Tinwald Corridor Study - Ashburton · DATE: JAN 2015 DATE:FEB 2015 DATE: FEB 2015 DATE: Revision...

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Programme Business Case

Tinwald Corridor Study

10 March 2015

Approval

PREPARED BY: REVIEWED BY: ENDORSED BY: APPROVED BY:

Callum Wood

With input from

Neil McCann (ADC)

Stuart Woods Colin Knaggs

Ian McCabe – P&I

Canterbury BUDMT

ADC

The Transport Agency

PROJECT MANAGER TRANSPORTATION PLANNING

MANAGER

STAKEHOLDER PROJECT

SPONSORS

DELEGATED AUTHORITY -

STAKEHOLDERS

DATE: JAN 2015 DATE:FEB 2015 DATE: FEB 2015 DATE:

Revision Status*

REVISION NUMBER: IMPLEMENTATION DATE: SUMMARY OF REVISION

A 27/01/15 Draft for internal comment

B 19/02/15 Draft for Transport Agency/ BUDMT comment

C 27/02/15 Draft for ADC and working group comment

D 10/03/15 Draft for stakeholder comment and ADC

endorsement

Delete Revision Status Table on production of final version

Template Status

REVISION NUMBER: IMPLEMENTATION DATE: SUMMARY OF REVISION

Contents

Glossary of Terms ................................................................................................................................. 5

Executive Summary .............................................................................................................................. 7

PART A – THE STRATEGIC CASE ....................................................................................................... 8

1 Introduction .................................................................................................................................... 8

2 Partners and Key Stakeholders .................................................................................................. 11

2.1 Project Partners..................................................................................................................... 11

2.2 Key Stakeholders .................................................................................................................. 11

3 Strategic Assessment - Outlining the Need for Investment .................................................... 13

3.1 Defining the Problem ............................................................................................................. 13

3.2 The Benefits of Investment ................................................................................................... 14

4 Strategic Context ......................................................................................................................... 15

4.1 Organisational Outcomes, Impacts and Objectives .............................................................. 15

4.2 Alignment to Existing Strategies/Organisational Goals ........................................................ 16

4.3 Context with comparative networks and issues .................................................................... 16

5 Changes/Updates to the Strategic Case.................................................................................... 17

5.1 New Supermarket at South Street ........................................................................................ 17

5.2 New bridge designation ......................................................................................................... 17

5.3 Existing Strategic Assessment .............................................................................................. 17

PART B – DEVELOPING THE PROGRAMME .................................................................................... 18

6 Programme Context..................................................................................................................... 18

6.1 Geographical & Environmental Context ................................................................................ 18

6.2 Social and Community Context ............................................................................................. 18

6.3 Economic Context ................................................................................................................. 19

7 Demonstrating the Need for Investment ................................................................................... 20

7.1 Problems and Opportunities .................................................................................................. 20

7.2 Issues and Constraints .......................................................................................................... 20

7.3 Delay ..................................................................................................................................... 21

8 Stakeholders ................................................................................................................................ 23

8.1 Consultation and Communication Approach ......................................................................... 23

8.3 Professional Engagement Process ....................................................................................... 24

8.4 Consultation Feedback ......................................................................................................... 24

8.5 Next steps ............................................................................................................................. 25

8.6 Media ..................................................................................................................................... 25

9 Alternative and Option Assessment .......................................................................................... 25

9.1 Background ........................................................................................................................... 25

9.2 Initial assessment of Alternatives .......................................................................................... 25

9.3 Option discussion .................................................................................................................. 26

9.4 Assessment of options on Intersection Delay ....................................................................... 27

9.5 Discussion on second bridge (2026) key results .................................................................. 29

9.6 Discussion ............................................................................................................................. 29

9.7 Constraints and Dependencies ............................................................................................. 29

9.8 Key stakeholder feedback on alternatives and options ........................................................ 29

10 Programme Options Development and Assessment .......................................................... 31

10.1 Programme Development ..................................................................................................... 31

10.2 Process ................................................................................................................................. 31

10.3 Typical treatment example sketches ..................................................................................... 34

10.4 Do-Minimum Option .............................................................................................................. 35

10.5 Programme Assessment ....................................................................................................... 35

10.6 Cyclist and pedestrian specific comments ............................................................................ 36

10.7 Qualitative Assessment to deliver the benefits listed within the ILM .................................... 36

10.8 Discussion on the option results ........................................................................................... 37

11 Recommended Programme ................................................................................................... 39

11.1 Programme Overview ........................................................................................................... 39

11.2 Programme Implementation Strategy & Trigger Points ........................................................ 40

12 Recommended Programme – Assessment .......................................................................... 42

12.1 Programme Outcomes .......................................................................................................... 42

12.2 Programme Risk ................................................................................................................... 43

12.3 Value for Money .................................................................................................................... 43

12.4 Assessment Profile ............................................................................................................... 43

13 Programme Financial Case .................................................................................................... 44

13.1 Indicative cost........................................................................................................................ 44

13.2 Funding arrangements .......................................................................................................... 44

13.3 AffoRoadability ........................................................................ Error! Bookmark not defined.

PART C – DELIVERING & MONITORING THE PROGRAMME ......................................................... 45

14 Management Case ................................................................................................................... 45

14.1 Programme Governance and Reporting ............................................................................... 45

14.2 Stakeholder Engagement and Communications Plan .......................................................... 45

14.3 Programme Performance and Review .................................................................................. 45

Appendix A - Investment Logic Map .................................................................................................... I

Appendix B – Benefits Map ................................................................................................................. III

Appendix C – Location Map ................................................................................................................IV

Appendix D – Background Evidence to Needs ..................................................................................V

Appendix E – Background information to development of options .............................................VIII

Appendix F – Possible Treatments Discussion ...............................................................................XII

Appendix G – 2026 Level of service and actual volumes ..............................................................XIII

Glossary of Terms

Abbreviation Term

AADT Average annual daily traffic

ADC Ashburton District Council

AEE Assessment of Environmental Effects

BCR Benefit-Cost Ratio

CAPEX Capital Expenditure

CBD Central Business District

CRLTS Canterbury Regional Land Transport Strategy

CVIU Commercial Vehicles Investigation Unit

D&C Design and Construct

DE Design Estimate

EEM Economic Evaluation Manual

EIR Environmental Impact Report

EOI Expression of Interest

EPA Environmental Protection Agency

FYRR First Year Rate of Return

GPS Government Policy Statement

HCV Heavy Commercial Vehicle

HNO Highways and Network Operations

HPT Historical Places Trust

ILM Investment Logic Map

IRS Investment and Revenue Strategy

ITS Intelligent Transport Systems

KPI Key Performance Indicator

LGA Local Government Act 2002

LTMA Land Transport Management Act

LTP Long Term Plan

MOU Memorandum of Understanding

NLTF National Land Transport Fund

NLTP National Land Transport Programme

NOR Notice of Requirement

NPC Net Present Cost

NZCID New Zealand Council for Infrastructure Development

NZTA The New Zealand Transport Agency (The Transport Agency)

Abbreviation Term

NZTS New Zealand Transport Strategy

OPEX Operating Expenditure

PBC Programme Business Case

P&I Planning and Investment

PI Performance Indicator

PMS Project Management Services

PoPS Portfolio Procurement Strategy

PPFM Planning Programming and Funding Manual

PPM Principal Project Manager

PPP Public Private Partnership

PT Public Transport

PWA Public Works Act

RAMM Road Assessment and Maintenance Management

RFP Request for Proposal

RLT Regional Land Transport

RLTS Regional Land Transport Strategy

RMA Resource Management Act

RoNS Road of National Significance

SAR Scheme Assessment Report

SE Scheme Estimate

SH(#) State Highway (number)

SHAMP State Highway Activity Management Plan

SOI Statement of Intent

SSEMP Site Specific Environmental Management Plan

TA Territorial Authority

TDM Traffic Demand Management

TOC Total Outturn Cost

VAC Value Assurance Committee (formerly SSRC)

VMS Variable Messages Sign

WEBs Wider Economic Benefits

Executive Summary

Part A: The Strategic Case

A Strategic Case was finalised in July 2014 following work on this project in 2013. This report confirms

the strategic context problems and benefits of a response identified in the Strategic Case.

Ashburton District Council (ADC) and the NZ Transport Agency (Transport Agency) are joint project

partners in this development of this Programme Business Case for the Tinwald Corridor (Ashburton River

to Maronan Road).

Tinwald is located in the southern part of Ashburton It is experiencing good growth in population and

it has a future development plan that is expected to accommodate for and encourage this growth.

A key driver for pursuing the strategic case is the current delays experienced for side road traffic at

most State Highway intersections along the corridor, and the corresponding loss of level of service are

predicted in 2016 particularly in morning peaks and worsening in 2026.

The second key driver is the severance issue born from having the state highway pass through the

middle of the Tinwald area. Pedestrian and cycling links need to be considered as the population grows

and areas are developed. The impact of cross movements due to severance is expected to have an effect

on the overall transport network performance if not planned for.

Investment is needed in the short term to enable solutions that will address delays at all intersections

and severance.

Part B: Developing the Programme

The options and programme recommended have been developed to address the objectives, issues and

problems identified in the benefit statement. In the longer term the Ashburton River Urban 2nd

bridge

will provide significant relief to most of the identified issues. A traffic model has been used that predicts

a variety of benefits (some notable and positive) for a range of different treatments depending on the

intersection.

All programmes investigated have similar strategic responses and relatively very close benefits. All have

a mixture of safety, severance and local road components. Many could support walkways and cycle-

ways.

Timing of any investment should be managed to recognise that while some areas of the Tinwald corridor

currently aren’t performing well for some periods of the day, most isn’t significantly compromised yet.

Notwithstanding, analysis has indicated that within 10 years this changes significantly, and therefore

investigation phases should continue with a view that any interventions (physical works) can be

introduced in a timely fashion.

An assessment profile of M/M/L has been determined for the recommended programme using the

Transport Agency’s Investment Assessment Framework.

Recommended Programme

The recommended programme has been developed internally and a timescale of 10 years has been used

due to the impacts being experienced. Activities are timed for when they are forecast to be needed.

The early activities include channelisation improvements at a number of key intersections that will assist

immediately with delay issues and look to include any needs for pedestrians and cyclists.

Medium to long term activities comprise of intersection improvements, cycleway and pedestrian

crossings and analysis of where best sited, intersection priority and potential speed limit changes.

A number of activities are proposed to be carried through to an Indicative Business Case for further

development. These are:

for a roundabout at Graham and other key intersection improvements on SH1 (Wilkin, Lagmhor and

Carters)

The longer term activities will be included as part of an internal Transport Agency review and update of

the programme business case in later phases.

PART A – THE STRATEGIC CASE

1 Introduction

This programme business case (PBC) verifies the preferred programme of works along the traffic

corridor of SH1 in Tinwald, Ashburton that responds to the case for change outlined in the

Strategic Case. The proposal principally seeks to address a problem of safe and effective access

to SH1 for side road traffic in Tinwald.

Growth in the District with significant residential development both sides of the highway in

Tinwald, commercial centres along and at the end of the Tinwald corridor and general state

highway traffic volumes increasing are all contributing to efficiency and safety issues.

An earlier programme to address State Highway issues through Tinwald was identified as part

of the programme of works outlined in the Ashburton Transportation Study, 2008, (a joint study

commissioned by the New Zealand Transport Agency, the “Transport Agency” and Ashburton

District Council). Some have been implemented, but the remainder now need revisiting due to

the changing circumstance and analysis.

