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Interim Advice Note 111 09Managed Motorways implementation guidance Hard shoulder running

IAN 111/09 Nov 09


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IAN 111/09 Nov 09

INTERIM ADVICE NOTE 111/09

Managed Motorwaysimplementation guidance Hardshoulder running

Summary

Provides guidance on implementation ofManaged Motorways schemes incorporatingHard Shoulder Running (HSR)

Instructions for Use

This document replaces IAN 111/08


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Amendments

The main changes from IAN 111 Version 1 (May 30th2008) are:

(NB References are to sections within this document)

Section 1.2.1 indicates that there are now mandatory sections of the document

identified by black boxes.

Section 1.2.2 there is now no requirement to contact HA NetServ regarding the

implementation of MM-HSR on D4M and D5M. Revised guidance on the evaluation

(fit for purpose) of existing features with regard to the proposed scheme.

Section 3.5 advice is now provided on the minimum length of MM-HSR link and

opening long links.

Section 5.4.1 updated advice on scoping the likely impacts for:

o Disruption due to construction

o Ecology and Nature Conservation

o Traffic Noise and Vibration

o Water Quality and Drainage

Section 5.5 updated advice on potential generic mitigation strategies

Section 5.7 updated advice on drainage design philosophy with regard to flow

widths.

Section 6 reference to Project Safety Risk Management (PSRM) updated along

with advice concerning the level of Safety Management required for Managed

Motorway Schemes.

Section 7 substantially updated.

Section 8.4 updated to reflect that the expected maximum speed of operation of the

hard shoulder when it is opened to traffic will be 60mph (Figures 8.6 and 8.7 revised).Also revised advice about the use of legends on MS4s and clarification on application

of close proximity rules. Figures 8.10 and 8.11 revised for clarity.

Section 8.5 substantially revised guidance on the fixed signing at entry and exit to

an MM-HSR scheme.

Section 8.7.1 reference made to IAN 68/05 and IAN 75/06.

Section 8.11 section reduced national guidance is available from the Highways

Agency.

Section 8.12 further guidance added for Ramp Metering.


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Section 9.1 revised advice on Site Data.

Section 9.2 revised advice on the Transmission System

Section 9.3 additional advice on the Control System

Section 9.4 new guidance on Power Issues

Section 9.5 further advice on Combined Equipment Cabinets

Section 9.8 Advice provided on the provision of mock enclosures and road

markings for HADECS

Section 9.10.1 new advice on the use of Strategic VMS (MS3s)

Section 9.11 revised advice on Ambient Light Monitors

Section 9.12 revised section on MIDAS

Section 9.13 revised advise on ERA Detection and Monitoring

Section 9.16 new advice on Ramp Metering

Section 9.17 Brief note provided on commissioning of equipment

Section 10.1 new advice on Piers, Parapets and Gantries

Section 10.2 new advice on Headroom and Clearance

Section 10.3 new advice on Railway Infrastructure Considerations.

Section 10.4 new advice on alignment

Section 10.5 new advice on Permanent Traffic Signs including Driver Location

Signs and Hard Shoulder Ends signs

Section 10.6 revised advice on drainage

Section 10.7 additional advice provided on Lane Widths

Section 10.9 additional advice on carriageway issues

Section 10.10 revised advice on signal gantry frequency

Section 10.11 revised advice on gantries in the vicinity of junctions especially in

relation to TD46/05 and IAN 87/07 and long merges.

Section 10.11.1 new advice on gantries in the vicinity of motorway service areas.

Section 10.13 revised advice on ERAs

Section 10.15 revised advice on determining the stopping sight distance at ERAsand further advice on the width dimension and implementation on gradients.


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Section 10.17 revised guidance on lighting

Section 10.18 revised guidance on MIDAS loops.

Section 10.19 new advice on Road Restraint System.

Section 10.20 new advice on the treatment of maintenance and other similar

accesses.

Section 10.21 new advice on Maintenance Hardstandings

Appendix B: Glossary amended

Appendix C: Replacement of original contents with Environmental Assessment

checklists.

Appendix D Revised Generic Drawings showing the following changes:

o Drawings PR/99/09/001-012 designated Standard. Generalamendments.

o Amendment to width of white line used at back of hard shoulder leading to

changes in the carriageway cross-section.

o Removal of note regarding LBS1 width and HGV proportions on

PR/99/09/001-004. Refer now to Section 10.7.

o Inclusion of an ERA at mixed sign and signal gantry on drawing

PR/99/09/010

o Location of Hard Shoulder Ends signs.

o The possible need for an additional gantry at long merges.

o Revised note regarding signs and signals on the diverge.

Appendix E Revised Drawings with Definition of Exit and Entry Datum points.


