years into the future, it was decided for simplicity

to leave it as that used in the original traffic assessment. As before, the traffic volumes used in the SIDRA analysis

were based on a nominal 5% heavy vehicle component for all legs and movements, and the distribution of site

generated traffic was assumed on the basis of surveyed distribution of existing Delamain subdivision traffic recorded

in the June 2012 surveys (along with a small allowance for some through traffic between the Delamain subdivision

and the current proposal). Gap acceptance and follow up headway values used in the SIDRA analysis were taken

from Austroads Guide to Road Design Part 4A: Unsignalised and Signalised Intersections (Oct 2010), except for the

right turn movements from the side roads in the cross junction scenarios whereby Austroads indicated values of 5




seconds (gap acceptance) and 3 seconds (follow up headway) should be used however it was decided to

conservatively adopt higher values of 7 seconds and 4 seconds in recognition that these movements also had to

yield to through traffic from the opposite side road as well as traffic on Buchanans Road.

Based on the SIDRA results it is noted that:

a) The current (2012) Buchanans-Jarnac priority controlled T-junction intersection operates with very modest

delays of 8.0 seconds or less on all movements during both the AM and PM peak, with corresponding good

levels of service (LOS A) and negligible queuing.

b) Under the estimated future 2017 base scenario, the intersection will continue to operate with modest delays

and levels of service LOS A on almost all movements during both the AM and PM peak with the exception

of the right turn movement from Jarnac Boulevard during the PM peak period where average delays increase

to 12.1 seconds with a corresponding level of service LOS B.

Overall, the SIDRA analysis demonstrates that the existing T-junction intersection will continue to operate with a

good level of service over the next couple of years.

In terms of the future 39-lot development scenario:

c) Converting the Buchanans-Jarnac intersection to a priority controlled cross-junction (based on the concept

layout shown in Figure 2) and introducing additional development traffic associated with the proposed 39

residential allotments further increases delays on the right turn movement from Jarnac Boulevard during the

PM peak period to 25.6 seconds with a corresponding decrease in level of service to LOS D.

During the AM peak period, delays on the right turn movement from Jarnac Boulevard also increase to 17.0

seconds with a corresponding decrease in level of service to LOS C.

Owing to slightly higher right turn volumes, and the requirement to yield to the higher left turn volume out of

Jarnac Boulevard as well as Buchanans Road traffic, the right turn movement out of the proposed new road

will experience slightly higher delays during both the AM and PM peak period of 31.9 seconds and 32.9

seconds respectively with a corresponding level of service LOS D.

All other movements will experience modest delays of less than 10 seconds and corresponding levels of

service LOS A.

Overall, and noting that the adoption of conservatively high right turn gap acceptance and follow up headway

values used in the SIDRA analysis, the delays and levels of service noted above are considered to be

acceptable and it is considered that the intersection could operate efficiently without the need to install traffic

signals immediately.

It is acknowledged that priority cross junction intersections generally have a poorer safety performance

compared to other intersection types (alignment and/or control). However, in this instance:

• The modest delays indicated in the SIDRA analysis suggest that it will be less likely for drivers to become

frustrated with long delays turning out of the side roads and take unnecessary risks as a result.




• Furthermore, the estimated volumes on the through movements between the Delamain subdivision and

the current proposal are very modest, and drivers undertaking these manoeuvres are most likely to be

residents of the area who are familiar with the road environment at this location.

• Sight lines along Buchanans Road from Jarnac Boulevard and the proposed new road are also excellent,

and the SIDRA queue results indicate that it would be very rare for the adjacent approach lane to be

occupied by another vehicle such that visibility would be impeded (note that the auxiliary turn lanes on

the side road approaches are suggested for alignment purposes, and are probably not required for

capacity).

• A rudimentary analysis of potential safety performance of a priority controlled cross junction versus two

off-set priority controlled T junctions was undertaken using the crash prediction models for high speed

(ie 70 km/h or greater) priority junctions provided in the NZTA Economic Evaluation Manual (EEM), and

the results (see Appendix B) indicated that, under the estimated future 2017 base volume scenario plus

traffic associated with the proposed 39 lot residential subdivision development, a priority controlled cross

junction would only have a marginally higher crash rate (1.0 crashes per 5 years) than an off-set priority

controlled T junction arrangement (0.7 crashes per 5 years).