A Strategic Case was finalised in July 2014. It has not been formally endorsed by the HNO’s VAC,

but the approval process for strategic cases was unclear at the time, and it is expected the

programme business case will go through for VAC approval. The strategic case is verbally

supported by regional P&I, and the region BUDMT.

Part A of this business case revisits the strategic case and reconfirms the case for investment

following some further evidence collection, analysis and workshops with the key stakeholders

to support the programme development.

Part B discusses the development of the programme of works considered, the recommended

programme and its financial case

This PBC is supported by the following key documents:

Strategic Case – Tinwald Corridor Study, July 2014 – The Transport Agency and ADC

ADC District Plan designation (No. 208 ) of new Ashburton River 2nd

Urban Bridge

corridor , 2014

Tinwald SH1: Options Assessment (Traffic Modelling); Nov 2014; Opus

Tinwald Deficiency Assessment (Traffic Modelling); Oct 2014; Opus

A location map is shown in Figure 1 over page.

Figure 1: Tinwald Corridor location map

2 Partners and Key Stakeholders

Ashburton District Council (ADC) and the Transport Agency are joint project partners in this

development of this PBC for the Tinwald Corridor. Key stakeholders include Tinwald businesses,

the local Road Transport Association, Schools, Cycle clubs, Police, the developer community,

key Council staff and Councillors.

2.1 Project Partners

Ashburton District Council and the Transport Agency are jointly leading the Tinwald Corridor

proposal. They are partners in this process.

NZ Transport Agency: The Transport Agency is responsible for the planning, management and

operation of state highways through the Highways and Network Operations Group. This group

responds to the strategic direction of the Transport Agency as defined by the Governments

Policy Statement (GPS) for Land Transport Funding and the Statement of Intent.

Ashburton District Council: Ashburton District Council (ADC) is responsible for the land use

development planning in the Tinwald area and the local road transport network through its

district plan. Integration of the transport required to service land uses in the area and the

transport system is a key consideration for district councils.

2.2 Key Stakeholders

A number of key stakeholders external to ADC and the Transport Agency also have influence on

the project outcomes. They have been identified through discussion with Council staff and

through their engagement in previous processes such as the Ashburton Transport Study and

the Council’s Long Term Plan submissions. These organisations met as part of the workshops

held in Ashburton in 2014 for the Programme Business Case (PBC). Their anticipated role, area

of expertise and interest in the project is summarised below:

Ashburton Business Association: The business community will be interested to

represent the potential traffic related impacts on both the immediately adjacent and

affected businesses, as well as the wider Ashburton business community. They are a

valuable contributor in understanding the nature and scale of the problem and the

potential benefits of investment in the area.

Local Businesses and Residents: These stakeholders are the most directly affected

groups. There is one local residents group, the Ashburton Citizens Association which

represents residents from across all Ashburton. There is no local business group

representing the immediately affected businesses.

Mid-Canterbury Road Transport Association: The working knowledge of the day-to-

day operation of the transport network as used by the freight industry, as understood

though their collective membership of operators, is highly valuable in understanding

the nature and scale of the problem and the potential benefits of investment in the area.

Canterbury AA: The Canterbury AA regularly provides useful input to transport

proposals, representing their membership of private vehicle owners. The AA can be a

very useful contributor and partner in seeking out the views of its membership through

their communication channels. This could be highly valuable in understanding the

nature and scale of the problem and the potential benefits of investment in the area.

Lake Hood Developments: The Lake Hood development is a significant residential

subdivision (470ha) located at Lake Hood, about 13 km south-east of SH1 (Tinwald). It

has already sold sections in eight previous stages, and will continue to contribute traffic

demand to the SH1 intersections from the east. The views of this significant

development group is useful in providing insights and values of developers of the land

flagged for re-zoning and development both east and west of Tinwald.

Tinwald Primary School: Tinwald Primary School has pupils that travel to school from

both sides of SH1. The safety of this travel and the opportunities for active travel modes

for the school travel are key aspects of the school’s interest in the issue, as well as

potentially providing a very useful mechanism to gain an understanding the nature and

scale of the problem and the potential benefits of investment in the area from the

perspective of their school community.

Cycle club: both sides of the State Highway currently has cycleway lanes marked. Any

changes need to be made in consultation with this group and the workshops have

identified work packages that are suggested on both the state highway and local roads

that will improve user experience, overall use and safety of cyclists and pedestrians

Emergency Services (Fire Service, St John’s Ambulance and Police): These groups have

key interests and information regarding the corridor from the perspectives of ensuring

that they can maintain excellent response times to and from the Tinwald community,

and the safety/crash issues experienced at the SH1 intersections.

3 Strategic Assessment - Outlining the Need for

Investment

Inputs from the ILM workshops have allowed the problems and benefits to be identified and

compiled into the process.

Growing population and developments along this corridor, measured AADT and intersection

survey counts, plus modelling of the network have provided the evidence base for corridor

performance expected now (2016) and in the future (2026) for a range of intersection treatments

and scenarios.

Significant delays for side road traffic at State Highway intersections and a corresponding loss

of level of service are predicted in 2016 and worsening in 2026. The traffic model predicts a

variety of benefits (some notable and positive) for a range of different treatments depending on

the intersection. More importantly the model highlights where little benefit is gained.

3.1 Defining the Problem

A facilitated investment logic mapping workshop was held with key stakeholders in 2013.

The ILM process identified and agreed the following key problems. In brackets are the relative

weightings assigned to the problems in terms of the importance of addressing the problems.

Problem 1

An historical lack of inter-agency integrated road network planning

has led to impacts on development in Tinwald

Problem 2

Limited travel and transport options has led to poor customer

satisfaction

Problem 3

State Highway traffic is leading to increasing severance and access

issues in Tinwald.

The Investment Logic Map is attached as Appendix A

3.2 The Benefits of Investment

The potential benefits that could be realised through investing to address the identified

problems were identified in the benefits workshop held in 2013.

Benefit 1

Early awareness, understanding and support of projects

/programme by customers and stakeholders

Benefit 2

Effective staged investment programme for network and private

investment continuity

Benefit 3

An effective and efficient integrated transport system operates in

Tinwald

Benefit 4 Improved balance for accessibility and amenity of all users

Benefit 5 Improved Safety

The Benefit Map is attached as Appendix B. The Benefit Map has been completed with the

addition of potential investment KPI’s with associated measures and targets.

4 Strategic Context

4.1 Organisational Outcomes, Impacts and Objectives

The Tinwald Corridor Business Case, as a proposal, will be developed under the overarching

integrated planning approach to land transport investment guided by the GPS, Transport

Agency’s Statement of Intent, and the Investment Assessment Framework.

The corridor business case will respond to the organisational objectives in the following ways:

The Transport Agency has classified the state highway through the area as a national highway.

National highways have a set of performance metrics that are desirable, but that can be heavily

influenced through urban areas that they cross through. These are:

provide excellent journey times and journey time reliability

have no capacity constraints

assist more efficient freight supply chains, through efficiently and effectively catering for

significant freight traffic

form part of a safe, secure and resilient road network, including key routes to major

ports and airports

The Canterbury Regional Land Transport Strategy (CRLTS) does not explicitly mention any

projects nor key issues in Ashburton. Nevertheless the CRLTS expects a series of outcomes if

the Vision and Objectives are achieved, including

Improved land use and transport integration.

Reduction in fatal and serious injuries for all modes.

Improved health from increase in time spent and more people travelling by active means.

Improved journey time reliability on the strategic transport network and key freight

routes.

Connectedness is enhanced.

Ashburton District Council has adopted the Future Ashburton Development Plan as a blueprint

for the development of the district in the future. It contains information on and responses to

the impact of predicted district growth. The Plan includes proposed changes to existing zoning

in a number of areas to provide additional land for future residential, commercial and industrial

land needs. This includes medium and low density residential growth areas in Tinwald on both

sides of the state highway as well as investigating additional commercial areas adjacent to it.

The plan also proposes to review highway access points, due to the urban growth in Tinwald

and the ongoing traffic growth along the state highway. Implementing the plan for the future

development of the district is seen as a long term project for the Council and work will need to

be prioritised and staged over many years.

Ashburton District Council has adopted an Ashburton Transportation Study (joint study with the

Transport Agency) that provides a strategy and programme of measures to optimise the

Ashburton transport system.

The study presents a series of principles upon which the programme of measures was based,

some of which are relevant to this Strategic Case:

Principle 1: provide an integrated approach to land use and transportation planning so

as to minimise the adverse effects of one on the other;

Principle 2: provide safe and efficient access to SH1 at Tinwald

Principle 3: Encourage and enable safe use of alternative modes such as walking and

cycling.

Principle 6: Reduce side friction and conflict between through and local vehicles on

State highway arterials.

This study received strong views from the local community regarding access to the state

highway, and travel between Tinwald and Ashburton for local residents and businesses. The

Council has received these views, and accept them as a significant issue to address.

4.2 Alignment to Existing Strategies/Organisational Goals

The Strategic Case report demonstrated how the Tinwald Corridor Study project aligns with

strategic objectives and direction of the GPS, National State Highway Strategy, Safer Journeys

Action Plan 2013-15, Transport Agency Statement of Intent 2012-15, and SHAMP 2012-15 as

well as regional and local strategies and plans, such as the Ashburton District Development Plan,

the Ashburton District Plan, the Canterbury Regional Land Transport Strategy, and the

Ashburton Transportation Study. Refer to that report for the full reference table of information.

4.3 Context with comparative networks and issues

The State Highway traffic volumes in excess of 22,000 AADT near the existing Ashburton River

bridge are of a comparable volume to SH6 and SH6a at Frankton. Similar difficulties are also

experienced there with the inability to right turn and delay problems at side roads and property

accesses in general.

5 Changes/Updates to the Strategic Case

Some nearby changes outside the study area were noted during 2014 that have been modelled

in the 2014 PBC traffic model analysis so that early indications of any effects and the sensitivity

of them could be understood. These include a new supermarket and signals at SH1/South Street

to the immediate north of the study area and the Ashburton River 2nd

Urban bridge designation

that would have effects on the local road and State Highway traffic.

5.1 New Supermarket at South Street

During 2014 and the formulation of this PBC, a resource consent application was received by

Council for a major supermarket development immediately to the north of the current Ashburton

river bridge. Associated with this application is the proposal of the developer to construct

signals at the SH1/South street intersection as a condition of the application. Given the

likelihood of this application being favourably assessed the project team has modelled signals

at this intersection for the 2026 model during this PBC analysis.

5.2 New bridge designation

In 2014 the approval and granting of a designation for the 2nd

Ashburton bridge was gained.

The earliest possible opening of this is 2026 and hence the project team has modelled this

bridge taking effect from the 2026 model as part of the sub options for 2026.

5.3 Existing Strategic Assessment

The existing strategic assessment is confirmed from the previous as M/M/-.

PART B – DEVELOPING THE PROGRAMME

6 Programme Context

Tinwald is separated from the Ashburton town centre by the Ashburton River, and has significant

transportation issues due to it straddling State Highway 1 and the adjacent main trunk railway

line. Schools in the area and immediately adjacent to the study area along with a retirement

home are considerations. It is classified as a low socio-economic area of Ashburton, containing

5580 residents. While the area of study is urban the traffic generated is heavily influenced by

rural activities, rural development and rural vehicles. In addition due to the lack of public

transport and distances involved in this rural based community, significant reliance is placed on

private vehicles for travel needs.

