Knowsley Local Plan Core Strategy Transport Modelling ... · 301178/ITD/ITN/001/00B 03 October 2012...

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Knowsley Local Plan Core Strategy Transport Modelling

Report

Core Strategy Transport Modelling

October 2012

Knowsley Council


301178 ITD ITN 001 00B

P:\Liverpool\ITD\Projects\301178 Merseytravel Framework 2012-20\CA01-

LCRTM_Application_Knowsley\3.0_Reports\KnowsleyCoreStrategyTestingV1B.doc

03 October 2012

Knowsley Local Plan

Core Strategy Transport Modelling

October 2012

Knowsley Council

Mott MacDonald, 4th floor Royal Liver Building, Pier Head, Liverpool L3 1JH, United Kingdom

T +44(0) 151 236 4343 F +44(0) 151 236 1144, W www.mottmac.com

Knowsley Council 1st Floor Annex Municipal Buildings Archway Road Huyton Merseyside L36 9UX


Knowsley Local Plan Core Strategy Transport Modelling Report

Mott MacDonald, 4th floor Royal Liver Building, Pier Head, Liverpool L3 1JH, United Kingdom

T +44(0) 151 236 4343 F +44(0) 151 236 1144, W www.mottmac.com

Revision Date Originator Checker Approver Description

00A 3 October 2012 MS/MQ NG NG 1st Draft for client review

00B 23 October 2012 MS/MQ MQ NG Final

Issue and revision record

This document is issued for the party which commissioned it

and for specific purposes connected with the above-captioned

project only. It should not be relied upon by any other party or

used for any other purpose.

We accept no responsibility for the consequences of this

document being relied upon by any other party, or being used

for any other purpose, or containing any error or omission which

is due to an error or omission in data supplied to us by other

parties

This document contains confidential information and proprietary

intellectual property. It should not be shown to other parties

without consent from us and from the party which

commissioned it.


301178/ITD/ITN/001/00B 03 October 2012 P:\Liverpool\ITD\Projects\301178 Merseytravel Framework 2012-20\CA01-LCRTM_Application_Knowsley\3.0_Reports\KnowsleyCoreStrategyTestingV1B.doc


Chapter Title Page

1. Introduction 1

1.1 Introduction ________________________________________________________________________ 1 1.2 Outline ___________________________________________________________________________ 2 1.3 Report Structure ____________________________________________________________________ 3

2. Modelling Components 4

2.1 Liverpool City Region Transport Model ___________________________________________________ 4 2.1.1 Objectives _________________________________________________________________________ 5 2.1.2 Structure __________________________________________________________________________ 5 2.1.3 Stage 1: Trip Generation ______________________________________________________________ 6 2.1.4 Stage 2: Mode Choice _______________________________________________________________ 6 2.1.5 Stage 3: Time Period Choice (Macro) ____________________________________________________ 7 2.1.6 Stage 4: Distribution _________________________________________________________________ 7 2.1.7 Stage 5: Departure Time Choice ________________________________________________________ 7 2.1.8 Assignment ________________________________________________________________________ 7 2.1.9 Base year Travel Demand ____________________________________________________________ 7 2.1.10 LCRTM Highway Network and zoning Knowsley ___________________________________________ 8 2.2 Forecasting Travel Demand __________________________________________________________ 10 2.2.1 Forecast years ____________________________________________________________________ 10 2.2.2 Trip Production Forecasts ____________________________________________________________ 10 2.2.3 Trip Attraction Forecasts _____________________________________________________________ 10 2.2.4 Constraint to Trip Productions _________________________________________________________ 11 2.2.5 Outputs __________________________________________________________________________ 11

3. Developments 12

3.1 Introduction _______________________________________________________________________ 12 3.2 Scenarios ________________________________________________________________________ 12 3.3 Development Data _________________________________________________________________ 12 3.4 Non-Knowsley Zones _______________________________________________________________ 17 3.5 Forecast Networks _________________________________________________________________ 17

4. Assessment 18

4.1 Introduction _______________________________________________________________________ 18 4.2 Total Growth in Trips ________________________________________________________________ 18 4.3 Mode Share ______________________________________________________________________ 19 4.4 Growth in Trips ____________________________________________________________________ 20 4.5 Vehicle Kilometres _________________________________________________________________ 21 4.6 Average Trip Length ________________________________________________________________ 22 4.7 Assignment Analysis ________________________________________________________________ 23 4.8 Analysis of the Urban Containment _____________________________________________________ 23 4.9 Flow plots ________________________________________________________________________ 24 4.10 Volume over Capacity Ratios _________________________________________________________ 24 4.11 Change in Link Travel Times _________________________________________________________ 24

Content



5. Conclusions 25

Appendices 26

Appendix A. Core Strategy Development __________________________________________________________ 27 Appendix B. Key to Figures _____________________________________________________________________ 29 Appendix C. Urban Containment _________________________________________________________________ 31 Appendix D. Flow Difference ____________________________________________________________________ 34 Appendix E. Volume over Capacity Ratio (VOC) ____________________________________________________ 37 Appendix F. Link Travel Time ___________________________________________________________________ 40


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1.1 Introduction

The current adopted development plan for Knowsley is the Unitary Development Plan1 (UDP). The Council is currently producing a Local Plan to replace the UDP. It will set out a new strategy for the development of the Borough to 2028 and beyond. The Local Plan will comprise a series of documents that will collectively deal with the spatial issues that will affect people who live, learn and work in the Borough. The overarching document of the Local Plan will be the “Local Plan: Core Strategy”. It is envisaged that the Core Strategy will be submitted to the Secretary of State in early 2013.