• Side road approach speeds could be controlled through the installation of road humps or textured surface

threshold treatments on the two side roads within 50m of their intersections with Buchanans Road.

• Consideration could be given to lowering the speed limit on Buchanans Road, however it should be

noted that the EEM crash prediction model analysis was undertaken on the basis of the existing 70 km/h

speed limit remaining in place.

For the above reasons, it is considered that the proposed cross junction intersection could operate both

efficiently and safely under a priority control with the development of 39 residential allotments on the south

side of Buchanans Road as proposed.

The question then is at what stage would the installation of traffic signals be required for efficiency and/or safety

reasons? As noted above, SIDRA analysis was undertaken on two future scenarios (d and e earlier) whereby the

proposed new road served a total of 60 residential allotments and 100 residential allotments respectively.

d) Under the 60 lot development scenario, delays on the right turn movement out of the proposed new road just

exceeded 35.0 seconds in the AM peak period (SIDRA results indicated 35.3 seconds) thereby triggering a

reduction in level of service from LOS D previously to LOS E. During the PM peak, delays on this movement

increased to 34.0 seconds and thus the level of service remained at LOS D.

e) Under the 100 lot development scenario, delays on the right turn movement out of the proposed new road

exceeded 35.0 seconds (LOS E) during both the AM and PM peak periods.

Other than the right turn movement out of the proposed new road, the increased volumes in both of these scenarios

had little impact on average delays, levels of service and/or queue lengths compared to the proposed development

scenario with 39 residential allotments.




The 2008-2018 version of the Canterbury Regional Land Transport Strategy (RLTS) previously set levels of service

targets for the strategic urban road network outside and including the Christchurch ring road locations to operate at

a minimum of LOS D during peak times and LOS C during other times, however reference to these targets has since

been removed from the current RLTS (2012-2042). Nevertheless, the previous RLTS LOS targets are still commonly

used as guideline upper limits. On this basis, it is considered that the proposed new cross junction intersection would

continue to operate with acceptable levels of service under a priority control up to the development of 60 residential

allotments/dwellings on the PC80 area.

Based on the above, it is considered that the previously proposed Stage 1 limit of 60 residential allotments be adopted

as the trigger for the installation of traffic signals at the proposed new cross junction intersection or, at least, be

adopted as a trigger whereby any development beyond 60 allotments requires a detailed traffic assessment to

determine whether the installation of traffic signals is warranted or not. What is important to note at this stage is that

the Council’s suggestion of offset T intersections could result in capacity issues at a later date that would not be

readily resolvable.

Conclusion

The Council adopted a plan change for the Luney site based on an ODP with the spine road through the 39-lot site

aligning with Jarnac Boulevard and has confirmed this approach by inclusion of the same ODP into the Replacement

District Plan along with rezoning the area for residential purposes. The logic of this is that the spine road would

continue further north through Delamain and Noble developments, and would also now connect with the football

academy on the northern side of Yaldhurst Road.

The low traffic volumes expected by the Council to be generated by the various neighbouring developments onto the

side roads connecting to Buchanans Road means that the Council now prefers an offset T-junction arrangement for

the two side roads. This has implications in terms of section yield of the Luney 39-lot site and also long term

connectivity to the north. It also departs from the proposed ODP and the intersection offset does not meet the

Council’s own design standards.

We remain of the view that the proposed spine road through the Luney site should align with Jarnac Boulevard to

create a cross junction intersection. In the short to medium term the expected traffic volumes on the two side roads

to this intersection are unlikely to justify signalisation. Concerns with the operation of a priority control cross junction

in a semi-rural speed environment are noted, however a rudimentary crash prediction analysis indicates relatively

low crash rates for both the off-set T junction and cross junction options, and we consider that any safety issues can

be addressed through control of the approach speeds on the two side roads and/or possibly lowering the speed limit

on Buchanans Road.

Retaining a cross junction configuration means that should development of the various subdivisions get to a point

where side road delays become unacceptable, then the intersection could be signalised at a point in the future. Such

capacity issues would be more difficult to resolve with an off-set T junction arrangement such as that now being

suggested by the Council.