6.1 Geographical & Environmental Context

Tinwald is the name of the area of Ashburton south of the Ashburton River, home to

approximately 5580 residents1

(estimate on 2013 data from census).

Tinwald straddles State Highway 1 for about 2.7km from the bridge to the South end with the

Main Trunk Railway Line adjacent to it. The railway line and State Highway cause significant

severance between East and West Tinwald.

A 330m two-lane bridge connects Tinwald to the rest of Ashburton. This bridge is approaching

capacity2

and investigations into building a second bridge are currently progressing with the

designation granted in 2014 but construction no scheduled until circa 2026.

6.2 Social and Community Context

Tinwald residents have a lower average income than the rest of Canterbury, and have a high

proportion of older people, with 17% over 65, compared to 14% in the Canterbury region (2006

data).

The Ashburton District is one of the fastest growing districts in New Zealand, behind only

Selwyn, Queenstown-Lakes, and Waimakariri from the latest census data (2013).

Lake Hood

The Lake Hood development at the South Eastern side to Tinwald, arrived at from the state

highway via Graham St, has been an area of significant rural residential growth with the new

District Plan (chapter 7) 3

allowing a further 350 residential lots to take the total to 500. This

new District Plan became operative in August 2014.

Pedestrian and cycle specifics

The 2.7km long urban area contains only one pedestrian crossing across the highway, no

signalised intersections, and four public railway crossing locations.

The movement of mobility scooters around the northern section of this study area and the

retirement home located on Carters Terrace is a particular point to note.

In addition the Tinwald area has school children who attend various primary schools and

Ashburton intermediate and Ashburton College on the North side of the bridge. While this is

outside this study area the movement of these pupils as pedestrians and cyclists is part of this

project and is a particular focus area around the Northern intersections (e.g. SH1/Carters), the

bridge crossing and how the local roads and cycle lanes function to cater for this group.

The movement of pedestrian traffic, especially children walking and on scooters, in the school

week, and in weekends, along the state highway and how they feed to it via and along the local

1 The ADC community planning document estimated 18% of the total Ashburton Population in Tinwald 2 (2013 AADT of 22,327 vehicles per day) 3 Chapter 7: ADC District Plan

streets needs to be well understood for any solutions to be optimised. The investigation of

where pedestrian crossings are best located is part of the integrated solutions required.

6.3 Economic Context

Ashburton is surrounded by productive farmland which has traditionally formed the basis of its

economy. In 2011 agriculture, forestry and fishing made up 26% of the local economy. This was

supplemented by manufacturing (18%), retail (12%), and business and property services (10%).

The Ashburton economy is growing quicker than the national economy, principally due to the

success of the dairy industry. In 2011 the GDP grew 2.1% (national growth of 1.6%) and in the

decade from 2001 to 2011 it averaged 2.8% p.a. growth (2.3% p.a. nationally).

7 Demonstrating the Need for Investment

Investment is needed in the short term to enable solutions that will address delays at all

intersections and severance. Any option and programme should be developed to address longer

term objectives and other developments, and integrated with safety outcomes for all users

7.1 Problems and Opportunities

The key problem identified, which is already occurring on the network, is delays at intersections.

This is at most intersections at both morning and afternoon peaks. The 2016 model predicts all

intersections having low levels of service (LOS) for side road traffic and by 2026 the delays are

significant.

The timeline for changing any significant land use driven solution is very long making it an

impractical short term solution and similarly the do nothing/ do minimum is not acceptable due

to the increases in side road delay and growing severance from high state highway traffic flows.

The second bridge option is the likely long term solution that largely resolves a proportion of

traffic volume for entry onto the state highway – but not entirely resolving delays by the time

that option happens. A second bridge will cause a significant amount of re-routing of traffic

given the different opportunities then available.

Therefore solutions that are both practical and achievable in the short term (pre-2nd

Ashburton

River urban bridge) without compromising mid/long term objectives and outcomes on the

network are the most desirable.

The second key problem is the severance of the community both sides of the highway makes it

difficult for cyclists, pedestrians and elderly (mobility scooters) to travel to schools and shops

so an integrated solution is required that takes into account these specific user groups at the

same time as any intersection improvements.

The opportunity exists now to implement improvements in a staged manner that integrate the

state highway with the local roads that will also cater for future developments such as increasing

Lake Hood development and a second Ashburton River 2nd

urban bridge long term.

7.2 Issues and Constraints

‘Issues’ or uncertainties include when a second urban Ashburton River bridge would be

constructed but modelling of this has given direction as to which suggested improvements are

aligned with this or not.

The growth of Lake Hood has been sufficient to clearly indicate that this is developing into a

major residential hub and the question only remains how soon, not if, it becomes bigger.

Any new major land-use development in the Tinwald area would most likely affect the network

efficiency negatively due to the current capacity issues.

A constraint on the layout of some options is the proximity of the railway line to the West side

of the state highway. This is particularly evident around Lagmhor Street where the lack of room

for any major improvement option to be realistically considered is a major constraint with the

railway to the West and significant operating businesses to the East.4

Some consideration is required with respect to the green space on the immediate West of the

highway. While it appears on first sight to be an attractive solution to use more of that for

highway widening (e.g. for through lanes on seagull and merge lane options or relocating the

cycleway off the state highway), this area does contain green space and trees that would be lost.

Tinwald is also a relatively low lying area and stormwater retention and flows paths around this

4 Page 10; Transport Agency 2009: SH1 Agnes St/Lagmhor Road intersection upgrade – Tinwald PFR report

area are critical. Council does not want to lose too much of this area so as to retain future

stormwater retention basin options.

Another constraint is funding. All projects are required to be economically justified and major

works are not likely to achieve that threshold in Tinwald compared to other areas of New Zealand

when competing for the funds from the NLTP.

7.3 Delay

The following tables have been derived from the 2014 analysis of the updated traffic model and

show the Do Minimum Level of Service for intersections through Tinwald for 2016 and 2026

modelled years and the morning peak, business hours and evening peak periods. Additional

information regarding actual numbers of vehicles turning at many State Highway intersections

is provided in Appendix G. This is important context information showing the actual number

of vehicles affected and in several locations poor levels of service occur where there are only a

small number of vehicles. Notwithstanding the poor levels of service also appears to have

resulted in some drivers finding alternative and longer routes of less delay.

It is important to note that the delays at State Highway intersections are mainly for vehicles on

the local road network when accessing the state highway at the key intersections.

The overall level of service across all time periods has deteriorated to LOS F as modelled to

2026. When the Ashburton River 2nd

urban bridge crossing is constructed the level of service in

the am and pm peak periods are still LOS F at two of the four key intersections.

The do minimum for each intersection is noted in the following tables and range from B-F in

2016 with deterioration from there to be mostly F in 2026.

The acceptable or target level of service for the key intersections is LOS C5

Considering the target of LoS C or better, it can be seen in the following tables that although

there are some issues in the 2016 results, the need to intervene grows significantly by 2026.

Table 1: Level of service (LOS) band widths

5 Canterbury Regional Land Transport Strategy

The 2016 Do Minimum models the existing strategic roads throughout Ashburton. The 2026

model is identical with the Do minimum of the signalised intersection at SH1/South Street.

For simplicity only the four main intersections (by volume) are shown here, the other 3 modelled

(Johnstone St, Hassel Street and Maronan Road) can be viewed in full in the Opus Options

assessment report. In general they follow similar trends to that shown for the main intersections.

Intersection

2016 SH1/Graham SH1/Lagmhor SH1/Wilkin SH1/Carters

AM IP PM AM IP PM AM IP PM AM IP PM

Do Minimum C B C C B C E C F E C F

Intersection



Do Minimum F D F F D F F F F F F F

Intersection

2026 Model SH1/Graham SH1/Lagmhor SH1/Wilkin SH1/Carters

OPTION 3: 2nd

river

bridge with:

AM IP PM AM IP P

M

AM IP PM AM IP PM

Do min (existing

network)

C A C D B D F D F F C F

Table 2: Model and level of service change for Do Minimum

8 Stakeholders

A targeted consultation process has been undertaken with a wide group of diverse key

stakeholders invited to participate in the workshops held through the Programme Business Case

phase. Good feedback was received from all involved who stated the collaborative process

enabled them to fully understand the issues and the process.

A wider group of less directly affected stakeholders has also been identified and they have had

an opportunity to provide input prior to completion of this PBC.

Media interest has been positive with all local outlets picking up the project media releases and

publishing information.

8.1 Consultation and Communication Approach

The process for identifying key stakeholders involved the Transport Agency and ADC project

staff in fortnightly conference calls and specific project meetings narrowing down whom in the

community could best represent a broad cross section of users that would provide a variety of

knowledgeable viewpoints. The workshops were attended by the following representing their

interest group as noted:

Stakeholder attendee as participant Representing

Cr Darryl Nelson ADC Councillor

Cr Stuart Wilson ADC Councillor

Cr Alasdair Urquhart ADC Councillor

David Harford (Urbis Ashburton Ltd) Developers

Gary Clement Tinwald Business representative

Peter Livingstone Principal Tinwald School

Hillary Boyce Ashburton Principal Assn

Diane Rawlinson Ashburton Citizens Assn

Jim Crouchley NZ Road Transport Assn regional representative

Rob Hooper Chair Tinwald Cycle Club (& Police)

Mary McConnell (ADC) Planner

Andrew Guthrie (ADC) Assets Manager

Brian Fauth (ADC) Contracts Manager

Colin Knaggs (Transport Agency) State Highway Manager

The following project team and support staff attended:

Project team member Representing

Neil McCann (ADC) Group Manager

Crissie Drummond (ADC) Support Officer

Matt Barnes (Transport Agency) Transport Agency Facilitator

Ian McCabe (Transport Agency) Planning & Investment Manager - Southern

Stuart Woods (Transport Agency) Acting Transport Planning Manager

Callum Wood (Transport Agency) Project Manager

8.2 Interested Parties

The following are other groups identified as potentially affected parties at a less directly affected level

and they have received information from the workshops as part of the overall consultation. i.e. not

directly involved in the workshops but given the information all received and the opportunity to comment

on it. These are:

Federated Farmers

AA

NZ Heavy Haulage Assn (Jonathan Bhana-Thomson, Chief Executive, Wellington)

Emergency Services (NZ Fire Service, St John, NZ Police)6

.

Agricultural contractors

Grey Power and Terrace View Retirement Village on Carters Terrace

School bus coordinator (Mid Canterbury Bus Services)

Lake Hood representative/developers

Café Time (local Tinwald business)

Child’s Play Pre-school (local Tinwald business)

Lushingtons (local Tinwald business)

8.3 Professional Engagement Process

The main component of the professional engagement process focused on first identifying

programmes and then option development within those programmes at the two workshops held

through this Business Case. Associated with this was pre-circulated material and stakeholder

review of subsequent notes and reports. Limited one on one engagement occurred as required

for some stakeholders.

This was facilitated by the following Transport Agency staff: Matt Barnes, as facilitator; Stuart

Woods (background and context), Callum Wood (summaries of traffic model analysis), and Neil

McCann of ADC, (local context).