A key element of the Core Strategy is to identify the scale of new development to be accommodated in Knowsley. The housing and employment development requirements are set out in the Technical Reports entitled Planning for Housing Growth in Knowsley2 and Planning for Employment Growth in Knowsley3. These were informed by supporting evidence including the Strategic Housing Land Availability Assessment (SHLAA)4 and the Joint Employment Land and Premises Study (JELPS)5.

Drawing upon the evidence presented in these documents, together with a variety of other information sources, the Core Strategy Preferred Options Report (2011) identified the need to deliver a total of 7,650 new dwellings and an additional 65 hectares of employment land during the plan period6.

As part of the SHLAA and JELPS studies, landowners and other stakeholders were given the opportunity to submit details of sites that they considered suitable for development via a “Call for Sites” process. Both the SHLAA and the JELPS studies, however, concluded that there is insufficient suitable land for housing and employment development within the existing urban area of Knowsley to meet these requirements.

The Council therefore explored a number of options for increasing the amount of development that could be delivered within the existing urban area. These included the release of urban greenspace for development, building at higher densities, remodelling and/or intensified development within Principal Regeneration Areas, and transferring some of the Borough's development requirements to neighbouring districts. A number of evidence base studies were produced to examine these options in more detail. The studies include an audit of urban greenspaces7 to examine the potential to release such areas for development, a Liverpool City Region-wide study of land supply and

_________________________ 1 Knowsley Replacement Unitary Development Plan (Knowsley MBC, 2006)

2 Technical Report: Planning for Housing Growth in Knowsley (Knowsley Council, 2012)

3 Technical Report: Planning for Employment Growth in Knowsley (Knowsley Council, 2012)

4 Knowsley Strategic Housing Land Availability Assessment – 2012 Update (Knowsley Council, 2012)

5 Joint Employment Land and Premises Study (BE Group, 2010)

6 The plan period for the preferred Options report was up to 2027. As it is now envisaged that the Core Strategy will be adopted in 2013 the plan period has been extended to 2028.

7 Greenspace Audit (Knowsley Council, 2012)

1. Introduction


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requirements for new development8, and a study which explored the potential of the remodelling of land in Knowsley Industrial and Business Parks9. After considering the options, the Council considers that although these options may be able to meet some of the Borough’s future development needs, they will not be able to meet all of them. The

Council therefore concluded that the release of some land that is presently within the Green Belt will be required to meet the shortfall in the Borough’s future development needs.

A study was undertaken to identify land in the Green Belt that has the potential to be developed10. This study adopted a staged approach to rule out parts (known as parcels) of land in the Green Belt that either must be kept open in order to maintain the integrity of the Green Belt, or which were considered to be unsuitable for development. The Green Belt Study process therefore resulted in several locations around the Borough being identified as the most appropriate for new development taking account of the five purposes of including land in the Green Belt contained in Planning Policy Guidance Note 2 (PPG2): Green Belts11.

1.2 Outline

Mott MacDonald has been commissioned by Knowsley Council to assess the transport impacts of development proposals within their emerging Core Strategy. In undertaking this work, Mott MacDonald has utilised the Liverpool City Region Transport Model (LCRTM), which has been set up to run and compare two distinct development scenarios:

i) Urban Containment scenario comprising historic trends rolled forward plus the development of sites allocated in the Knowsley’s Unitary Development Plan, sites under construction, sites with the benefit of planning permission, and sites considered suitable for development in the SHLAA and JELPS studies; and

ii) Core Strategy scenario comprising sites included in the Urban Containment scenario plus development at locations currently in the Green Belt that are being considered for development in the Local Plan: Core Strategy.

LCRTM has been used to provide an indication of where congestion and delay on the highway network is likely to occur (referred to as hot spots) as a result of development in locations being progressed in the Local Plan: Core Strategy.

_________________________ 8 Liverpool City Region Housing and Economic Development Evidence Base Overview Study (2011)

9 Delivering a New Future for Knowsley Industrial Park – Strategic Framework (2011)

10 Draft Knowsley and Sefton Green Belt Study – Knowsley Report (2011)

11 The key elements of PPG2, including the five purposes of including land in the Green Belt, now form

part of the National Planning Policy Framework.


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1.3 Report Structure

Following this introduction, the report is split into four further chapters: Chapter 2 provides information on the structure of LCRTM, what it was designed to do

and its component parts. The forecasting process is also described in terms of how future years’ travel demand is estimated and the inputs that are required for this;

Chapter 3 summarises the forecast development scenarios and how these have been accounted for in the model set up;

Chapter 4 contains a summary and explanation of the model results; and Chapter 5 presents the study’s conclusions.


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2.1 Liverpool City Region Transport Model

The Liverpool City Region Transport Model (LCRTM) is a multi-modal transport model, comprising a link-based highway model, a public transport model and a variable demand model. It is the primary assessment tool for testing various transport intervention measures in the City Region.