We therefore recommend the following;

1. The amended subdivision layout plan provided during the course of this assessment be submitted to Council

to replace the originally lodged subdivision layout plan;

2. The applicant engages specialist consultants to undertake the detailed design of a cross junction intersection

at the existing Buchanans-Jarnac intersection generally in accordance with the concept sketch prided in

Figure 2 of this report, and in consultation with Council; and,

3. The suggested cross junction be designed to operate initially (at least allowing for the development of the

proposed 39 residential allotments) on a priority control basis, but constructed such that it can be easily

converted to a signalised control at some point in the future, determined by a trigger condition attached to

this and/or subsequent subdivision consents or by inclusion of an appropriately worded rule in PC80.

Please do not hesitate to contact me on 03 963 8725; or alternatively email [email protected] if you have

any questions.

Yours faithfully,

URBIS TPD LIMITED

Wayne Gallot

Transportation Planner




APPENDIX A

SIDRA Summary Tables

EXISTING 2012 SURVEYED VOLUMES - AM PEAK

Lt Th Lt Rt Th Rt

Gap - - 5 5 - 4

H/way - - 3 3 - 2

Volume 5 236 81 7 177 29

Delay 6.4 0.0 6.1 7.4 0.0 7.2

LOS A A A A A A

Queue 0 0 3 0 0 1

FUTURE 2017 BASE VOLUMES - AM PEAK

Lt Th Lt Rt Th Rt

Gap - - 5 5 - 4

H/way - - 3 3 - 2

Volume 20 293 319 28 233 114

Delay 6.4 0.0 7.9 9.6 0.0 7.6

LOS A A A A A A

Queue 0 0 17 1 0 3

FUTURE 2017 BASE VOLUMES + DEVELOPMENT (39 LOTS) - AM PEAK

Lt Th Rt Lt Th Rt Lt Th Rt Lt Th Rt

Gap - - 4 5 5 7 - - 4 5 5 7

H/way - - 2 3 3 4 - - 2 3 3 4

Volume 20 293 1 319 1 28 7 233 114 5 4 20

Delay 6.4 0.0 6.4 7.9 7.0 17.0 5.6 0.0 7.7 8.5 7.6 31.9

LOS A A A A A C A A A A A D

Queue 0 0 0 18 18 3 0 0 3 0 0 4

FUTURE 2017 BASE VOLUMES + DEVELOPMENT (60 LOTS) - AM PEAK


Gap - - 4 5 5 7 - - 4 5 5 7

H/way - - 2 3 3 4 - - 2 3 3 4

Volume 20 293 2 319 2 28 12 233 114 7 6 32

Delay 6.4 0.0 6.4 8.0 7.0 17.1 5.6 0.0 7.7 8.6 7.7 35.3

LOS A A A A A C A A A A A E

Queue 0 0 0 18 18 3 0 0 3 1 1 6


Gap - - 4 5 5 7 - - 4 5 5 7

H/way - - 2 3 3 4 - - 2 3 3 4

Volume 20 293 3 319 3 28 19 233 114 12 10 53

Delay 6.4 0.0 6.4 8.0 7.0 17.5 5.6 0.0 7.7 8.7 7.8 41.5

LOS A A A A A C A A A A A E

Queue 0 0 0 18 18 3 0 0 3 1 1 12

Buchanans E New Road S

Buchanans W Jarnac N Buchanans E New Road S


Buchanans W Jarnac N Buchanans E

Buchanans W Jarnac N

Buchanans EBuchanans W Jarnac N




EXISTING 2012 SURVEYED VOLUMES - PM PEAK

Lt Th Lt Rt Th Rt

Gap - - 5 5 - 4

H/way - - 3 3 - 2

Volume 12 165 50 12 268 75

Delay 6.4 0.0 5.6 8.0 0.0 7.0

LOS A A A A A A

Queue 0 0 1 1 0 2

FUTURE 2017 BASE VOLUMES - PM PEAK

Lt Th Lt Rt Th Rt

Gap - - 5 5 - 4

H/way - - 3 3 - 2

Volume 39 205 161 39 353 242

Delay 6.4 0.0 6.4 12.1 0.0 7.4

LOS A A A B A A

Queue 0 0 5 3 0 7

FUTURE 2017 BASE VOLUMES + DEVELOPMENT (39 LOTS) - PM PEAK


Gap - - 4 5 5 7 - - 4 5 5 7

H/way - - 2 3 3 4 - - 2 3 3 4

Volume 39 205 5 161 3 39 16 353 242 3 2 10