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Document Map

Section Contents Page

1. About thisDocument

1.1 Who is this Guidance For? 1-2

1.2 What Does the Guidance Cover? 1-2

1.3 This Guidance in Context 1-8

1.4 Further Support 1-8

2. Overview of MM-HSR

3. Factors

Influencing MM-HSR Installation

3.1 Introduction 3-13

3.2 Existing Physical Constraints and Infrastructure 3-13

3.3 Traffic Flow Characteristic 3-13

3.4 Entry and Exit to MM-HSR Scheme 3-15

3.5 Link Lengths 3-16

3.6 Topography 3-16

3.7 Future Developments and Programmed Schemes 3-16

3.8 Summary 3-17

4. Economic

Appraisal 4.1 Introduction 4-194.2 The TAME MM-HSR spreadsheet model 4-20

4.3 Other Economic Impact Assumptions for the effect of MM-HSR4-21

5. EnvironmentalAssessment


5.2 Need for an Environmental Assessment and Procedural Pathway

5-23

5.3 Business Case and Scheme Approval Process 5-25

5.4 Environmental Assessment Process 5-25

5.5 Environmental Design and Potential Generic Mitigation Strategies

5-32

5.6 Earthwork and Structures Design Philosophy

5.7 Drainage Design Philosophy 5-37

6. SafetyConsiderations


6.2 Project Safety Risk Management System (PSRM) 6-40

6.3 Generic MM-HSR Risk aAeas to be Managed 6-43

6.4 CDM 2007 6-50


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7. LegislativeRequirements


7.2 Outline Methodology for Introducing New Regulations 7-53

7.3 Timescales to Commence Drafting of Sis 7-55

8. Operations

8.1 Introduction 8-578.2 Terminology Lane Referencing on MM-HSR Schemes 8-58

8.3 MM-HSR Traffic Officer Service (TOS) Procedures 8-58

8.4 Operating Regimes 8-60

8.5 Entry and Exit Scheme Signing, Road Marking and Signalling 8-74

8.6 Maintenance 8-78

8.7 Access for Emergency Services 8-86

8.8 Operating Speed 8-87

8.9 RCC and Traffic Officer Considerations 8-87

8.10 Through Junction Hard Shoulder Running 8-89

8.11 Compliance/Enforcement 8-90

8.12 Ramp Metering 8-91

8.13 Driver Behaviour, Education and Publicity 8-92

8.14 Operational Development 8-92

8.15 Monitoring and Evaluation 8-93

9. Technology9.1 Site data 9-95

9.2 Transmission System 9-95

9.3 Control System 9-96

9.4 Power Issues 9-97

9.5 Combined Equipment Cabinets (CEC) 9-99

9.6 Emergency Roadside Telephones 9-100

9.7 Lane Specific AMIs 9-101

9.8 Achieving Compliance 9-102

9.9 Post Mounted AMIs 9-102

9.10 Message Signs 9-102

9.11 Ambient Light Monitors 9-104

9.12 MIDAS 9-104

9.13 Hard Shoulder Monitoring 9-104

9.14 ERA Detection and Monitoring 9-105

9.15 CCTV General Surveillance 9-106

9.16 Ramp Metering 9-107

9.17 Commissioning of Equipment 9-108


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10.Infrastructure10.1 Piers, Parapets and Gantries 10-111

10.2 Clearance and Headroom 10-112

10.33 Railway Infrastructure Considerations 10-112

10.4 Alignment 10-113

10.5 Permanent Traffic Signs 10-114

10.6 Drainage 10-120

10.7 Lane Widths 10-120

10.8 Road Markings and Studs 10-121

10.9 Carriageway 10-123

10.10 Signal Gantry Frequency 10-123

10.11 Gantries in the Vicinity of Junctions 10-124

10.12 Gantries Design Considerations 10-128

10.13 Emergency Refuge Areas 10-129

10.14 Central Reserve 10-133

10.15 Stopping Sight Distances 10-133

10.16 Enforcement 10-134

10.17 Lighting 10-134

10.18 MIDAS Loops 10-136

10.19 Road Restraint System 10-140

10.20 Other Accesses 10-140

10.21 Maintenance Hardstandings 10-140

A References A-142

B Glossary of Terms and Abbreviations B-143

C Environmental Reporting Methodology Checklist C-145

D Drawings D-153

E Datum Point Definitions E-166

Appendices

F Index F-170


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1 Document Map - Section 1

Section


Contents Page

1.1 Who is this Guidance For? 1-2

1.2 What Does the Guidance Cover? 1-2

1.3 This Guidance in Context 1-8

1.4 Further Support 1-8

Key Points

Guidance is for Project Managers/Sponsors planning to implement MM-HSR with controlled use of Hard Shoulder

Scope of guidance is defined

Sets out assumptions used in the document

Provides a road map to installation

Explains need to remain up-to-date with MM-HSR developments


3. FactorsInfluencing MM-HSR Installation

4. EconomicAppraisal




8. Operations

9. Technology

10. Infrastructure


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1 About this Document

1.1 Who is this Guidance For?

This document provides guidance for delivery teams on the implementation of a Managed

Motorway scheme incorporating Hard Shoulder Running (HSR). It also provides guidance for

operational teams on implementation and subsequent management of the network.

It has been designed to provide the reader with information in a number of project areas (see

Section 1.2). Each of these is addressed in a distinct section some of which may be relevant

to all readers, whilst only one or two may be relevant to others. It has been designed as a

reference document and is not designed to be read in its entirety, but rather to help guide a

reader on specific issues.