The geographical scope for the model includes the Liverpool City Region as the main study area together with areas of West Cheshire, West Lancashire and Warrington, and a buffer area beyond extending further into Lancashire and areas of Greater Manchester and North Wales (see Figure 2.1).

Figure 2.1: Geographical scope of LCRTM

Source: LCRTM Highway Model Local Model Validation Report – December 2009

2. Modelling Components


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LCRTM has a base year of 2008 – that is it is representative of travel demand and conditions in 2008. The model has been used for appraising measures within Merseyside’s Third Local Transport Plan (LTP3), which became active in April 2011.

The model was updated in August 2011 to incorporate new traffic data into the highway model, although the model retained its 2008 base year. Since then, prominent applications of the model have included supporting Merseyside’s Local Sustainable Transport Fund (LSTF) bid and more recently associated bidding for the Better Bus Area Fund (BBAF), which secured funding of £20M and £4M respectively for the region from the Department for Transport (DfT).

2.1.1 Objectives

LCRTM has been designed to address the following objectives: to produce a long term forecast of growth in demand for travel in the region, which

will reflect changes to land use, demographics, employment and the economy; to forecast the impacts of growth and changes in demand for travel on the existing

highways and public transport networks; to forecast the impacts of specific major regeneration projects and major land

use developments on the transport system in the Liverpool City Region; to forecast the impacts of increased congestion on the local economy and quality of

life; and to examine an array of measures and interventions that could be deployed to

mitigate traffic/travel growth impacts.

2.1.2 Structure

LCRTM follows the Department for Transport (DfT) guidance WebTAG in respect of its components and structure. The model system operates within CUBE Voyager12 software, using applications and bespoke scripting of processes such as the assignment methodology and the variable demand model.

The general structure of LCRTM is explained in Figure 2.2, illustrating the hierarchy of travel choices that fall between trip generation and assignment. At each level in the hierarchy the travel choice is dependent upon the change in cost of travel from the base year to the forecast year. The highway and public transport models, which are the final stage in the model are concerned with the assignment (routing) of vehicles and passengers throughout the transport system, whilst the demand model deals with the traveller choices in terms of mode choice (how to travel), time period choice (when to travel) and distribution (where to travel).

_________________________ 12

Cube Voyager is the name of a commercially available software package produced by Citilabs for use in transport modelling.


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Figure 2.2: Overall LCRTM 5-Stage Model Structure

Source: LCRTM Demand Modelling Report – August 2010

2.1.3 Stage 1: Trip Generation

Trip Generation is a measure of the total demand for travel across all destinations, time periods and modes. It is split by journey purpose, for example journeys to work (commuting), journeys in the course of work (employers business) and other (such as shopping, education and leisure related trips). A further discussion on the mechanism used to forecast the total demand for travel is provided in Section 2.2.

2.1.4 Stage 2: Mode Choice

Subsequent to trip generation the total travel demand is then split across three travel modes: public transport (comprising of bus and rail), car, and slow modes (comprising walk and cycle).


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2.1.5 Stage 3: Time Period Choice (Macro)

The model has four discrete time periods: the morning peak period (07:00-10:00); interpeak (10:00-16:00), evening peak period (16:00-19:00) and the off peak (19:00-07:00).

2.1.6 Stage 4: Distribution

Trips by purpose, mode and time period are then distributed to destinations within the model.

2.1.7 Stage 5: Departure Time Choice

Within the morning peak period, the model splits the number of trips in the three hour AM peak period into three one-hour periods, comprising of a pre-peak (07:00-08:00), peak (08:00-09:00), and post-peak hour (09:00-10:00).

2.1.8 Assignment

This concerns the routing of passengers on the public transport network, that is which bus and rail services they use to connect their trip origin and destination. For car users, it is the choice of roads that connect each end of their journey. In both cases, route choice is based on travellers using the cheapest cost route, based on factors such as fares, waiting times, travel times and fuel costs.

In terms of the highway model, three vehicle classes are assigned: cars, light goods vehicles (LGV) and other goods vehicles (OGV). The car vehicle class is further sub-divided into three journey purposes: commuting, employers business and other. Only the peak hours (08:00-09:00 and 17:00-18:00) and the average interpeak (between 10:00-16:00) are subject to assignment.

2.1.9 Base year Travel Demand

As stated LCRTM currently has a base year of 2008. The total demand for travel in 2008, and the respective origin and destination of trips in the City Region has been developed using a number of sources including: from historical roadside interview data collected across the region; from information derived from Merseyside Travel Survey (HTS) on household trip

rates; and land-use indicators, such as statistics on total employment, retail employment and

educational places.

An update to the LCRTM highway model was undertaken in 2011 during which the roadside interview (RSI) data collected in 2009 in Wirral and Liverpool were incorporated into the model, thus improving the representation of trips to and from these areas of the model. The base year of the model was left unchanged.


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2.1.10 LCRTM Highway Network and zoning Knowsley

LCRTM comprises of 459 model zones, 35 of which are located within Knowsley’s administrative boundary as shown in Figure 2.3. The zoning system has been developed based on Census Output Area boundaries, which have then been aggregated.