8.4 Consultation Feedback

Business representatives (and the entire stakeholder group) are in agreement that while there

are businesses along this corridor, there will not be any major effects on them as already they

are largely impacted by either the inability to turn right from side streets (due to no gaps in the

traffic) or restricted by parking restrictions, (eg intersection of Wilkin Street outside the bakery

where parking is provided to the rear of the business).

Discussions on parking included the current availability of parking on the North bound side of

state highway 1 for parents to use for drop off and pick up of children from the pre-school on

the opposite side of the state highway. The stakeholder group thought that restricting these

parks or losing them to enable highway widening would improve safety.

Peter Livingstone spoke to the group regarding his views on how the school children arrive at

the highway from residential areas on both sides and in particular how the north end for crossing

over the bridge is not catering for them (safety and severance topics). He also observed that

students using scooters are not well catered for on the local roads or crossing the state highway

and that weekends are also high peak times for children travelling from residential areas (both

sides) to the shops along the corridor.

6 note Rob Hooper attended the workshops as the cycle club rep and is also a member of the local Police

Increasing use of mobility scooters in the Carters Terrace area, the inability for two scooters to

pass on the bridge cycle lanes and general lack of cycleway definition (used by scooters as well)

in the Northern end of Tinwald was discussed.

The working group were unanimous in agreement that the existing pedestrian crossing between

Lagmhor and Graham should be investigated to be moved South to the Graham /Jane Street

block due to safety concerns of vehicles exiting Graham and the quantity of over-dimension and

large vehicles turning at this intersection (right onto SH1) directly in front of the pedestrian

crossing.

8.5 Next steps

Where adjoining, the directly affected businesses will need to be closely involved in any

subsequent design process due to the effects from specific intersections improvements on the

highway or roads adjacent to them. Residences will have slightly different needs on some

aspects.

Similarly heavy transport, the retirement home and school user groups will have specific views

and needs on any detailed designs.

8.6 Media

As part of the PBC phase media statements have been released that have communicated the

broad process being developed by the project partners. A small number of local newspaper

articles have been printed on the project, mainly from the project team media release but also

other general commentary, and all in a neutral tone. In addition project information has been

provided on the ADC website. This approach will be continued, and may be expanded upon

when any general public consultation occurs in later phases.

9 Alternative and Option Assessment

9.1 Background

Previous studies of this corridor investigated and suggested traffic signals at Agnes/Lagmhor

without adequately defining the issues and full range of strategic responses and timing due to

the previous scope. This Business Case process is addressing that via the more structured and

holistic approach of the business case.

9.2 Initial assessment of Alternatives

The first PBC workshop (September 2014) discussed a number of themed programmes

(numbered from 1-7), that are best described as follows to address the issues identified to date:

Programme 1: Do minimum – basic maintenance, manage parking, markings, signs and

accessways

Programme 2: Safety approach which might include for example some central medians (wire

rope), parking management, cycle separation (in berms), separate lanes, speed reduction,

lighting etc

Programme 3: provision of alternatives to private vehicle which might include; TDM, cycle

paths/ lanes, pedestrian refuges, shuttle bus to CBD/school

Programme 4: State Highway severance reduction: signals, over-bridges, narrowing via

threshold type treatments, speed reductions (school zone or temporary)

Programme 5: Local road alternatives: local travel more on local roads and fewer State Highway

intersections, kerbing, LI /LO (Left in/Left out), review priority intersection controls

Programme 6: land use developments: controls on State Highway accesses, manage timing of

urban growth areas, Lake Hood

Programme 7: Do max; combination of all above including 4 laning of the existing state highway

and the construction of a second bridge

All of these programmes were discussed in detail and assessed in terms of their ability to achieve

the ILM problem statements and benefits and also achieving outcomes on realistic terms

(timeliness and cost).

These are summarised in the table included at the end of this section.

9.3 Option discussion

Within each of the programmes identified there are a range of options that could be

implemented that could deliver on the outcomes. How these options can be packaged together

to complement each other, or how they need to be packaged due to particular network needs

and/or dependencies to provide the best outcome for the entire network is important to

understand.

Options not taken forward:

First of all some discussion is required on options discarded from this point and why.

Programme 1 (Do min): was rejected as it doesn’t address the problem statements nor meet

any benefit outcomes. It is also a reputational risk to all agencies and given the District growth

is strong and anticipated to continue, this approach is not acceptable.

Programme 3 (Provision of alternates to private vehicles): Tinwald is affected by a large

component of rural based traffic where it is simply not feasible that alternates (eg public

transport) can provide for the needs. In addition a sensitivity analysis was carried out on the

existing traffic model to determine if a nominal 10% reduction in school trips was achieved

would this make a significant difference to traffic delays and other issues. The analysis showed

insignificant effects.

This does not mean a school plan is not desirable – it should be actioned, but the impact on the

overall network performance will be very small. Other parts such as independent cycle facilities

are integrated in all other solutions/programmes anyway so overall this programme is

discontinued.

Programme 6 (Land Use developments): It is recognised that the time to make change from

controlling land use change would take significant years to have effect. In addition any RMA

application could permit a large development inconsistent with the District Plan anyway so this

programme is discarded as unrealistic and not able to provide short term response to a present

issue or meet the PBC target outcomes.

Programme 7 (Do max – new bridge, 4 lane highway): While this achieves many benefits

implementation this option is expensive and is considered a long-term option in responding

issues post 2026. For an investment with a 40 year return period this option would need to be

investigated fully at a later date.

Options to take forward in a complementary role:

Travel planning and school travel plans. While limited in its ability to result in major impact

on the wider Tinwald network, these do have an important role to play in optimising

investment and can also flush out other previously unforeseen issues, or suggestions to the

overall main programme. There are also benefits to students and their families.

9.4 Assessment of options on Intersection Delay

To test the options for delay at key intersections a number of scenarios were modelled. The

following results are summarised below.

At SH1/Graham all options except signals are improvements with a roundabout being clearly

the best. Signals at Graham are a major dis-benefit for the 2016 model. At Wilkin all options are

improvements over the do-minimum, even the signals at Graham. Again the roundabout at

Graham offers the best option to LOS at Wilkin but only marginally over other options. At Carters,

none of the options offers any significant betterment over the do-min.

Not included in this report but noted for comparison, the previous 2009 PFR report7

on

intersection upgrades at SH1/Lagmhor Street concluded a level of service drop initially for this

intersection treatment option with signals, much as above for signals at Graham St.

The 2026 model analysis shows a clearer differentiation with the roundabout at Graham clearly

improving delay at Graham with other minor improvements in level of service at Wilkin and

Lagmhor. Signals at Graham do produce improvements but less than the roundabout and other

intersections do not benefit.

Modelling

The following tables have been derived from the 2014 analysis of the updated traffic model and

show the Level of Service for intersections through Tinwald for 2016 and 2026 modelled years

and the morning peak, business hours and evening peak periods.

The different options indicated are aligned with the programmes that were discussed at the

stakeholder workshops held in 2014 and largely represent safety, State Highway severance and

local road options. Refer to Table 1 in Section 7 for level of Service band widths.

As discussed in that section for simplicity only the four main intersections (by volume) are shown

here, the other 3 modelled (Johnstone Street, Hassel Street and Maronan Road) can be viewed in

full in the Opus Options assessment report. In general they follow similar trends to that shown

for the main intersections.

Intersection



Do Minimum C B C C B C E C F E C F

Option 1: left slip lane &

RT merge at Wilkin

C B C C B C B A C D C F

Option 1a: Signals at

Graham

D D D C C D B A C D C F

Option 1b: Signalised

ped crossing between

Agnes and Graham

B A B C B C B A B D C F

Option 1c: Signalised


Graham and Jane

B A B C B C B A C D C F

Option 1d: Roundabout

at Graham

A A A C B C B A B D C F

Table 3: 2016 Model and level of service changes for options at main SH1/Tinwald intersections

7 Opus for the Transport Agency

Intersection



Do Minimum F D F F D F F F F F F F

Option 1: left slip lane &

RT merge at Wilkin

F C F F C F F C F F F F


Graham

C D C F D F F C F F E F



Agnes and Graham




Graham and Jane


Option 1d: Roundabout

at Graham

A A A F C E F C E F F F

Table 4: 2026 Model and level of service changes for options at main SH1/Tinwald intersections

Intersection

SH1/Graham SH1/Lagmhor SH1/Wilkin SH1/Carters

OPTION 3: 2nd

river

bridge with:

AM IP PM AM IP P

M

AM IP PM AM IP PM

Do min C A C D B D F D F F C F


Graham

D D D D B D F D F F D F



Agnes and Graham

B A B C B C F D F F D F



Graham and Jane

B A B D B D F D F F D F

Option 3d8

: left slip lane

Lagmhor & RT merge at

Wilkin and change

priority of local roads

parallel to SH1

C B C D C D C B C F D F

Table 5: 2026 Model and level of service changes for option 3 at main SH1/Tinwald intersections

8 Combination of options 1 and 3

9.5 Discussion on second bridge (2026) key results

After a second bridge, signals at Graham are a major dis-benefit. All other options provide

benefits showing that they do so regardless of the second bridge. The left slip lane at Lagmhor

Street and right turn at Wilkin Street provide the best benefit to delay.

9.6 Discussion

In Tinwald, comparatively small numbers of turning vehicles (when compared with the numbers

of through vehicles on SH1) are likely to experience increasing delays. As a result of long delays

to right turners, drivers often turn left from the side roads on the East side and then U-turn into

West-side streets to re-enter the State Highway from the west side. The model also predicts this

and other re-routing affects.

The second bridge option returns actual delay data for the do minimum on all main intersections

turning right onto SH1 in the order of 1100 seconds (18 minutes). The 2026 Option 3d reduces

this significantly for all right turns to give results between 20-60 seconds for various

intersections.

9.7 Constraints and Dependencies

A supermarket proposal in the vicinity of SH1/South Street, currently subject to a resource

consent application at the time of writing this PBC, has as part of its application a proposal for

the developer to install traffic signals at that intersection. The effect of these proposed signals

on Tinwald is not immediately clear but initial evidence suggests that the distance from the

South Street intersection to the beginning of Tinwald (i.e. the Carters Terrace area) is sufficiently

large to result in the signals having a negligible effect. Certainly the effect further south would

be lower.

The signals at South Street may advance in the 2015-16 year but have been modelled only in

the 2026 programme as part of the do minimum option. There is likely to be only some minor

re-allocation of how trips are generated from the development and more impact likely on the

immediate area of the north approach to the SH1 Bridge.

The second Ashburton River urban bridge designation has been granted in 2014. From Council

feedback it is unlikely that this will be open until 2026 at earliest, therefore the modelling of

alternatives and options (refer Option 3 of 2026) reflects this by testing with and without the

bridge in the 2026 networks.

9.8 Key stakeholder feedback on alternatives and options

Timings

The key stakeholder group was in general agreement that the main intersections at Grahams

and Lagmhor are the main perceived problem in the community and that these are required to

be addressed as a priority in terms of timings. Less well understood by the group initially were

the interactions of the other intersections and how and why they currently operate as they do

with motorists self-regulating by trying different access points onto the State Highway from the

East where they aren’t congested or delayed less.

Following the presentation of background and traffic analysis information the group rapidly

understood the reasoning behind the discarding of the programmes described above and the

focusing of developing solutions and options around the remaining.

Stakeholder views outlined in section 8 were also informed by and fed into the discussions

related to programme assessment and evaluation.