A glossary of terms and abbreviations is presented in Appendix B.

An index is presented in Appendix F.

1.2 What Does the Guidance Cover?

1.2.1 Objective

Managed Motorways is a tool-box which facilitates the dynamic control of traffic for

congestion and incident management. The tools allow the road space to be managed in

different ways for varying conditions to maximise capacity whilst providing a safe and

informed environment for the travelling public and on-road resources (Emergency Services,Maintenance Operatives, Recovery Operators and Traffic Officers). The tool-box includes:

Hard Shoulder Running: Controlled use of the Hard Shoulder during times of heavy

congestion or during incident management

Controlled Motorways: The dynamic management of traffic in the designated running

lanes using Variable Mandatory Speed Limits (VMSL)

Queue Protection: Automatic protection of incidents and queues

Lane Specific Signalling: Protection of incidents and on-road resources

Ramp Metering: Controlling traffic entering the main carriageway from slip-roads or

connector roads to maintain the flow on the main carriageway

Integrated Traffic Management: Management of traffic on the motorway and local

road network

The objective of this document is to provide generic guidance on the implementation of

Managed Motorways incorporating Hard Shoulder Running (i.e. incorporating the

operational regime of controlled use of the Hard Shoulder). It does not provide guidance on

the implementation of the other items in the Managed Motorways tool-box. These arecovered separately.


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It is expected that the information presented in this document will be used in conjunction with

existing standards to enable the design of appropriate schemes.

Following consultation within the Highways Agency, the below has been agreed:

Within this document certain items have been highlighted by the Highways Agency as

requiring a submission of a Departure from Standard (i.e. A Departure from Standard

submission is required for X....). This does not mean that they are the only the items

requiring a departure. The purpose of this is to emphasise the need for a departure for the

item identified.

Each scheme needs to be individually designed taking into account local conditions. This

also means that new schemes could be more innovative than those which currently exist or

are being planned. In these circumstances advice from Highways Agency NetServ

([email protected]) should be sought.

Mandatory sections of this document, i.e. those that are a requirement of Managed

Motorways, are contained in Black Boxes. These requirements must be complied with or

obtain a prior agreement to a Departure from Standard must be obtained from the

Overseeing Organisation. The text outside boxes contains advice and explanation, which is

commended to users for consideration.

This document must be used forthwith on all Managed Motorway schemes currently being

prepared provided that, in the opinion of the Overseeing Organisation, this would not result in

significant additional expense or delay progress (in which case the decision must be recorded

in accordance with the procedure required by the Overseeing Organisation).

In exceptional situations, the Overseeing Organisation may be prepared to agree to a

Departure from Standard where the Standard, including permitted relaxations, is not

realisticallyachievable. If a Departure from Standard is required this course of action must be

discussed with the Overseeing Organisation at an early stage in the design process.

Proposals to adopt Departures from Standard must be submitted to the Overseeing

Organisation and formal approval received before incorporation into a design layout.

In difficult circumstances, Relaxations may be introduced at the discretion of the Design

Organisation, having regard to all relevant local factors, but only where specifically permitted

by this Standard. Careful consideration must be given to layout options incorporating

Relaxations, having weighed the benefits and any potential disbenefits. Particular attention

must be given to the safety aspects (including operation, maintenance, construction and

demolition) and the environmental and monetary benefits/disbenefits that would result from

the use of Relaxations. The consideration process must be recorded. The preferred option

must be compared against options that would meet full standards.


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The clauses within a Black Box do not require a Departure from Standard (unless this is

explicitly stated within the Black Box). However, this does not mean that the clauses within

the Black Box can be applied to a scheme without due consideration of their potential impact

on safety. For example, this document does permit lane widths that are different to those

stated in the DMRB. Application of these lane widths may affect the risk associated with

certain scheme hazards. For this reason an appropriate level of project review is required.The results of this review must be recorded and appended to the Hazard Log.

1.2.2 Revised process for Dealing with potential Departures from Standard issueson Early Delivery Managed Motorway schemes

The absence of a complete set of standards for Managed Motorways means that there is the

potential for a large number of Departures from Standard to be generated. In order to

manage this, a revised process is to be used as outlined below. Further details can be

obtained from the HA NetServ Group Manager, Road Safety & Casualty Reduction.

The use of those sections in this guidance that have been black boxed do not constitute

Departures from Standards, where compliance can be achieved. However, designers must

properly consider the appropriateness of the application of these sections of the guidance in

the Safety Report(s) and Hazard Log (See Section 6.2). In instances where compliance with

these black boxed sections cannot be achieved, or raise significant (Type C) safety issues,

the justification of the relevant design issues shall be disaggregated into discrete Departures

submissions or within a composite departures report submission. The HA NetServ Group

Manager Road Safety & Casualty Reduction will direct designers on any specific

requirements in this regard.

Where specific Departures are required, as stipulated in this IAN, the established processes

for the submission and approval of Departures shall be used. These Departures shall also be

properly considered in the development of the Safety Report and Hazard Log, including any

interrelation with those of those sections in this IAN that have been black boxed.