The coverage of the highway network in Knowsley and adjacent areas is also shown in Figure 2.3 (where the black lines show the links included in the model). All motorways, A-roads, B-roads and significant C-roads are included, thus providing a good coverage of the major routes between trip origins and destinations in the district. The LCRTM highway network is link based and the representation of delay to highway vehicles is undertaken by the use of speed flow curves. There is no explicit junction modelling in the current version of LCRTM, hence the analysis of impacts on junctions cannot be assessed.


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Figure 2.3: LCRTM Network and Zone System Coverage

Source: LCRTM_Coverage_Knowsley_Low_Res.pdf

Contains Ordnance Survey Data (c) Crown copyright and database right 2012


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2.2 Forecasting Travel Demand

Changes in travel demand arise from: population growth, through:

Housing development Changes in the occupancies of households;

location and volume of employment, including strategic development sites Regeneration and economic activity; and

changes in car ownership.

These features are all represented in LCRTM’s approach to forecasting future travel demand.

2.2.1 Forecast years

The default forecast years for LCRTM are 2014 and 2024. For the purpose of the current study the latter forecast year has been used as a proxy for the end of the plan period.

2.2.2 Trip Production Forecasts

Forecasts of trip productions are split into three broad categories: The number of home based trips: The quantum of home based trips are based on the

changes in the number of households taking into account Government forecasts in terms of compositions of households and car ownership, which are then combined with the trip generation rates derived from the Merseyside Household Travel Survey (HTS).

Non-home based trips: Non home based trips, for example a trip made from a place of work on business, are estimated based on information in the HTS on the propensity for making a non-home based trip, which is then applied to the non-home end of a home based trip.

Freight: the growth in freight is based on the growth in total employment.

2.2.3 Trip Attraction Forecasts

Within LCRTM, attraction forecasts are based on future year estimates of: total employment; retail employment; pupils; and population.

These estimates are undertaken at zonal level and then used to distribute the trip productions prior to the demand model being run. For example, home based commuting trips are distributed according to the location and scale of total employment, whilst trips associated with education and shopping are distributed according to Government forecasts on pupil numbers and retail employment respectively.


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2.2.4 Constraint to Trip Productions

It is important to note that forecasting within LCRTM is primarily a home-based forecast, recognising the fundamental building block of trip generation is the household unit. Whilst databases such as TRICS13 are often used to develop estimates of the trips into and out of development sites, the default approach taken in LCRTM is to estimate the total number of trips generated by the household unit, which is then distributed across the various trip attractions. Hence, the number of journeys to work in the model, for example, is governed not by the number of employment places, but by the number of journey to work trips created by all the households. In general terms, the number of employment places is only used as a weight to distribute the commuting trips across the modelled zones.

2.2.5 Outputs

The forecasting of trips is undertaken in a separate LCRTM module, contained within an Access Database: the External Forecasting Model (EFM). The outputs from EFM are future year trip matrices that are based on travel costs remaining unchanged from those in the base year – these are termed reference case matrices.

When assigned to the transport network the reference case matrices result in changes to travel costs (through increased congestion from increased traffic levels) compared to the base year model. The response to these cost changes in terms of the mode, destination and time period choices, are determined within the demand model. The output from the demand model is a new set of assignment matrices that reflect the changes to travel costs resulting from future increases in travel demand. This can be used to estimate the impact of developments on the transport network.

_________________________ 13

TRICS is a commercially available database system which allows its users to establish potential levels of trip generation for a wide range of development and location scenarios. TRICS is widely used as part of the planning application process by both developers and local authorities.


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3.1 Introduction

In this chapter the development scenarios that have been tested in Liverpool City Region Transport Model (LCRTM) are described.

3.2 Scenarios

Two development scenarios have been modelled in LCRTM, namely: 1. The Urban Containment scenario comprising historic trends rolled forward plus

development of sites allocated in the Knowsley’s Unitary Development Plan, sites under construction, sites with the benefit of planning permission, and sites considered suitable for development in the SHLAA and JELPS studies; and

2. The Core Strategy scenario comprising sites included in the Urban Containment scenario plus development at locations currently in the Green Belt that are being considered for allocation for development in the Local Plan: Core Strategy.

3.3 Development Data

In view of the forecasting mechanism utilised in LCRTM, Knowsley Council provided bespoke projections in terms of the predicted growth in housing and employment and retail employment within Knowsley. The information is summarised in Tables 3.1 to 3.3.

From the base year (2008) to 2024, Knowsley’s data indicates a growth of 9,321 households14 to be considered under the Local Plan: Core Strategy; however it is important to note that nearly six thousand of these are expected to be developed under the Urban Containment scenario.

In terms of employment, an additional 6,529 employment opportunities have been allotted to land being considered for employment purposes. In terms of the treatment within the model, the employment data has been used to update the distribution of the overall employment growth for Knowsley as predicted in the “Aspirational” forecast for the City Region made by Cambridge Econometrics/PION in 2009 (on behalf of the Merseyside Partnership)15 for the third Local Transport Plan. Hence, employment growth in the Urban Containment and Core Strategy scenarios is consistent in absolute terms, but the distribution of this growth is different based on the differences in the identified employment sites under the respective scenarios.

Figures 3.1 and 3.2 show the location and scale of the additional housing units, whilst Figure 3.3 shows where the new employment opportunities are being considered.