10 Programme Options Development and Assessment

The programme option development process used a series of workshops to first brainstorm

programme alternatives and subsequently considering how different programmes stack up

against the desired benefits and outcomes previously noted. A review was held to analyse the

alternative programmes against a background of benefit, dis-benefits, risk, likely cost and

timeliness.

10.1 Programme Development

From the previous section the following programmes remained and were taken forward for more

detailed evaluation:

Programme 2: Safety approach which might include central medians, (wire rope), parking

management, cycle separation (in berms), separate lanes, speed reduction, lighting etc

Programme 4: State Highway severance reduction: signals, over-bridges, narrowing via

threshold type treatments, speed reductions (school zone or temporary)

Programme 5: Local road alternatives: increased local road travel/ reduced State Highway local

travel through fewer State Highway intersections, kerbing, LI /LO (Left in/Left out), better local

road routes

As these programmes individually did not address effectively all the issues or problems, it was

recognised that a preferred programme would involve blending elements from different

programmes.

10.2 Process

In August 2014, Opus updated the Ashburton Transport model, which was then 8 years old and

reported the updating process in the report “Tinwald Deficiency Assessment”.

This report included the data collected for the update, and following the re-validation, reported

an initial deficiency analysis of the existing network under 2016 and 2026 traffic demands. This

allowed key information to be presented to the first PBC workshop for context and improved

decision making.

Seven key intersections along the corridor were videoed to provide turning traffic data for the

model update and also to provide a means for counting pedestrians and cyclists.

The seven intersections surveyed are shown in the following figure and listed here as:

SH1/Maronan Road

SH1/Hassal Street

SH1/Graham Street

SH1/Agnes Street /Lagmhor Road

SH1/ Manchester Street

SH1/Wilkin Street

SH1/Melcombe Street /Carters Terrace

Figure 2: Location of 2014 intersection surveys

This process and data analysis then enabled the following high level conclusions to be made:

1 Agnes Street: not used for entering SH. Low numbers in from SH1 north only

2 Manchester St: Largely as for Agnes

3 Wilkin Street is close to total volume on Graham St

4 Graham Street is greater volume than Carters Tce

5 Carters seems to be avoided due to proximity of Melcombe with turning priority laws

giving Melcombe priority, and therefore Wilkin preferred at that northern end

6 Melcombe (West side) is greater volume than Lagmhor and about equal with Maronan

7 Maronan (at south end) is comparable volume to Melcombe and majority of traffic is to

and from North

8 Lagmhor Road is low percent high commercial vehicles (%HCV) compared to higher on

Graham Street (construction traffic at Lake Hood will be currently influencing this)

9 Graham Street: Right turn avoidance by 2026 and intersection would benefit being

controlled

10 LOS: by 2016 Wilkin Street becomes worst (very low LOS) and others near ; Carters

Terrace and Manchester Street are long delays

11 LOS: by 2026 all Tinwald intersections well into LOS F

Table 6: Summary of results of Deficiency Assessment Report

From this high level analysis a series of indicative treatments at various intersections were

developed to take forward. These were also aligned with the first workshop programmes ( i.e.

those numbered 2,4 and 5). Opus then carried out further modelling to give indicative responses

to a range of typical options being discussed in alternative programmes, and produced a report

immediately prior to the 2nd

PBC workshop titled “SH1 Draft Programme Options Assessment”.

N

Example treatments are summarised as follows and typical generic examples are shown in this

section of a seagull and slip lane type treatments. Note that not all treatments can be

implemented together and are presented as examples related to the programme theme:

ID Programme 2: Safety ID Programme 4:

Reduce SH1

severance

ID Programme 5: Local road

alternatives

1 Graham & SH1:

Seagull treatment

with merge lanes

1 Narrow various

sections via

threshold type

treatments and

speed restrictions

1 Lagmhor: Left in and left out

merge lanes

2 Relocate Ped crossing

to Graham - Jane

block

2 as above and add full seagull

treatment for Lagmhor right

turn plus Agnes restrict to

left in and out only.

3 Wilkin Street & SH1:

Seagull type

treatment with merge

lanes

3 Lagmhor: as above but

Agnes remains open as is

4 Roundabout

Graham/SH1

4 Manchester: Left in / out

only

5 signals at Graham/

SH1

5 Johnstone: Left in / out only

6 Carters: Left in / Left out

only

7 Carters: Left in / Left out

only and full Seagull /merge

south treatment on SH1 for

Melcombe

8 Melcombe: No RT on to SH1,

Allow SH1 RT on to Carters

as is

9 Melcombe: No RT on to SH1,

No SH1 RT on to Carters

Table 7: Typical Treatments allocated to different programmes9

Discussion on possible treatments

A seagull type treatment allows traffic travelling through and past intersections to remain in a

through lane but also has the advantage of giving side road traffic a merge (acceleration lane)

to merge with them (view sketch example in the appendices).

Examples of this type of treatment can be seen at the Southern end of Temuka where

Southbound traffic from the old state highway (King Street) merges with SH1 South.

9 View Appendices for typical examples of these treatments

A threshold treatment is typically designed to give the impression of a narrowing of the through

lane of the state highway which tends to reduce speeds and also gives a clear signal to motorists

that there is a change in the corridor (e.g from a rural speed environment to urban).

Examples locally are the entrance to Rakaia Township on SH1.

Other intersection treatments reviewed as options but discarded are signals and a roundabout

at Lagmhor (discarded as unlikely to be able to provide adequate stacking distance with the

railway crossing too close to the highway. Land take and business proximity also meant this

would be difficult to achieve).10

The Carters Terrace intersection was considered for major improvements, but the height

restricting railway over bridge on Melcombe street side would make this unusable for tall

vehicles.

10.3 Typical treatment example sketches

Figure 3: Seagull example and explanation

Figure 4: Seagull example with left turn slip/merge lane out (eg at Lagmhor)

10 Reference 2009 PFR Opus report to the Transport Agency

10.4 Do-Minimum Option

The initial traffic modelling considered the likely base networks at two future years: 2016 and

2026. This was reported in the Opus “Draft Programme Options Assessment”, report.

The 2016 Do minimum network runs modelled the existing roads and highway as is. The 2026

model network is identical except for the signalised intersection at SH1/South Street included

on the basis that this is a current planning application that is most likely to proceed in that time

interval.

10.5 Programme Assessment

The table below highlights the key benefits and dis-benefits arising from the traffic modelling

analysis carried out and provides the evidence trail to understand the decision making process

to retain or reject the various parts of the programme recommended to be developed. Refer to

the Appendices for more in depth discussion on the assessment of the programmes developed.

Summary of Findings from Traffic Modelling of Indicative Programmes

1 Left turn acceleration lane at Lagmhor and right turn acceleration lane at Wilkin provide significant delay reductions for access on to SH1 and no impact on SH1 through traffic regardless of whether the Ashburton second river bridge is constructed. A change of priority at Wilkin/Grove to prioritise traffic from the South on Grove would provide benefit.

2 A roundabout at SH1/Graham would provide significant network wide benefits & reduced side road delay by 2026 (if no Ashburton river 2nd urban bridge), but does not improve pedestrian or cyclists safety issues. Some early small dis-benefits result from this sub-option.

3 Signals at SH1/Graham provide significant side road delay reductions by 2026 (if no Ashburton river 2nd urban bridge), but in 2016 all traffic re-routes to avoid them. Significant dis-benefit (delay) to the whole network due to traffic delays at signals. Does improve pedestrian and cyclists safety issues

4 Modal shift of school traffic does not provide significant reductions to delays overall

5 Signalised pedestrian crossings at either location proposed (of the two blocks between Jane and Lagmhor) do not provide significant reductions to side road delays but would provide safer crossings to pedestrians, cyclists, mobility scooters and children on scooters with corresponding dis-benefits to network performance.

6 Signals at South Street/SH1: The effect on the Tinwald network from any signals would be negligible due to the distance from this intersection over the North side of the bridge.

7 The 2nd bridge option removes a significant number of vehicles trying to access SH1 from local roads and does reduce SH1 volume as well, but by 2026 regardless of this reduction in volume there remain delays for all SH1 intersections side road traffic (albeit reduced from the do min/do nothing ie in the order of 15-60 seconds down from 1100 seconds)

8 The 2nd bridge creates significant economic benefits

9 Previous feasibility documents (for Agnes/Lagmhor signals) remain current with significant dis-benefit for signals at Lagmhor

10 Acceleration lanes, (Lagmhor and Wilkin) continue to provide benefit even if 2nd bridge option is carried out.

11 2016 model and specific comment on likely changes resulting from options: Option 1a( signals at Graham) ; Some traffic from Tinwald East would re-route to avoid signals and would require local road measures to constrain this, eg Agnes would become quicker due to signal operation at Graham providing gaps Option 1b and 1c: signalised crossings; both cause significant re-routing due to delays of crossings on the SH1 south of Lagmhor. West re-routes to Lagmhor and East via Grove. Option 1d: roundabout at Graham; causes significant re-routing to avoid roundabout in early years, again to Lagmhor and via Grove to avoid Graham

12 Delays from signalised pedestrian crossings is not sensitive to the two locations tested therefore any improvement works should be sited from pedestrian desire line surveys rather than network performance.

Table 8: Summary of findings from Draft Programme Options Assessment Report

10.6 Cyclist and pedestrian specific comments

This business case and the options considered in the modelling have not included any

assessment of improvements to the cycling and pedestrian facilities ‘along’ the route.

Intersections and crossings have been but there is a clear need to consider the entire route and

wider still with how the local roads (footpaths or shared routes) feed into the state highway

section, and also how Ashburton via the bridge is better connected for pedestrians and cyclists.

Results from the model indicate that a signalised crossing between Agnes and Graham and

between Jane and Graham would provide significant improvements for walking and cycling.

Discussions with the stakeholders confirmed this.

10.7 Qualitative Assessment to deliver the benefits listed within the ILM

A subjective, qualitative assessment and workshop feedback indicate that a mix of all 3

programmes of local road alternatives with a safety and severance reduction programme has

the ability to deliver a higher proportion of the benefits sought in the ILM than options that

focus on one theme only. In reality any local road alternate has inherent safety outcomes and

all solutions have the ability to integrate State Highway severance reduction measures.

Summary of Assessment of Programmes against Benefits Statement

Using the rating table (Table 9) to

subjectively score the programmes

against the desired benefits is a valid

way of assessing them. Table 10

concludes that all programmes have

merits and overall similar performance

but when a focus is made on the %

weighting, that Programme 5 is the

best.

Table 9: Legend for rating of

programmes

Programme

Benefits 2: Safety 4: Severance

Reduction

5: Local road

alternatives

Understanding and support of

Projects by customers and

stakeholders (5%)

Timeliness and ability to deliver

programme (25%)

Efficiency and integrated (30%)

Improve accessibility of all users

(20%)

Improve safety (20%)

Total subjective assessed

benefit

7 6 8

Table 10: Subjective assessment of programmes vs benefits

Symbol Rating Description

Major

Positive

Produces major benefit

Minor

Positive

Produces minor benefit

- Neutral Produces no or negligible

benefit

x Dis-

benefit

Dis-benefit

FF Fatal Flaw Dis-benefit of oRoader

that should be

discontinued

10.8 Discussion on the option results

In order to compare the example options as assessed in the modelling a multi-criteria analysis

has also been completed.

Options and sub-options were defined by first reviewing where the priority issues and problems

were and Option 1 (both merge lanes at Wilkin and Lagmhor) is easily identified as alleviating

access from west and East by low cost measures.