The Black Box items adopted by the scheme must be recorded in a Design Features report

that is appended to the Hazard Log. This must be reviewed and evidence recorded that

cumulatively these will not prevent the Safety Objective for the scheme being achieved.

Particular attention needs to be paid to the potential interaction of different features.


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1.2.3 Scope and Assumptions

The scope of this guidance is limited to the implementation of Managed Motorways

incorporating Hard Shoulder Running on motorways in England. (For brevity, this is

referred to as MM-HSR in the remainder of this document). Careful consideration is required

before MM-HSR is implemented in a new location on the motorway network. MM-HSR leadsto substantial changes in operational practices, implementation of technology and changes to

infrastructure. The complexity of design and operational requirements associated with MM-

HSR is difficult to comprehensively address in a single document. Therefore, the intention of

this document is to provide generic guidance on the main issues that need to be considered,

capturing lessons learned from the M42 Active Traffic Management (ATM) Pilot scheme

between Junction 3A and 7. It provides a baseline for future schemes which delivery teams

should further refine and value manage where safe and practicable to do so.

The following assumptions are made in this document:

The introduction of MM-HSR on a length of carriageway does not include the bringingforward of major maintenance schemes unless directed by the Overseeing

Organisation.

Where current structures or features (e.g. restraint systems, drainage) are fit for

purpose, they should not be replaced for the sole purpose of meeting current

standards. Other improvements should only be considered if what is there now is not

appropriate (for example, either unsafe or beyond economic repair). The asset

management decision making process therefore follows a logical process:

1. The true condition of the asset is established to determine if it is fit for

purpose.

2. If the asset is deemed fit for purpose, then it is reasonable for it to be retained.

3. If it is deemed not fit for purpose then there is another decision about removal

or replacement. This decision should be taken in the normal way to justify

renewal/upgrading including referring to the relevant Assessment Standards.

See Section 10 for further information.

This Guidance is based on the Design Manual for Roads and Bridges (DMRB) and

draws on the lessons learnt from the M42 Active Traffic Management (ATM) Pilotbetween J3A and 7 and M25 (Controlled Motorways).

MM-HSR is currently only implemented on existing dual 3-lane motorways with

standard width Hard Shoulder (D3M).

For installation on other motorways configurations, such as D4M and D5M, further

advice must be sought from, Highways Agency NetServ

([email protected]) early in the option assessment phase.


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Controlled use of the Hard Shoulder applied only to links1 between junctions. If a

scheme incorporates controlled use of the Hard Shoulder within a junction then

designers should be aware that separate guidance on Through Junction Running is

available [1].

It is assumed that after scheme handover the MM-HSR will be managed by NetworkOperations (NO) operated from an existing Regional Control Centre.

1A motorway link is defined as the carriageway between two adjacent junctions.


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1.2.4 Document guide

Figure 1-1 shows how the information contained in this guidance document would support

the implementation of an MM-HSR scheme. The numbers for each box represent the

relevant section of this document.

Figure 1-1: Implementation of a MM-HSR scheme

Figure 1-1 shows a generic sequence of events. However, this may not be appropriate for

every scheme. Feedback would be expected from all aspects of the scheme, including how it

operates both in terms of traffic management and maintenance activities.

The way the scheme will operate determines whether any operational modifications are

required and also provides key data for the traffic, environmental and economicassessments. The operational requirements will also determine the technology and

infrastructure requirements.

Experience gained from the implementation of MM-HSR schemes is expected to feed into

further Highways Agency advice, guidance or standards. Project Managers/Sponsors should

ensure that relevant information is fed back to Highways Agency NetServ

([email protected]) so that it can be incorporated into future updates.

8. Operations

Scheme Inception

3. Factors Influencing

Installation

4. Economic

Appraisal

5. Environmental

Assessment

7. LegalRequirements

9. Technology

10. Infrastructure

6. Safety

Assessment

11. Stakeholder

Management

Scheme Delivery

Feedback to HA NetServ

Updated

Guidance

Scheme designers must consider as early as possible how the scheme will operate and how

it will be maintained taking into account local factors.


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Section


2. Overview of

Key Points

Provides a description of what MM-HSR is and how it works

Details of the benefits and results

How the MM-HSR is managed






8. Operations

9. Technology

10. Infrastructure


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2 Overview of MM-HSR

Managed Motorways, incorporating the controlled use of the Hard Shoulder as a running

lane (MM-HSR) during periods of high vehicle flow or incidents, is recognised as an

increasingly important tool in managing the motorway network. It provides a number ofbenefits compared to conventional road-widening; including cost effectiveness, speed of

construction and an increased likelihood of implementation within the existing highway

boundary.

Figure 2-1: MM-HSR as implemented on the M42 ATM Pilo t

MM-HSR provides an additional lane during congested periods by utilising the existing Hard

Shoulder as a running lane. This concept has been piloted on the M42 ATM scheme (J3A

J7) in the West Midlands2 (Figure 2-1) and early indications [2] show that this is a safe,

efficient and sustainable way of creating increased capacity within the existing road space to

manage changing traffic conditions.