_________________________ 14

This figure differs from the Core Strategy because this study considers different base dates and the development and the Core Strategy contains a risk assessment of deliverability of sites.

15 Economic Forecasts for the Liverpool City Region: Recession and Recovery. Technical Report. PION Economics and Cambridge Econometrics, December 2010.

3. Developments


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Appendix A shows how the increased households and change in employment distribution is represented within the LCRTM zone system for Knowsley.


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Table 3.1: Knowsley District - Agreed Changes to Land-Use Projections for period between 2008 and 2024

Scenario Household Units

Net Change Employment (all) Number of Jobs

Retail Employment Number of Jobs

Urban Containment 5,989 - -

Core Strategy 9,321 6,529* -

Source: Land-use projections as supplied and agreed by Knowsley District Council * Note: The change in Core Strategy employment job numbers has been represented as a redistribution change across Knowsley district, with Core Strategy totals constrained to Urban Containment totals.

Table 3.2: Knowsley District - Land-Use Projection Totals - Comparison between 2008 Base Year and 2024 Urban Containment

Scenario Household

Units Employment (all) Number of Jobs


2008 Base Year 71,697 61,420 11,444

2024 Urban Containment 77,685 68,763 12,429

Difference 5,989 7,343 985

Source: LCRTM External Forecasting Module

Table 3.3: Knowsley District - Land-Use Projection Totals - Comparison between 2008 Base Year and 2024 Core Strategy

Scenario Household

Units Employment (all) Number of Jobs


2008 Base Year 71,697 61,420 11,444

2024 Core Strategy 81,017 68,763* 12,429

Difference 9,321 7,343* 985

Source: LCRTM EFM Database (GH Scenario) * Note: Core Strategy employment totals (including retail employment) have been constrained to Urban Containment totals, following a redistribution of job numbers across Knowsley district.


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Figure 3.1: Location and scale of additional housing units: Urban Containment compared to base.

Figure 3.2 Location and scale of additional housing units: Core Strategy scenario compared to base



16


Figure 3.3: Location and scale of additional employment



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3.4 Non-Knowsley Zones

The household and employment growth used in the City Region outside of Knowsley is consistent to that adopted in the version of LCRTM used to appraise the third Local Transport Plan (LTP3). Hence, for employment, projections and major employment sites are consistent with the “Aspirational” forecast for the City Region made by Cambridge Econometrics/PION in 2009 (on behalf of the Merseyside Partnership)16 used in LTP3.

The LTP3 forecast included the addition of major employment sites such as Liverpool Waters (Liverpool), Parkside (St Helens) and Daresbury (Warrington). These have all been included within the Core Strategy Scenario.

The housing projections outside of Knowsley are those agreed during consultations with each Merseyside district in 2011 and are thus representative of the best forecasts available at that time.

3.5 Forecast Networks

Transport Networks have been developed for the two scenarios namely an Urban Containment and a Core Strategy scenario for each of the assessment years.

The following committed schemes with respect to their opening years have been added to the base networks to form the 2024 Urban Containment and Core Strategy networks: Hall Lane Strategic Gateway;

Tarbock Island (Junction 6 of M62);

A5117 Deeside Park Junctions Improvement;

A5300/A562 Speke Road Improvement;

Mersey Gateway: Second Mersey crossing in Halton;

Switch Island: Thornton Link Road; and

North West Triangle rail electrification (Liverpool-Manchester and Liverpool-Wigan).

_________________________ 16

Economic Forecasts for the Liverpool City Region: Recession and Recovery. Technical Report. PION Economics and Cambridge Econometrics, December 2010


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4.1 Introduction

In this chapter the results from running LCRTM for the Urban Containment and Core Strategy scenarios are presented.

In the first instance, the total growth in trips as a result of the Core Strategy scenario is presented. Further analysis reviews the impact of the Core Strategy assumptions on mode share, followed by statistics on the total vehicle kilometres and average trip distances.

The final stage of the LCRTM is the assignment of the travel demand on the highway (and public transport networks) after all the travel choices within the demand model have been taken into account. For the purpose of the study the analysis of the assignment impact has focused on the morning peak hour (08:00-09:00) and evening peak hour (17:00-18:00) at a forecast year of 2024.

Using the model outputs, the “hot spots” in terms of the location of significant increases in traffic volumes and volume over capacity (V/C) ratios as well as travel times can be identified. Since LCRTM is a link based model, it is not currently possible to capture the impact of the developments on the operation of junctions. However, by determining where the level of traffic growth is at its greatest, the areas where impacts on junctions are likely can be identified.

4.2 Total Growth in Trips

Table 4.1 shows the overall growth in trips for commuting (Commute), employers business (EB) and other. At the 24-hour level, it compares the Core Strategy (CS) and the Urban Containment (UC) scenarios. Based on all trip purposes, there is 3% increase in trips to and from Knowsley to the rest of the LCRTM study area. This represents around 12,000 additional trips, per weekday, in each direction.