Option 2 (Tinwald school mode shift) was an attempt to understand if the model, and solutions,

were sensitive to the impact of a change that may be able to be achieved via a mode shift and if

it was practical and beneficial to target this area. Option 2 following these investigations was

discontinued as the model shows this had a negligible effect on the network.

Option 3 (the second river bridge) has been tested as a future solution (given confirmation of a

designation in 2014). This had to be modelled to understand any sensitivity related to this on

the network.

Each option has been assessed in terms of the following:

Main Options assessment

Option

Description

Side road

delay

impact

Ability to

reduce

network

travel

times

Improvement to

pedestrians/cyclists

1 Acceleration/merge

lanes

Significant

delay

reduction

for local

roads both

sides

Significant

reduction

for all

roads

both sides

Neutral -

2 Tinwald School

modal shift

Negligible - Negligible - Encouraged via better

facilities

-

3 Ashburton River 2nd

urban Bridge

(2026)

Transforms

network;

significant

delay

reductions

Significant

reductions

Minor desire lines impact

only

-

Table 11: Assessment of Main Options

Option 1 Sub-options assessment

Option

Description

Side road

delay

impact

Ability to reduce

network travel

times

Improvement to


1a Signals at

Graham

Halves

worst right

turn delay

in AM peak

(2026)

Signals cause SH1

traffic delay which

reduces benefits

x Introduces controlled

crossing across and

SH1

1b Signalised

crossing

(Agnes

/Graham)

Negligible - Signals cause SH1

traffic delay which

reduces benefits


crossing across SH1

1c Signalised

crossing

(Graham/Jane)


traffic delay which

reduces benefits


crossing across SH1

1d Roundabout at

Graham

Halves

worst right

turn delay

in AM peak

(2026)

Provide additional

network benefit

to merge lanes

No improvement -

Table 12: Assessment of Option 1 Sub-Options

Note for options 1a and 1d, a two tick rating would apply for delay if the second bridge didn’t

occur however this is reduced to one tick due to the predicted early years of disbenefit of these

options and the result of state highway traffic being delayed.

Option 3 Sub-options assessment

Option

Description

Side road

delay

impact

Ability to reduce

network travel

times

Improvement to


3a Signals at

Graham


traffic delay which

reduces benefits of

merge lanes


crossing across and

along SH1

3b Signalised

crossing north


traffic delay which

reduces benefits


crossing across SH1

3c Signalised

crossing north


traffic delay which

reduces benefits


crossing across SH1

3d Roundabout at

Graham

Minor Significant benefit

No improvement

/neutral

-

Table 13: Assessment of Option 3 Sub-Options

Discussion on Multi-Criteria Assessment and results

Results indicate that once a second bridge is constructed that the addition of signals or

signalised pedestrian crossing would have a negative impact on the network – however all merge

lanes continue to provide benefits.

Overall assessment, considering all impacts, benefits and dis-benefits across the network

indicates a roundabout at Grahams/SH1 is the most effective way to improve delays in the short-

medium term. This should be carried out in conjunction with merge lanes at Lagmhor (left) and

at Wilkin (right turn).

Signals are slightly less effective than the roundabout option.

Signalised pedestrian crossings do not provide any significant side road delay reductions but

would provide a safer crossing for pedestrians and cyclists. The model indicates location is not

sensitive for network performance for vehicles and if selected, they should be located to provide

best desire lines for these user groups. As noted, the working group gave a strong unified

message that the existing crossing between Lagmhor and Graham should be shifted South a

block due to safety concerns.

The key conclusions drawn from the above analysis are that while some areas of this network

aren’t performing well at peaks, most is operating acceptably. Nevertheless, it is notable that

within the next 10 years there is significant deterioration at all State Highway intersections along

the Tinwald corridor with problems and issues that developing. This therefore leads to a

conclusion that programme development should continue through the investigation phases, at

very least, so that any interventions can be introduced in a timely fashion.

11 Recommended Programme

The recommended programme includes a number of parts that are most effective to network

efficiency if completed together but some degree of phasing and timing would be possible

without compromise.

The main core works include channelisation improvements at a number of key intersections that

will assist immediately with delay issues.

Concurrently a plan for investigating the delivery of a roundabout at Grahams should be

commenced.

Other supporting works packages including cycleway reviews, intersection priority reviews,

speed limit reviews and pedestrians crossing locations are all recommended to enhance the

entire network safety and efficiency.

11.1 Programme Overview

All three programmes have similar strategic responses and relatively very close benefits. Due to

the nature and type of the proposed works all have a mixture of safety, severance and local road

alternate type components. Many could support walkways and cycleways. The key to developing

this programme is understanding what part is core work now and what would best be developed

later.

Core Activities

The preferred programme of works recommended for delivery at or before 2026 includes all of

the core activities described below.

Core activities include channelisation improvements such as merge lanes (left turn at Lagmhor

and right turn merge lanes at Wilkin), as in every case they are proven to be beneficial to the

network regardless to what happens later with a second bridge or other intersection

improvements. They have no negative effect and are low cost. No private land is required and

the intended solutions have no major impact on the existing network (for example parking at

intersections and beside existing businesses is already restricted). Therefore acceptance is likely

to be very high and consultation and liaison requirements reasonably straight forward.

Due to the minor nature of these works it is envisaged that minor improvement funding is the

likely funding mechanism.

As part of the core work and in parallel with the above, an indicative business case should be

developed now to investigate a roundabout at Grahams/SH1.

Given the likely timeline for moving through the early phases it is important that this is

commenced now so that eventual construction can be timed for optimal opening, which may be

in the 2015-18 NLTP period.

Supporting Activities

The remaining intersection improvements at Carters/Melcombe, Manchester, Johnstone and

Agnes all fit in with the above core works as they assist with the desired outcomes of restricting

movement on the network and provide more channelisation to assist the whole network. South

of Graham the other (currently minor traffic volume) intersections would also benefit from a

local road review that would check any improvement strategy or changes that could be

accommodated to enhance the entire network.

Optional

If funding and opportunity value allows, crossing points should be established in conjunction

with the above intersection improvements, and at both blocks (Graham/Jane and

Graham/Agnes) so that pedestrians and cyclists have further safe opportunity to cross the state

highway.

A cycle network plan should be developed that would consider and include the following key

points:

should the current cycleway be removed from the state highway on to dedicated new cycle

paths on the West side (in the existing green area), and on the East side incorporated into

a shared footpath?

A complete review of cycleway connectivity from the local roads, particularly on the West

side of the state highway and how this network feeds into the state highway and further

north around the current Ashburton River bridge.

A school travel plan should be completed.

A local roads’ intersection review should be undertaken of vehicle priorities focusing on how to

best support the other actions that come from this report and the likely programme of works

ahead.

A speed limit review carried out.

11.2 Programme Implementation Strategy and Trigger Points

The indicative programme11

implementation is composed of the following steps

Short term (2015-18 funding programme)

Conduct a single IBC for roundabout at Graham and short term works (Lagmhor Road

and Wilkin Street channelization) and other related supporting works

Develop plans for investigating the entire route (and feeder streets) for how cyclists and

pedestrians are best catered for

Medium term (2018-21 funding programme)

Construct cycleway improvements along and across state highway corridor

From short term investigations:

Other pedestrian crossings and thresholds

Other minor intersection improvements and modifications

Construct roundabout at Graham and other works required in local streets for any

priority changes

Speed limit review

Long term (2026 +)

When Ashburton river urban 2nd

bridge constructed; complete priority changes to local road

network

11

This is a first estimate of timing and funding and any programme is subject to funding criteria at the

time

Note Implementation responsibilities will be determined as projects are developed

12 Recommended Programme – Assessment

The preferred programme has been reviewed using the Transport Agency assessment

framework and given a funding profile of M/M/L

The programme has been derived from the issues and problem statements.

Project risks are assessed as low.

Low cost solutions have been tested for effectiveness and discontinued where low or nil

benefits found to exist.

This section assesses the performance of the recommended programme against three key

criteria:

Programme Outcomes

Programme Risks

Value for Money

12.1 Programme Outcomes

The programme has been specifically targeted and derived to meet all of the specific outcomes

from the issues and problem statements including:

provide an integrated approach to land use and transportation planning so as to

minimise the adverse effects of one on the other;

provide safe and efficient access to SH1 at Tinwald

Encourage and enable safe use of alternative modes such as walking and cycling.

Reduce side friction and conflict between through and local vehicles on State highway

arterials.

12.2 Programme Risk

This section considers the risks associated with the programme. These can be broken down

into the following key risk areas with a brief commentary on reasons for the subjective

assessment scores: Table 14: Indicative Programme

Risk Assessment Commentary

Technical

Low Recommendations detail standard solutions

widely used in NZ

Operational

Low Standard details that cater and allow for all

operational risks

Financial

Low Known costs are likely to be on low side and

funded. Some discussion on where funding split

lies may have some minor impact on ADC. Can be

staged.

Stakeholder/Public

Low Low as high expectation for something to happen.

Even where works most likely to occur the impact

on directly affected businesses is negligible to

none. Some risk of expectations of signals or

more substantial solutions.

Environmental and

Social Responsibility

Low Low impact as only minor green space required.

Already urbanised area and proposals are only

modest changes.

Safety

Low All solutions are targeted to improve safety

Economy

Low All solutions are targeted to improve efficiency

and provide value for money.

Table 15: Risk Assessment

12.3 Value for Money

Certainty of the ability to achieve value for money arrives from a variety of ways. First is that the

traffic model has steered us to where we are likely to get best value by indicating when we need

to do what intervention. The proposed programme is able to address identified problems and

achieve benefits, whilst proposing low cost interventions. We have also tested sensitivity of some

solutions and recommended no action where these didn’t indicate a positive result. While no

actual project cost estimating exercise has been developed this early in the process we know

from anecdotal evidence that the costing parts of the programme recommended are reasonably

well understood from other projects of similar scale and complexity.

12.4 Assessment Profile

The programme was assessed using the latest Transport Agency Investment Assessment

Framework profiles. An assessment profile of M/M/L has been determined for the programme

using the Transport Agency’s funding allocation process as detailed below:

Strategic fit of the problem, issue or opportunity that is being addressed: M

This is based on the criteria being satisfied of:

Easing of congestion in main urban areas

Effectiveness of the proposed solution: M

This is based on all criteria being satisfied, including being part of a Transport Agency supported

strategy (Ashburton Transport Study); is significantly effective (as proven by the revised traffic

modelling carried out); provides a long term solution with enduring benefits (also proven by

traffic model)

Benefit-Cost efficiency of the proposed solution: L

While no economic assessments have been formally carried out, from known project costs of

other similar type work packages, the benefits are known to be relatively good for modest

funding. Therefore a BCR between 1 and 2 is nominated as an interim measure until this can be

confirmed in subsequent phases.

13 Programme Financial Case

13.1 Indicative cost

No costing work has been completed at this stage. Options have only been considered in low,

medium or high cost likelihoods and scenarios. The proposed programme is likely to only be

either minor works or low cost block projects.

13.2 Funding arrangements

It is intended that these investments will be funded by a mixture of work categories and will be

split by organisation depending on the project. I.e. State Highway and local road contributions

in line with standard arrangements although ADC has indicated some funding for use on

Indicative Business Cases.