MM-HSR applies the latest proven technology3in new ways to enable controlled use of the

Hard Shoulder, whether the congestion is caused by peak traffic flows, an incident, or a

special event. The following paragraphs provide a high level summary of MM-HSR operation.

2Useful information on the M42 ATM Pilot scheme (J3A J7) is available at http://www.highways.gov.uk/atm

3Note: the most up-to-date generation of signals and signs was used on the M42 ATM Pilot Scheme. While theunderlying scheme technology remains standard, innovative applications of this technology have been used tomeet the scheme objectives.


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During periods of low traffic flow and when no incidents are present, no signs or signals are

displayed. As traffic flow increases, a variable mandatory speed limit (VMSL) is automatically

displayed by the Advanced Motorway Indicators (AMI) above the running lanes (similar to

those seen on the M25 Controlled Motorways scheme). However, unlike the M25 Controlled

Motorways, an additional AMI displays a Red-Cross lane control aspect over the Hard

Shoulder (See Section 8.4.2). When traffic flows require additional capacity, and when it issafe to do so, the Hard Shoulder is opened to traffic by the Regional Control Centre (RCC)

operators. This is conveyed to road users through the display of a mandatory speed limit

above the Hard Shoulder, in addition to those displayed over the remaining running lanes,

and appropriate text messages are shown on the Message Signs Mark 4 (MS4s).

When the demand level subsides, the Hard Shoulder is closed to traffic by the RCC

operators and the motorway reverts to an M25 Controlled Motorway style environment with

mandatory speed limits displayed on the AMIs above the running lanes and a Red-Cross

lane control aspect displayed above the Hard Shoulder. As traffic flows further reduce, the

signs and signals are switched off and the carriageway returns to conventional motorway

operation.

To manage the MM-HSR environment and the process for opening and closing the Hard

Shoulder, signals and message signs are mounted on gantries. Emergency Refuge Areas

(ERAs) are provided at appropriate regular intervals, generally co-located downstream of the

gantry where the topography and road layout permits. Over each lane, an AMI displays

VMSL and lane control aspects. Each gantry is equipped with an MS4 to provide driver

information and reinforce the display set on the AMIs. Good compliance to the VMSL is

supported by the use of an appropriate enforcement system (in the case of the M42 Pilot the

Highways Agency Digital Enforcement Camera System (HADECS) is used).

A system of in-road detectors (in the case of the M42 Pilot, Motorway Incident Detection and

Automatic Signalling (MIDAS) loops) is used to monitor traffic speeds, flows and queues.

Comprehensive Closed Circuit Television (CCTV) coverage is provided to allow the control

room operators to monitor the road network and rapidly detect and resolve incidents.

A hard shoulder detection system (in the case of the M42 Pilot, fixed CCTV) is used to

support the RCC Operator in implementing the hard shoulder opening sequence.

Each MM-HSR requires a unique set of operational procedures to manage the scheme.

Effective training and adherence to these procedures is fundamental to successful operation.


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3 Factors inf luencing MM-HSR installation

3.1 Introduction

It is important that assessment of the following factors is undertaken prior to determining the

feasibility and economic viability of implementing MM-HSR at a particular location on the

motorway network. Although MM-HSR is a very flexible solution, there may be locations

where another solution, for example Conventional Widening and/or Controlled Motorways,

may be more appropriate.

3.2 Existing Physical Constraints and Infrastructure

In considering MM-HSR, it is necessary to establish the extent of existing physical

constraints particularly in relation to infrastructure. This assessment should not only

consider horizontal constraints (reduced width Hard Shoulder, Hard Shoulder discontinuities

at overbridges etc) but also vertical constraints (vertical clearances over the Hard Shoulder

may not be the same as those over the running lanes). It is necessary to identify the location

of cuttings and embankments as these may influence the locations for ERAs. The integrity of

the existing Hard Shoulder also needs to be considered (see Section 10.9) as well as thetype and location of existing drainage (see Section 10.6) and the presence or otherwise of

lighting (see Section 10.17).

Where controlled use of the Hard Shoulder running through the junction is to be considered

(whether at implementation or at some point in the future), then assessments to check

whether or not this can be physically achieved need to be undertaken. If it can only be

achieved by removing or widening structures etc, these costs need to be included in the

economic assessment for the scheme (See Section 4). Removing or widening structures is

likely to have a significant impact on the programme.

3.3 Traffic Flow Characteristics

Local and strategic traffic flow characteristics need to be fully understood when determining

where to implement MM-HSR. This information should help designers to understand the:

Traffic flow suitability for an MM-HSR solution

Period of Operation over the design life of the scheme

Geographic extent of MM-HSR on a scheme

Need for through junction hard shoulder running

In investigating the various factors involved, designers must decide how the scheme is

expected to operate and be maintained (See Section 8). Without this understanding, the full

implications of each factor cannot be assessed.