4. Assessment


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Table 4.1: 24-hour Trip Generation

Commute Other EB Total Commute Other EB Total

Trips From Knowsley 1,223 5,859 86 7,168 2% 3% 0% 3%

Trips To Knowsley 1,115 5,656 249 7,020 2% 3% 1% 2%


Trips From Knowsley 163 1,300 13 1,477 2% 3% 2% 3%

Trips To Knowsley 219 1,253 20 1,492 2% 3% 3% 3%


Trips From Knowsley 375 3,183 47 3,605 5% 4% 4% 4%



Trips From Knowsley 1,762 10,342 146 12,250 2% 3% 1% 3%

Trips To Knowsley 1,703 10,089 314 12,107 2% 3% 1% 3%

Difference (CS-UC) % Difference




Highway

Public Transport

Active Modes

Total

4.3 Mode Share

Tables 4.2 and 4.3 show the mode share for travel for all trips with at least one end of their journey in Knowsley (that is a journey that starts, ends or is completely within Knowsley).

It can be seen that there is very little difference in the mode share between the Urban Containment and Core Strategy scenarios in AM peak hour, with around 68% of all trips being by car, and 15% by public transport. During the PM Peak it is around 72% by car and 13% by public transport.

Table 4.2: AM Peak hour Mode Share

AM Car Freight Public Transport

2008 (Base) 70.6% 10.5% 18.9%

2024 Urban Containment 67.8% 17.5% 14.7%

2024 Core Strategy 68.0% 17.2% 14.8%

Table 4.3: PM peak Mode Share

PM Car Freight Public Transport

2008 (Base) 74.8% 9.0% 16.2%

2024 Urban Containment 72.3% 14.4% 13.3%

2024 Core Strategy 72.5% 14.1% 13.4%


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4.4 Growth in Trips

Tables 4.3 to 4.7 present the change in the number of trips in each hour of the AM peak period and for the PM peak period between the Urban Containment and Core Strategy scenarios.

Over 50% of the growth in the AM peak period occurs in the hours before and after the traditional peak of 08:00-09:00. It can be seen that in the AM peak period, there are nearly 600 extra trips from Knowsley in the pre-peak hour (07:00-08:00) and an increase of nearly 1,200 trips in the actual peak hour itself (08:00-09:00). In the post peak hour (09:00-10:00) there is an increase of around 700 trips. Hence, one effect of development in the Green Belt locations is to increase the number of trips that are made either side of the peak hour – or peak spreading as it is typically referred to. In fact, the percentage growth is greater either side of the peak hour than during the peak hour itself. Table 4.4: Growth in Trips: 07:00-08:00


Trips From Knowsley 405 94 37 537 4% 4% 5% 4%

Trips To Knowsley 91 58 24 172 1% 2% 2% 1%







Total


Highway


Public Transport


Table 4.5: Growth in Trips: 08:00-09:00



Trips To Knowsley 37 367 -1 403 0% 2% 0% 1%



Trips To Knowsley -1 92 0 91 0% 3% 1% 2%


Trips From Knowsley 415 749 16 1,180 4% 3% 1% 3%


Total


Highway


Public Transport



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Table 4.6: Growth in Trips: 09:00-10:00










Total


Highway


Public Transport


Table 4.7: Growth in Trips (16:00-19:00)


Trips From Knowsley 30 1,044 -49 1,024 0% 3% -1% 2%






Trips From Knowsley 33 1,235 -47 1,220 0% 3% -1% 2%


Total


Highway


Public Transport


4.5 Vehicle Kilometres

Tables 4.8 and 4.9 show the impact of the Core Strategy scenario on total vehicle kilometres travelled for trips with at least one end of their journey in Knowsley. From the impact reported for 2024 AM peak it can be seen that overall, there is a 0.1% decrease in vehicle-kilometres for all highway trip purposes. The decrease in car employer’s business and car commute travel are contributors to the overall decrease in vehicle kilometres. However, there is an increase of 1.9% percent reported for other trips.

There is a marginal increase in distance travelled during PM Peak with an overall increase of 0.7% in vehicle kilometres travelled. The increase in distance travelled by car for other than commuting purposes is 1.8%, which is consistent with the AM Peak. However, a reduction of 1.4% is observed in distance travelled by other goods vehicles.


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Table 4.8: 2024 AM Vehicle Kilometres

AM Car -

Commute Car- Other

Car -Employer’s

Business

Light Goods

Vehicles

Other Goods

Vehicles Total

2008 Base 227,308,623 95,943,548 53,463,041 54,476,638 44,296,558 475,488,408

2024 Urban Containment 266,231,365 103,231,916 56,837,058 81,736,721 50,557,925 558,594,986

2024 Core Strategy 265,758,520 105,230,142 56,412,404 81,859,037 50,822,960 560,083,063

Absolute Difference -472,846 1,998,226 -424,654 122,316 265,035 -482,389

Difference (Core Strategy minus Urban Containment) -0.2% 1.9% -0.7% 0.1% 0.5% -0.1%

Table 4.9: 2024 PM Vehicle Kilometres

PM Car -

Commute Car- Other

Car -Employer’s

Business

Light Goods

Vehicles

Other Goods

Vehicles Total

2008 Base 216,238,092 122,131,214 47,824,206 50,781,873 23,920,997 460,896,383

2024 Urban Containment 248,896,557 148,297,446 55,471,136 75,796,248 27,250,270 555,711,658

2024 Core Strategy 249,862,897 150,907,896 55,566,178 76,112,296 26,881,472 559,330,739

Absolute Difference 966,340 2,610,449 95,042 316,049 -368,798 3,619,081

Difference (Core Strategy minus Urban Containment) 0.4% 1.8% 0.2% 0.4% -1.4% 0.7%

4.6 Average Trip Length

Tables 4.10 and 4.11 show the average length of a trip in the AM and PM peak hours. It can be seen that development in the Green Belt locations is predicted to result in a slight reduction in the average trip length. This also suggests that although there is an increase in the demand for travel as a result of developing within the current Green Belt, the locations do not lead to longer journeys.