13.3 Affordability

The affordability of the overall programme is likely to be good given the relatively low cost of

implementing the works described in the core activities from indicative past projects of similar

nature. In addition no major land issues are foreseen and ground conditions are also relatively

good where any new construction is likely. Therefore project risks (and costs) are accordingly

rated low.

No major affordability issues are envisaged.

PART C – DELIVERING & MONITORING THE PROGRAMME

14 Management Case

14.1 Programme Governance and Reporting

Governance Structure

The project’s governance structure involves the senior key members of The Transport Agency

Christchurch office and ADC that provide strategic leadership and who perform an oversight

role to ensure that all and any improvement works are well planned and aligned with other

investments in the area. The senior staff from both organisations have roles and responsibilities

that include:

Strategic Leadership

Ensure a clear and concise vision is in place

Approve the outcomes of the PBC and subsequent business cases

Ensure that the delivery team develops the project in a way that coordinates and

integrates well with the strategic direction of each organisation

Oversight (monitoring, evaluation and reporting)

Provide a discussion forum between ADC and the Transport Agency to respond to

requests for decisions or recommendations received from the delivery team

Review the impact of the programme

Monitor the efficiency (and coordination) of resource in each organisation to achieve

the outcomes sought in the business case

Ensure accuracy and timeliness of reporting processes and systems are maintained at

a high level at all times

(No Project Control Group, PCG, is thought necessary for this project due to the particular

requirements of this project being not complex enough to warrant it).

Project manager

Each organisation shall appoint a project manager responsible for delivering the project. The

project manager from the Transport Agency leads and manages the team on a day to day basis.

The programme is to be submitted to the LTP/NLTP and delivered as a series of related but

separate projects.

14.2 Stakeholder Engagement and Communications Plan

The stakeholder engagement approach is to continue as is with the key group being fully

incorporated into the process via specific workshops throughout. The second tier of

stakeholders will also be given specific ability to feed their input in at key points. They will also

receive all information available. Individual projects will expand on this as detailed development

occurs, and include general public consultation per normal project development.

14.3 Programme Performance and Review

The benefit map is included in the Appendices and this covers how investment KPI’s can be

measured simply and effectively. In addition now that we have a baseline survey, and good traffic

data, all subsequent monitoring and videos of intersections etc, can be used to check and

validate improvements post construction.

Crash rates can be monitored for any emerging new trends or improvements. Anecdotal

evidence from emergency services, via interviews and submission to public processes (such as

LTP’s), will provide good feedback on how the corridor performance (and local roads) has

improved.

Page I

Appendix A - Investment Logic Map

Page III

Appendix B – Benefits Map

Page IV

Appendix C – Location Map

Page V

Appendix D – Background Evidence to Needs

Operating Environment

With the competing interests of long-distance travel, often of significant economic value, and

the transport demands of residential (and to a lesser extent commercial) growth in Tinwald,

there is the need to understand the key problems and issues on this corridor.

The strategic solution needs to be found that will best meet the expectations and objectives of

the strategic function of the State highway and the aspirations of, and developments aligned

with, the Ashburton Futures Strategy.

Growth in population and employment

The population of Ashburton District was estimated to be 30,100, as at 30 June 2011 and the

recent 2013 census data returns an actual of 31,000. Over the previous census period to 2006,

the population of Ashburton District increased 7.6%, making Ashburton District one of the

fastest growing rural districts in the country at the time12

. This is much higher growth than the

previous census period, (1996– 2001), when the district’s population grew by just 1.1%.

The district’s population has grown steadily over the past few years, driven primarily by local

economic growth. Ashburton District’s population looks set to continue this growth, reversing

earlier trends of low or no growth. The 2013 census data shows a further large 13 % increase

from 2006 to 2013.

The demographics of Ashburton District are changing, and they are expected to change further

in the future. Notable in the latest census data is the large increase in the 25-44 age range

synonymous with the likely increase in dairy activity and some general population shift from

Christchurch post-earthquakes. Population medium projections13 estimate that in 2016

Ashburton District’s population will have increased to 31,200, and a medium projection estimate

indicates a population at 2031 of 33,900 people (and a high projection estimate for 2031 of

37,000).

Within Ashburton, Tinwald as a sub-area represents about 18% of the Ashburton population14.

Tinwald also has a notable light industrial zone towards its southern end. The Future Ashburton

Development Plan recommended that some further residential (at usual suburban densities and

lower greenbelt densities) development is allowed to provide choice in living environment to the

east and west of the current Tinwald urban area. Some further investigation of the commercial

area is proposed to address the lack of focal meeting space for the area, the mix of activities,

its size and the strip nature of commercial development which is occurring there.

The growth in population (and employment in the Tinwald commercial and industrial areas) and

developing land use patterns will put increasing pressure on the transport network through the

area, particularly SH1 which forms the backbone to the road network and is the only nearby

route to cross the Ashburton River into Ashburton CBD area.

Traffic Movements through Tinwald

In 2013, the AADT on State highway 1 in Tinwald was 22,327, with 12.94% of the traffic stream

being trucks (higher than normal for urban arterials). State highway traffic volumes are

increasing at approximately 1.8% / year.

Independent surveys taken in 2012 show that State Highway traffic travelling straight through

Ashburton/Tinwald constitute about 12-14% depending upon time of day. Therefore the balance

of traffic on the state highway in Tinwald has at least one end of their journey located within the

Ashburton township.

12 Ashburton population facts and figures report, Sept 2011, ADC Community Planning Department 13

NZ Stats: Area unit population projections by Territorial Authority ( 2013 Data)

14

Source : ADC Community Planning Department

Page VI

The high State highway volumes and speed of trucks make pedestrian crossing of the State

Highway difficult, especially for school children.

Safety

Road user safety on SH1 through Tinwald is perceived as one of the key transport issues by the

local community. This is principally focussed on right turn movements from side roads onto

the State highway throughout Tinwald. The other safety issue relates to crossing the State

highway by pedestrians and cyclists.

Over the 5 years of crash records (2009-13) there have been 41 crashes between the Ashburton

River and the southern urban boundary with 18 at intersections. This section of state highway

is approximately 3 km long with 9 T-intersections and 2 cross-road intersections.

There has been one fatal crash, (of a van failing to give way to a pedestrian near Graham Street),

3 resulting in serious injuries and 10 resulting in minor injuries. The crashes are evenly spread

along all intersections. This recorded crash rate is lower than the typical crash rates as outlined

in the Economic Evaluation Manual.

Delay

Most key intersections along the Tinwald corridor experience increasing delays at peak periods

during the day. The level of service for vehicles turning right onto SH1 by 2016 is considered to

be moderately high with predictions that by 2026 it will increase significantly to be a very poor

level of service.

Status of the Evidence Base

Previous studies have occurred in 2008 (Ashburton Transport Study) and 2009 (PFR: SH1: Agnes

St/Lagmhor Road intersection Signalised Upgrade – Tinwald). These provide significant levels

of transport related data and information. Updated crash and traffic volume data has been

sourced from the Transport Agency systems to 2013.

Video analysis was carried out in mid-2014 of 7 SH1 intersections including pedestrian and

cyclist counts.

Whilst there are acknowledged growth proposals for east and west Tinwald, the actual level and

rate of development is unknown. Assumptions are incorporated within the transport model

(recently updated) as used in the analysis underpinning the Ashburton Transport Study

Geographical and Environmental Background Information

The population of Ashburton District increased 7.6% over the census period to 2006 and a

further 13% for the period 2006 to 2013 making this one of the fastest growing Districts in the

country at the time. The urban area covers approximately 230 hectares and is predominately

residential, although there are significant areas of industrial development at the southern end.

Facilities include a primary school (roll of 230), and other schools in Ashburton over the nearby

bridge who rely on the catchment of Tinwald (ie students travel through to Ashburton), a pre-

school, a retirement home, several churches, golf course, velodrome and sports centre, and a

museum.

Land is generally flat being situated on the Canterbury Plains, with the braided Ashburton river

bordering Tinwald to the northeast.

Page VII

Social and Community Background Information

Tinwald residents have a lower average income than the rest of Canterbury, with a median

income of $22,400 compared to the Canterbury regional median income of $23,500. A

comparatively high proportion of Tinwald’s workforce is employed as labourers, machinery

operators and drivers, and a comparatively low proportion are employed as managers and

professionals. 39% of Tinwald residents do not have school level (or higher) qualifications,

compared to 25% in the Canterbury region. Tinwald Primary School has been rated as Decile 6

by the Ministry of Education.

Tinwald has a high proportion of older people, with 17% over 65, compared to 14% in the

Canterbury region (2006 data). However there is a noticeable increase in the 25-55 age group

that is starting to change trends not yet picked up in all census trend graphs.

Page VIII

Appendix E – Background information to development of

options

Assessment of Option - Programme 2: Safety

Description: This programme option focuses on improving safety along the corridor by

reviewing key intersections and suggesting treatments that either reduce risk or are specific

safety improvement treatments, particularly for vehicles.

Programme 2/1: Seagull type (ie half seagull) treatment at SH1/Graham. This addresses

the traffic originating from the East trying to turn right on to SH1 by incorporating a north

bound merge lane and a left in slip lane from SH1.

How it delivers against the outcomes: This treatment would make the right turn

significantly easier therefore efficiency and safety improves for motorists. Dis-benefits are

that the state highway severance would be slightly increased with no improvement to

pedestrian or cyclist safety. Losing parking on the West side of the highway may occur in

this location and could be argued as improving safety (outcomes).

Risks: Should be combined with other intersections treatments otherwise risk of only

shifting the safety risk at this intersection to others not improved. Loss of parking will have

some minor impact on the freedom of locals and public perception. The removal of some

trees and loss of green space is likely which will result in possibly some adverse public

comment and Council will have some comment on the loss of land (as some potentially

required for stormwater retention in this area).

Programme 2/2: On demand signalised pedestrian crossing – in Graham /Jane block or

Agnes /Graham block. Signalised crossings would provide a gap in state highway traffic

that would provide gaps for all other side-road traffic close by and combined with a median

island refuge would provide a safer crossing point for pedestrians.

How it delivers against the outcomes: The model analysis shows that delays on

intersections are not improved significantly (in both 2016 and 2026) but they would provide

additional safety to pedestrians with some minor corresponding dis-benefits to the overall

network as State Highway traffic is delayed a minor amount and side road traffic re-routes

to avoid these points of delay.

Risks: Pedestrian crossings mid-block could be an out-of-context surprise to state highway

traffic without other mitigation such as signage, thresholds and education. Could give a

false sense of security to users.

Programme 2/3: Seagull type treatment (ie half seagull) at SH1/Wilkin St. This addresses

the traffic originating from the East trying to turn right on to SH1 by incorporating a north

bound merge lane and a left in slip lane from SH1.

How it delivers against the outcomes: Similar to programme 2/1 this treatment would

make the right turn significantly easier therefore efficiency and safety improves for

motorists. Dis-benefits are that the state highway severance would be increased with no

improvement to pedestrian or cyclist safety. Some land most likely required ie the green

space to the West, which has been noted by ADC as potentially required for stormwater

disposal. Some parking areas on the West side in the vicinity of the pre-school would be

lost, or the entire road corridor could be moved even further West (ie further into current

green space) to retain them if the safe operation of the parking is achievable. Losing parking

on the West side of the highway in this location could be argued as improving safety.

Would be best combined with restricting traffic at Carters (refer other programmes) as this

would then direct traffic where it is best managed.