Delay 6.4 0.0 7.0 6.3 5.3 25.6 5.6 0.0 7.5 9.9 9.0 32.9

LOS A A A A A D A A A A A D

Queue 0 0 0 6 6 6 0 0 7 0 0 2

FUTURE 2017 BASE VOLUMES + DEVELOPMENT (60 LOTS) - PM PEAK


Gap - - 4 5 5 7 - - 4 5 5 7

H/way - - 2 3 3 4 - - 2 3 3 4

Volume 39 205 7 161 4 39 25 353 242 5 2 16

Delay 6.4 0.0 7.0 6.3 5.4 25.8 5.6 0.0 7.5 9.4 8.5 34.0

LOS A A A A A D A A A A A D

Queue 0 0 0 6 6 6 0 0 7 0 0 3


Gap - - 4 5 5 7 - - 4 5 5 7

H/way - - 2 3 3 4 - - 2 3 3 4

Volume 39 205 12 161 7 39 43 353 242 8 4 26

Delay 6.4 0.0 7.1 6.5 5.5 26.5 5.6 0.0 7.5 9.8 8.9 38.1

LOS A A A A A D A A A A A E

Queue 0 0 0 6 6 6 0 0 7 1 1 5









APPENDIX B

Crash Prediction Model Calculations

Note: For the purpose of this analysis, the estimated daily volumes were derived by averaging the AM and PM peak volumes

and then dividing that figure by the assumed peak to daily factor.

Sight distance deficiency (Vd) 1

Major road mean speed (Sl) 70

Assumed Peak to Daily Factor 0.14

Rt Th Lt Rt Th Lt Rt Th Lt Rt Th Lt

q1 q2 q3 q4 q5 q6 q7 q8 q9 q10 q11 q12

Estimated AM Peak 28 1 319 114 233 7 20 4 5 1 293 20

Estimated PM Peak 39 3 161 242 353 16 10 2 3 5 205 39

Estimated Daily (rounded to nearest 10) 240 10 1710 1270 2090 80 110 20 30 20 1780 210

Crossing – hit from right (Major road

approaches only)

A = 1.15 × 10-4 × q20.60 × q50.40

0.0097 0.0139 0.0236

Crossing – hit from right (Minor road

approaches only)

A = 1.97 × 10-4 × q20.40 × q110.44

0.0133 0.0189 0.0322

Right turning and following vehicle (Major

Road approaches only)

A = 1.04 × 10-6 × q40.36 × q51.08 × 0.22

0.0116 0.0022 0.0137

Other (Major road approaches only)

A = 1.09 × 10-4 × (q4 + q5 + q6)0.76 0.0531 0.0353 0.0884

Other (Minor road approaches only)

A = 3.30 × 10-3 × (q1 + q2 + q3)0.27 0.0256 0.0130 0.0385

0.1133 0.0832 0.1965 Crashes per year

1.0 Crashes per 5 years

Rt Lt Rt Th Th Lt Rt Lt Rt Th Th Lt

q1 q2 q3 q4 q5 q6 q1 q2 q3 q4 q5 q6

Estimated AM Peak 28 320 118 238 294 20 20 9 2 612 347 7

Estimated PM Peak 39 164 244 356 210 39 10 5 8 366 595 16

Estimated Daily (rounded to nearest 10) 240 1730 1290 2120 1800 210 110 50 40 3490 3360 80

Crossing – Vehicle turning (Major road

approach to right of side road)

A = 5.29 × 10-6 × q11.33× q50.15 ×Vd0.33

0.0238 0.0093 0.0331

Right-turning and following vehicle (Major

road approach to left of side road)

A = 5.29 × 10-27 × q30.46× q40.67 × Sl11.0

0.0048 0.0013 0.0061

Other (Major road approach to right of side

road)

A = 1.59 × 10-5 × (q5 + q6)0.91

0.0161 0.0263 0.0424

Other (Major road approach to left of side

road)

A = 2.99 × 10-4 × (q3 + q4)0.51

0.0189 0.0193 0.0382

Other (Side road approach)

A = 1.47 × 10-2 × (q1 + q2)-0.02 0.0126 0.0133 0.0259

0.0763 0.0695 0.1458 Crashes per year

0.7 Crashes per 5 years

Buchanans EJarnac Buchanans E Buchanans W New Road Buchanans W

Priority Cross Junction

Off-Set Priority T Junctions

Jarnac Buchanans E New Road Buchanans W

819006 150127 buchanans road v2 subdivision (intersection...

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