Table 4.10: Average Trip Length: AM Peak Hour

AM 2008 Average Trip

Distance (km) 2024 Average Trip

Distance (km)

Urban Containment 6.7 13.0

Core Strategy 6.7 12.8

% Change N/A -1.0%


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Table 4.11: PM Average Trip Length: PM Peak Hour

PM 2008 Average Trip

Distance (km) 2024 Average Trip

Distance (km)

Urban Containment 15.6 14.0

Core Strategy 15.6 13.9

% Change N/A -0.5%

4.7 Assignment Analysis

The assignment of the 2024 Urban Containment and Core Strategy highway matrices have been compared to identify the likely hot-spots in terms of the impact on network performance in Knowsley as a result of implementing the Core Strategy scenario.

In the first instance, an analysis has been undertaken of the performance of the Urban Containment scenario – that is to determine the impact of forecast developments that do not include Green Belt locations.

Following the analysis of the Urban Containment, three different measures have been used to show where, as a result of increases in traffic over the Urban Containment, there may be additional performance issues in terms of the delay experienced by road users.

The following analyses have been undertaken: Identifying where absolute flow changes could be considered to be materially

significant. This has been based on identifying those links where the increase in flow under the Core Strategy scenario is greater than 5% with a corresponding change in flow of more than 50 vehicles per hour.

Identifying where the volume over capacity ratio in the Core Strategy scenario exceeds 85% on a link that in the Urban Containment was less than 85%; that is where capacity is close to being exceeded and likely to cause congestion when developing in the Green Belt locations.

Identifying where the link travel time in the Core Strategy scenario is 5% greater than the travel time in the Urban Containment scenario, and the absolute change in travel time is greater than one minute.

A series of outputs from the model are presented in Appendices C to F. A plot is provided in Appendix B to illustrate key road names to aid in the interpretation of the figures.

4.8 Analysis of the Urban Containment

Appendix C shows that, under the Urban Containment scenario, by 2024 many links in Knowsley are expected to have a volume over capacity ratio (V/C) exceeding 85%. Whilst a V/C ratio of 100% indicates a road at capacity, anything above 85% is indicative of a road approaching capacity, where congestion and negative impacts on journey times can be expected.


24


The main point to take from this analysis is that even without the development in the Green Belt locations there are areas in Knowsley where the road network is forecast to be reaching capacity.

4.9 Flow plots

Appendix D shows the locations where the traffic flow exceeds the Urban Containment by 5% and by more than 50 vehicles. It can be seen by cross reference to Figures 3.1 and 3.2 that these hot spots are consistent to the areas seeing the biggest change in the number of households.

4.10 Volume over Capacity Ratios

Appendix E shows the links where the volume over capacity (V/C) in the Core Strategy scenario is greater than 85% where it was less than 85% in the Urban Containment scenario.

When compared to the Urban Containment scenario, there are relatively few additional locations where the volume over capacity ratio is greater than 85% (100% being operating at capacity) with the Core Strategy. This indicates that development in the Green Belt locations is unlikely to have wide-ranging impacts on the performance of the highway network in both the AM and PM peak hours over and above what would be expected in the Urban Containment scenario.

4.11 Change in Link Travel Times

Appendix F shows the links where journey times are expected to increase by over 5% and one minute in the Core Strategy scenario compared to the Urban Containment scenario. As expected, the locations where journey times are expected to increase are broadly consistent with where the increase in the number of journeys is at its greatest.


25


This study compares the effect of development in locations in the Green Belt (Core Strategy scenario) over and above development that is expected to occur within the urban area (Urban Containment scenario). It uses the Liverpool City Region Transport Model (LCRTM) which contains modelling of traffic growth to 2024 which has been used as a proxy for the end of the plan period for the Local Plan: Core Strategy.

In the Urban Containment scenario many roads in Knowsley will have a volume over capacity ratio in excess of 85% in the morning and evening peak hours. This means that there will be potential network issues even without additional traffic from development in the Green Belt locations. When considering the Core Strategy scenario, the modelling has not taken into account the highway improvements that might be implemented to mitigate against the Urban Containment scenario impacts.

The model predicts that, in 2024, there will be a small number of locations on the network that are likely to exhibit noticeable increases in traffic and reduction in available capacity compared with the Urban Containment scenario. The model also suggests that over 50% of the growth in traffic in the AM peak period is a result of growth in travel outside of the peak hour itself dampening down the peak hour impact of the developments by spreading the peak hours.

At the locations where the increase in flows is greater than 5% in the AM and PM peak hours, the analysis shows that the Core Strategy scenario in general has little additional impact on the capacity remaining on these roads. That is not to say, however, that junction delays will be insignificant. It should be recognised that the model works at a high level and whilst this will give a good regional analysis, these findings will require more detailed analysis at the local level for issues specific to Knowsley’s network.