Risks: Should be combined with other intersections treatments otherwise risk of only

shifting the problem. Loss of parking will have some minor impact on the freedom of locals

and public perception. The removal of some trees and loss of green space is likely which

will result in some Council and possibly public risk.

Page IX

Programme 2/4: Roundabout treatment at SH1/Graham St. This addresses the traffic

originating from the East trying to turn right on to SH1 by constructing a roundabout on

SH1.

How it delivers against the outcomes: This treatment would significantly reduce side road

delay in 2026 but in 2016 local traffic re-routes to avoid this intersection (less than signals

option below). Dis-benefits are that the state highway severance would be marginally

increased with no improvement to pedestrian or cyclist safety.

Would be best combined with other intersections (refer other programmes) as this would

then direct traffic where it is best managed.

Risks: Programme timing and funding are major risks

Programme 2/5: Signals treatment at SH1/Graham St. This addresses the traffic originating

from the East trying to turn right on to SH1 by constructing signals on SH1.

How it delivers against the outcomes: This treatment would significantly reduce side road

delay in 2026 but in 2016 local traffic re-routes to avoid this intersection (more than

roundabout option). Benefits are that the state highway severance would be decreased with

improvement to pedestrian and cyclist safety. Dis-benefits are that the state highway delays

would be increased and corresponding loss of service.

Would be best combined with other intersections (refer other programmes) as this would

then direct traffic where it is best managed.

Risks: Programme timing and finding are major risks

Assessment of Option - Programme 4: Reduce State Highway Severance

Description: This programme option focuses on reducing the State Highway severance through

narrowing (standard threshold treatments), speed reduction, installing refuges for pedestrians

or a combination of all these at locations to be determined. Other options of over-bridges and

underpasses were also discussed and while not discounted at this stage they are thought to be

not economically justifiable, not a safe environment (underpass) and difficult to install in a

confined corridor. Other options of controlled (i.e. signalised) crossings of SH1 are discussed

above.

Programme 4/1: threshold type treatment at locations to be determined. This addresses

the traffic arriving at the end of the corridor so that a changed speed environment is

recognised from rural to urban or placed periodically along to reinforce environment or

key points

How it delivers against the outcomes: This treatment would make the crossing of the

state highway significantly better by providing refuges in the median area and shorter

distances across lanes. As a consequence of this programme the speed environment would

be less therefore safety benefits are also achieved. Safety is further enhanced by integrating

into this type of treatment by the usage of low cost signs that either restricts speed e.g.

school zones or variable message signs with ‘slow down” message.

Risks: Efficiency of the state highway could be compromised but all design would be in

accordance with standard widths for over-dimension and swept path tracking into side

roads.

Programme 4/2: speed management

Part time or permanent changes to speed – either school times/routes or modify 70 kph zone

etc.

Assessment of Option - Programme 5: Local road alternatives

Description: This programme option focuses on improving efficiency along the State Highway

corridor by reviewing key intersections and suggesting treatments that either removes delays

Page X

or direct traffic to where it is best managed through other treatments. It also encourages local

traffic to use local roads more and reduce State Highway volumes and access delays. Therefore

some dependencies occur and some specific safety improvements result directly from the

efficiencies as well.

Programme 5/1: Lagmhor street/SH1left out merge lane with full seagull intersection

treatment. This addresses the traffic originating from the West trying to turn left on to

SH1 by constructing a dedicated left merge and acceleration lane and a right turn

merge/acceleration lane from Lagmhor acceleration lane Southbound. Agnes traffic sub

options within this.

How it delivers against the outcomes: This treatment would improve network efficiency.

The left turn from the West on to the state highway is significantly easier by providing a

means to accelerate and merge with traffic and not wait. Right turning vehicles at Lagmhor

would also have an acceleration lane southbound. Variations to be considered include

keeping Agnes as is with full turning (self regulates as at peak this manoeuvre is already

difficult, or close Agnes right turn out. Safety and efficiency is increased and delays

improved.

Risks: Business risk at Agnes due to Pub and Shell service station access and will need to

be managed in consultation process. Design risk from large vehicle stacking over the rail

crossing (no different to current) but may compromise the projects ability to achieve

outcomes if space not there. Green space will be lost which has public risk.

Programme 5/2: Lagmhor street/SH1left out merge lane. This addresses the traffic

originating from the West trying to turn left on to SH1 by constructing a dedicated left

merge and acceleration lane only.

How it delivers against the outcomes: This treatment would improve network efficiency.

The left turn from the West on to the state highway is significantly better by providing a

means to accelerate and merge and it removes the current situation where a right turning

vehicle at Lagmhor can easily block all traffic waiting to turn left. So this also has a secondary

safety outcome.

Risks: Design consideration required to check large vehicle stacking over the rail crossing

(no different to current) where a dedicated left lane installed. Some parking most likely lost

on the area to North of Lagmhor but this would most likely improve safety. Businesses need

to be managed in consultation process. Some green space will be lost.

Programme 5/3: Manchester Street and Johnstone street: SH1 left in/left out only. This

directs the traffic originating from the East trying to turn right on to SH1 to other

intersections where it is best managed.

How it delivers against the outcomes: This treatment would improve network efficiency

by directing traffic mostly to either of Wilkin or Graham where other works are completed

to improve those intersections. Safety improved for all users as refuges can be installed as

part of blocking state highway access at this location. Already it is noticeable in the traffic

data that users are effectively self-monitoring this anyway but this formally completes it and

removes all risky right turn manoeuvres at peak times.

Risks: Dependant on other intersection improvements being completed first or in concert.

Programme 5/4: Carters Terrace/SH1left in/left out only. This directs the traffic

originating from the East trying to turn right on to SH1 to other intersections where it is

best managed.


by directing traffic to Wilkin where other works are completed to improve this intersection.

Safety improved for all users as refuges can be installed as part of blocking state highway

access at this location. Already it is noticeable in the traffic data that users are effectively

self-monitoring this anyway but this formally completes it and removes all risky right turn

manoeuvres at peak times. A full closure of Carters at SH1 is a variant to this.

Risks: Dependant on other intersection improvements being completed first

Page XI

Programme 5/5: Carters Terrace/SH1left in/left out only and full seagull intersection

treatment at Melcombe Street. This addresses the traffic originating from the West trying

to turn right on to SH1 by constructing a right turn out acceleration lane southbound at

Melcombe.


and safety and achieves all benefit outcomes. As for the above option 5/4, restricting

Carters Terrace or closing altogether are sub-options to investigate and would also improve

safety and efficiency.

(Note for subsequent phases that from the workshops carried out so far that the Police noted

that while the right turn south out of Melcombe is not used by many that this is the only right

turn south able to be made until over the bridge (from the West of Tinwald). Therefore keeping

this is as the status quo is perhaps of a higher importance to maintain than normal (not only

for emergency services), in terms of maintaining accessibility and effective local systems).

Risks: Dependant on other intersection improvements being completed first

Further notes on this programme: A dedicated left merge and acceleration lane for left turn

north out of Melcombe is not thought possible due to the proximity of the bridge and not

enough length to develop a merge. In addition the cycle lane on the state highway is most likely

to be relocated into the green space on the left side and will then need improvement works to

connect in a better way to the existing bridge cycle lanes (both sides). Refer other sections on

cycle lanes in general.

Page XII

Appendix F – Possible Treatments Discussion

Page XIII

Appendix G – 2016 and 2026 Level of service and actual volumes

AM vol AM delay LOS Total delay IP vol IP delay LOS Total delay PM vol PM delay LOS Total delay

Maronan L 95 5 A 475 70 5 A 350 127 5 A 635

R 3 9 A 27 4 9 A 36 5 11 B 55

Hassal L 2 5 A 10 4 5 A 20 2 6 A 12

R 31 11 B 341 43 10 A 430 38 14 B 532

Graham L 9 5 A 45 2 5 A 10 7 7 A 49

R 77 13 B 1001 69 12 B 828 86 20 C 1720

Agnes/Lagmhor Agnes L 0 6 A 0 0 6 A 0 1 8 A 8

T 0 14 B 0 0 13 B 0 0 23 C 0

R 0 15 B 0 0 14 B 0 0 24 C 0

Lagmhor L 117 7 A 819 108 7 A 756 92 8 A 736

T 2 16 C 32 0 15 B 0 0 25 C 0

R 5 14 B 70 2 13 B 26 4 23 C 92

Manchester L 2 7 A 14 1 7 A 7 2 11 B 22

R 49 21 C 1029 0 16 C 0 43 38 E 1634

Wilkin L 2 7 A 14 0 7 A 0 0 11 B 0

R 114 37 E 4218 85 24 C 2040 63 51 F 3213

Carters/Melcombe Carters L 0 7 A 0 0 7 A 0 0 14 B 0

T 0 24 C 0 0 20 C 0 0 46 E 0

R 36 32 D 1152 21 23 C 483 17 56 F 952

Melcombe L 154 15 B 2310 58 9 A 522 81 11 B 891

T 0 20 C 0 0 23 C 0 0 58 F 0

R 0 24 C 0 0 20 C 0 0 46 E 0

Total side

road traffic 698

Total side

road delay 11557

Total side

road traffic 467

Total side

road delay 5508

Total side

road traffic 568

Total side

road delay 10551

(mins) 192.6 (mins) 91.8 (mins) 175.9

2016 Results

Page XIV

AM vol AM delay LOS Total delay IP vol IP delay LOS Total delay PM vol PM delay LOS Total delay

Maronan L 356 512 F 182272 74 6 A 444 33 9 A 297

R 5 512 F 2560 5 14 B 70 8 17 C 136

Hassal L 18 11 B 198 4 6 A 24 2 8 A 16

R 62 820 F 50840 45 16 C 720 119 68 F 8092

Graham L 219 14 B 10 6 A 60 10 8 A 80

R 70 1090 F 129 30 D 3870 107 238 F 25466

Agnes/Lagmhor Agnes L 0 318 F 0 0 8 A 0 0 86 F 0

T 43 318 F 13674 2 25 C 50 68 105 F 7140

R 40 1090 F 43600 31 32 D 992 104 253 F 26312

Lagmhor L 157 387 F 60759 115 11 B 1265 65 34 D 2210

T 1 389 F 389 1 26 D 26 39 41 E 1599

R 7 93 F 651 4 26 D 104 6 61 F 366

Manchester L 132 16 B 2112 2 9 A 18 28 20 C 560

R 31 1021 F 31651 38 46 E 1748 102 263 F 26826

Wilkin L 11 11 B 121 0 9 A 0 1 16 C 16

R 31 1109 F 34379 56 62 F 3472 104 300 F 31200

Carters/Melcombe Carters L 0 27 D 0 0 10 A 0 0 23 C 0

T 6 131 F 786 0 43 E 0 0 117 F 0

R 30 1114 F 33420 32 62 F 1984 101 269 F 27169

Melcombe L 71 957 F 67947 67 17 C 1139 101 127 F 12827

T 0 958 F 0 0 54 F 0 101 127 F 12827

R 13 155 F 2015 0 44 E 0 0 117 F 0

Total side

road traffic 1303

Total side

road delay 527374

Total side

road traffic 615

Total side

road delay 15986

Total side

road traffic 1099

Total side

road delay 183139

(mins) 8789.6 Ratio est. #REF! (mins) 266.4 Ratio est. #REF! (mins) 3052.3

2026 Results

Tinwald Corridor Study - Ashburton · DATE: JAN 2015 DATE:FEB 2015 DATE: FEB 2015 DATE: Revision...

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