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Effect of future traffic flows

3.3.1 Traffic flow suitability for an MM-HSR solut ion

MM-HSR is primarily designed as a tool to alleviate congestion. However, MM-HSR offers a

flexible solution and different modes of operation can be applied to differing circumstances

(for example as a tool to mitigate the risk of incidents).

Evidence from the M42 ATM Pilot between J3A and 7 suggests a 7% to 9% improvement on

through put verses 3 Lane (3L) VMSL. In calculating the likely capacity for future schemes a

number of factors should be taken into account these include:

Distance between junctions - weaving movements may affect capacity.

Proportion of commuters a high proportion of commuters may lead to a higher

capacity as a great proportion of drivers are used to travelling through the scheme.

Geometry a tight geometry may reduce capacity.

Proportion of HGVs a high proportion may reduce capacity.

Through Junction Hard Shoulder Running leading to improved capacity through

junctions where there is a high proportion of through traffic.

Environment weather conditions.

3.3.2 Period of Operation

This section only considers the opening of the Hard Shoulder for congestion management.

The Hard Shoulder can be opened at times when it is predicted that traffic flow is going to

exceed the natural capacity of the motorway. The Hard Shoulder is likely to be opened

during the morning and evening peak. However, there is no reason why the Hard Shoulder

cannot be opened for the morning peak and closed after the evening peak, if flow demands

it.

For any new MM-HSR scheme detailed analysis of traffic flows is required to determine flow

thresholds for informing RCC operators of when to open and close the hard shoulder, as wellas for Controlled Motorway settings. These flow thresholds will depend on a number of

factors including topographical gradient and flow composition (e.g. proportion of HGVs).

Determining the likely frequency and duration of hard shoulder usage will help determine

resource levels required for opening and closing the hard shoulder. During these periods

VMSL will be applied and the effect on maintenance activities must therefore be considered.


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3.3.3 Geographic extent of MM-HSR on a scheme

Traffic modelling work should be used to determine the links that are likely to require Hard

Shoulder usage. For example, traffic patterns of through traffic and local traffic may mean

that the Hard Shoulder need not be opened for each peak period on all links. Equally some

links may need to be opened for the morning and evening peaks, whilst others may need tobe left open throughout the inter-peak.

As each link has different characteristics, modelling may reveal that one or more links in the

centre of a scheme do not require MM-HSR. However, if this is the case, it needs to be

determined how the scheme would physically look to road users, and how it would operate

with a mixture of MM-HSR and non-MM-HSR links. It may be deemed necessary to

implement MM-HSR on links where congestion is not the key driver, but where scheme

consistency becomes important. Different Operational Regimes (ORs) may be appropriate in

these circumstances, possibly without the regular use of the Hard Shoulder as a congestion

management regime.

3.3.4 Need for through junct ion hard shoulder running

The traffic flow joining and leaving at each junction within the scheme as this determines

whether or not Hard Shoulder running is required through the junction (see separate

guidance IAN112/08 Managed Motorways Implementation Guidance Through Junction

Hard Shoulder Running [1] Section 3.1). If the traffic flow on the main carriageway remains

high through the junction (i.e. the efficient operation of the junction is impeded by the forecast

level of flow through the existing junction configuration) then a Through Junction Running

type arrangement may be required.

3.3.5 Effect of future traffic flows

It is also important to consider current and future predicted traffic growth levels and their

effect on the local and strategic network. MM-HSR suits locations where the inter-peak flows

(either during the day or night or both) are mostly within the existing capacity of the motorway

and are expected to remain this way for the period covered by the Economic Appraisal

spreadsheet model (See Section 4). Conventional widening may be a more appropriate

alternative where capacity is reached during the inter peak period.

3.4 Entry and Exit to MM-HSR Scheme

It is important that drivers understand when they are either entering or leaving an MM-HSR

scheme. On the main carriageway this is best achieved on the main carriageway by starting

and terminating controlled use of the Hard Shoulder at junctions (see Section 8.5) However,

with careful planning, it is possible to commence and terminate MM-HSR at an interchange,

as achieved on the M42 ATM Pilot at Junction 3A. Entry to or exit from the MM-HSR scheme

may also be to or from a Controlled Motorway link.


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3.5 Link Lengths

For the successful operation of MM-HSR it is important to establish:

Whether it is physically possible to install the necessary signals and signing to convey

clear and unambiguous information to road users about the status of the HardShoulder. For very short link lengths, advice should be sought from Highways Agency

NetServ ([email protected]).

Whether appropriate weaving lengths can be achieved.

That each link can be opened in a timely manner.

The current way that the Hard Shoulder is opened to traffic requires sections4

between signal gantries to be opened in sequence (following confirmation that the

Hard Shoulder is clear of obstruction See Section 8.4.3). This sequence takes a

finite length of time to complete, which in simple terms means that the longer the link,the longer it takes to open. If the scheme has a number of longer links it may be

necessary to develop a revised procedure of opening and closing the Hard Shoulder

and this may in turn have an impact on resource requirements. For example, one

possibility is opening the complete length of the Hard Shoulder on the link, as a single

unit, at the same time. However, to do this it is necessary to put in place a process for

checking that the entire length of the Hard Shoulder is clear of stopped vehicles

and/or debris. There needs to be minimal delay between this check and the opening

of the Hard Shoulder and it may be that a revised methodology is required to achieve

this.