The issues highlighted in this study should only be seen as an indication of potential network areas which will need to be considered in detail by developers of the sites. In summary a more detailed modelling approach would be required to examine the operation of junctions in these areas.

However, the model outputs suggest that the “hot-spots”, in terms of the additional impact of the Core Strategy scenario on the highway network performance, are likely to be limited to discreet areas of the Borough and unlikely to have notable impact on the wider road network. It is expected that targeted junction improvements combined with demand management measures such as enhancements to public transport services would provide mitigation against these impacts. It is also anticipated that the developers wishing to develop the area would fund the cost of the improvement measures required by their development and this report be utilised to provide a framework of the likely areas to be considered at such time. It is further expected that these measures would be in addition to any improvements that are put in place to address the impacts of the Urban Containment scenario.

5. Conclusions


26


Appendix A. Core Strategy Development __________________________________________________________ 27 Appendix B. Key to Figures _____________________________________________________________________ 29 Appendix C. Urban Containment _________________________________________________________________ 31 Appendix D. Flow Difference ____________________________________________________________________ 34 Appendix E. Volume over Capacity Ratio (VOC) ____________________________________________________ 37 Appendix F. Link Travel Time ___________________________________________________________________ 40

Appendices


27


Appendix A. Core Strategy Development


28


Figure A.1: Household Projection at LCRTM zonal level: Difference between Core Strategy and Urban Containment

Figure A.2: Employment Projection at LCRTM zonal level: Difference between Core Strategy and Urban Containment.



29


Figure B.1 shows a selection of key road names in Knowsley in relation to LCRTM’s representation of the road network. This image is provided to aid readers in the interpretation of subsequent illustrations.

Appendix B. Key to Figures


30


Figure B.1: Key Road Names

Source: <Insert Source here or delete this table row>

A580

M62

A5300

M57A58

A57

A562

M62

J7

A5080

M62

J6

M62

J6

A57

B5202

M57

A57

M57

J2

M57

J3

M57

J4


31


The following plots show where the link volume over capacity (V/C) ratio in the Urban Containment scenario exceeds 85%.

Links meeting this criterion are highlighted by thick red lines.

Figures C.1 and C.2 refer to the AM and PM peak at 2024 respectively.

Appendix C. Urban Containment


32


Figure C.1: AM 2024 Urban Containment: Links with VOC > 85%



33


Figure C.2: PM 2024 Urban Containment: Links with VOC > 85%



34


The following plots show where the absolute change in traffic flow as a result of the Core Strategy could be considered materially significant. This has been based on identifying those links where the increase in traffic is greater than 5% with a corresponding change in flow of more than 50 vehicles per hour.


Figures D.1 to D.2 show the 2024 AM and PM forecasts respectively.

Appendix D. Flow Difference


35


Figure D.1: AM Flow Difference

Knowsley Lane

A57 Liverpool Road

A526 Seth Powell

Way

Hall Lane

Licker's Lane

Church Road

A562 Higher

Road

Windy Arbor Road

Dragon Lane

Stockbridge Lane

A57

Higher

Road

Finch Lane


36


Figure D.2: PM Flow Difference

Knowsley Lane

A526 Seth Powell

Way

A562 Higher

Road

Windy Arbor Lane

Dragon Lane

Stockbridge Lane

Old Lane

Blue Bell Lane

A57 Warrington

Road

Portico Lane


37


The following plots show where the volume over capacity (V/C) in the Core Strategy scenario is greater than 85% when in the Urban Containment it was less than 85%. That is to say the analysis identifies where the implementation of the Core Strategy is likely to cause a link to become close to capacity.


Figures E.1 and E.2 refer to the AM and PM peak respectively.

Appendix E. Volume over Capacity Ratio (VOC)


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Figure E.1: 2024 AM – V/C Core >85% where V/C Do Min <85


A526 Seth Powell

Way

Old Lane

Church Road

Huyton Lane

A57


39


Figure E.2: 2024 PM – V/C Core >85% where V/C Do Min <85

Knowsley Lane

A561

Dragon Lane

A57 Warrington

Road


40


The following plots show where the link travel time in the Core Strategy exceeds the Urban Containment travel time by 5% and the absolute difference is greater than one minute.


Figures F.1 and F.2 refer to the AM and PM peak respectively.

Appendix F. Link Travel Time


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Figure F.1: 2024 AM – Increase in link travel time > 5% and 1 Minute


Knowsley Lane

A526 Seth Powell

Way

Hall Lane

Licker's Lane

Lower Road

Dragon Lane

Stockbridge Lane

A57 Warrington

Road

Pilch Lane

Cambell

Drive

Old Lane

Bentham Drive

Childwall Valley

Road

Portico Lane


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Figure F.2: 2024 PM – Increase in link travel time > 5% and 1 Minute

Knowsley Lane

A526 Seth Powell

Way

Smithy Lane

Blue Bell LaneDragon Lane

Stockbridge Lane

A57 Warrington

Road

Rocky Lane

Finch Lane

Portico Lane


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Knowsley Local Plan Core Strategy Transport Modelling ... · 301178/ITD/ITN/001/00B 03 October 2012...

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