3.6 Topography

During Hard Shoulder Running or Controlled Motorways, MM-HSR relies on signals and

message signs to convey the status of the Hard Shoulder to road users. It therefore follows

that drivers need to have a clear view of these signals and signs.

On motorways with topographical constraints, it may be challenging to convey information

clearly to the driver. The topography may make ERA installation challenging and expensive.

Vertical alignment may also restrict where ERAs can be located. Steep inclines on the

carriageway could require additional ERAs as broken-down vehicles may not be able to

travel as far. Such considerations may significantly increase the anticipated cost of MM-HSRimplementation.

3.7 Future Developments and Programmed Schemes

It is important to establish the status of any pending developments and schemes that may

affect the network (in the scheme location) at some point in the future, for example major

maintenance schemes, junction improvement schemes and other local developments with

planning permission.

4A section is the length of carriageway between adjacent signal gantries.


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Section





Contents


4.2 The TAME MM-HSR spreadsheet model 4-204.3 Other Economic Impact Assumptions for the Effect of MM-HSR

4-21

Key Points

The process that will be used for the economic appraisal of an MM-HSRscheme.

Description of the TAME MM-HSR spreadsheet model

MM-HSR Spreadsheet Model Assumptions/ Considerations

Explains why an INCA assessment should be carried out for both MM-HSR and full widening.




8. Operations

9. Technology

10. Infrastructure


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4 Economic Appraisal

4.1 Introduction

The information presented in this section complements the existing processes for the

economic appraisal of Highways Agency schemes.

The process that should be used for the economic appraisal of an MM-HSR scheme has

been developed by the HA Traffic Appraisal Modelling and Economics (TAME) group.

The process involves:

Using a spreadsheet model (See Section 4.2) to determine the economic effects (link

transit, queuing and merge delays and vehicle operating costs) of introducing an MM-

HSR scheme on the Highways Agency network.

Currently the spreadsheet is used to carry out a two stage assessment of MM-HSR:

An initial Stage 1 assessment uses the benefits generated by the spreadsheet in

conjunction with construction and associated costs to ascertain whether MM-HSR is a

viable option. A Stage 1 assessment can include, if available, the other elements of

economic appraisal such as the effects of accidents, maintenance etc.

If the Stage 1 assessment indicates that MM-HSR is a viable option, a Stage 2

assessment can then be carried out using TUBA outputs based on data from a

scheme traffic model to derive the full network wide affects of MM-HSR. The Stage 2assessment includes the other elements of economic appraisal including the effects

of accidents, maintenance etc.

A guidance document on the process and use of the spreadsheet is available from the TAME

group. It covers:

MM-HSR spreadsheet model assumptions

Other economic impact assumptions for the effect of MM-HSR

The spreadsheet methodologies for the Stage 1 and Stage 2 assessments

Pro-formas for the Stage 1 and Stage 2 assessments

Pro-forma for the treatment of consecutive links


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4.2 The TAME MM-HSR Spreadsheet Model

The TAME MM-HSR spreadsheet model uses various inputs to enable the comparison of

four scenarios:

Existing lane configuration Do-Minimum5,

Do Minimum + MM-HSR operating with a maximum speed limit of 50mph when the

Hard Shoulder is open to traffic6

Do Minimum + MM-HSR operating with a maximum speed limit of 60mph when the

Hard Shoulder is open to traffic

Full Widening

As noted above, the outputs from the spreadsheet are link transit, queuing and merge delaysand Vehicle Operating Costs. A number of assumptions/considerations associated with the

spreadsheet are noted below.

4.2.1 MM-HSR Spreadsheet Model Assumptions/ Considerations

The spreadsheet does not assess the safety benefits or the economic effects of MM-HSR on

the wider network beyond the motorway.

The spreadsheet does not provide data on scheme costs. Scheme costs, calculated in terms

of Present Value Costs, will need to be derived outside the spreadsheet.

As noted previously, the spreadsheet has been set up to appraise both a 50mph and 60 mph

speed limit operation for MM-HSR (see Section 8.8). The traffic flow input to each scenario

should be the same and, for a Stage 2 Assessment, should include the effects of variable

demand responses for future year flows derived from the macro traffic assignment/demand

model. When undertaking a Stage 1 Assessment without the benefit of variable demand

based forecasts, care should be taken to ensure that the forecast flows do not exceed the

available capacity in both the Do-Minimum and Do-Something scenarios. (The Stage 1

method assumes the same flows for both Do-Minimum and Do-Something. This is likely to

lead to flows greater than the Do-Minimum capacity and hence the occurrence of queuing

delays.)

The full widening scenario and MM-HSR options do not take account of the implementation

of VMSL.

5This is D3M with the fitment of automatic queue protection

6See Section 8.8 regarding operating speed


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4.3 Other Economic Impact Assumptions for the Effect of MM-HSR

An INCAassessment should be carried out for both MM-HSR and full widening to assess the

effects on journey time reliability.

It should be assumed that introducing MM-HSR is expected to lead to a 15% reduction in

accidents compared with the implementation of automatic queue protection on its own. This

is based on the reductions achieved as a result of Controlled Motorways (VMSL) on the M25,

as longer term data from MM-HSR solutions is not yet available. This assumption is also

applicable to the full widening option if it also includes VMSL, and should be updated when

longer term validated MM-HSR accident data is compiled.

A full QUADRO assessment will be required to determine costs associated with the planned

replacement of MM-HSR equipment.

Operational costs associated with MM-HSR should also be included in the scheme costsover the projected life of the scheme including any increased staff costs (e.g. traffic officers/

control room operators).


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Section






Contents Page



5-23

5.3 Business Case and Scheme Approval Process 5-25

5.4 Environmental Assessment Process 5-25

5.5 Environmental Assessment and Potential Generic Mitigation Strategies

5-32


5.7 Drainage Design Philosophy 5-37

Key Points

Description of the Environmental Assessment methodology

The topic areas to be addressed and the anticipated outcomes of anenvironmental assessment process, based on currently available dataand experience of previous and ongoing projects

Potential environmental impacts arising from the implementation of anMM-HSR scheme

Potential mitigation strategies to avoid, minimise or offset any adverseimpacts

Earthworks and Drainage design philosophies



8. Operations

9. Technology

10. Infrastructure


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5 Environmental Issues

5.1 Introduction

This section presents a summary of key environmental considerations associated with the

implementation of MM-HSR at a new location on existing sections of the motorway network

and includes:

A potential scheme environmental assessment procedural progression path

An initial generic Scoping exercise to identify specific topic areas of relevance toMM-HSR schemes

Potential environmental impacts arising from the implementation of an MM-HSRscheme

Potential mitigation strategies to avoid, minimise or offset any adverse impacts

A summary of anticipated outcomes of an environmental assessment process, basedon currently available data and experience of previous and ongoing projects.


MM-HSR requires changes to existing infrastructure (additional gantries, ERAs etc) and

therefore is likely to be delivered via some type of improvement scheme. Improvement

schemes are subject to compliance with the Highways (Assessment of Environmental

Effects) Regulations 1999 as amended. Therefore, to comply with the regulations despite

generally being located entirely within the existing HA land boundary, an MM-HSR scheme

requires an appropriate level of environmental assessment as set out in the Agencys current

guidance HA200/08, HD 47/08 and HD48/08. For advice on any environmental assessment

or design issues contact the Highways Agencys NetServ Regional Environmental Advisors

(REA) who can be contacted through [email protected].

5.2.1 Screening

The guidance in HD47/08 sets out the pathway (known as screening) for establishing the

appropriate level of Environmental Assessment for each project;

1. The first step is to decide if the project is an Annex I or Annex II project (see Figure

5-1). Thresholds for Annex I and Annex II projects are included in HD 47/08 Section

1.7. Previous experience has shown MM-HSR schemes generally follow the Annex II

pathway as a result of the scale of the intervention and construction works.

Each individual scheme must be assessed on its own merits, taking into consideration any

specific scheme and or local environmental requirements.


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2. The second step is to decide if the project is a relevant project. Again HD 47/08

Section 1.8 includes the thresholds with respect to size and sensitivity which help to

determine whether the project is a relevant project. Again previous experience has

suggested MM-HSR schemes are likely to be relevant projects.

3. The third step is to arrive at a determination of the project. This means that anenvironment assessment needs to be undertaken which will allow a determination to

be made. This is then summarised in a Record of Determination (ROD) which is

prepared by the project team and sent to HA NetServ who approve the Record of

Determination (RoD) on behalf of the Secretary of State (SoS). This then gives the

project team the authority to publish the Notice of Determination in the London

Gazette and at least one other local paper (local to the scheme) for a minimum period

of six weeks. This then allows 6 weeks to object to the determination, in which time

no decisions should be taken on project development which may prejudice the SoSs

position. Projects should note that it is intended to issue new guidance on

determination shortly and projects should consult with their NetServ Regional

Environmental Advisors (REAs) for clarification.

This procedural pathway has been utilised on previous and ongoing schemes including the

M42 ATM Pilot between J3A and 7, the ongoing Productivity TIF Birmingham Box Managed

Motorway Phase 1 and 2 (BBMM 1&2) scheme. Both have both resulted in a determination

which has concluded that no formal Environmental Impact Assessment and Environmental

Statement were required. This has been documented as a defensible, pragmatic mechanism

for early delivery of what are, primarily technology based projects. However it should be

pointed out that each project inhabits its own specific geographical context, with differing

constraints. Therefore each determination should take into account local circumstances. As

Determination is a significant procedural and gateway process for projects, the NetServ

REAs should be consulted throughout the process.

Figure 5-1, abstracted from HA 47/08, summarises the screening process for the progression

of any scheme.

It is considered likely that based on experience to date the RoDs for MM-HSR projects would

establish that a formal Environmental Impact Assessment (EIA) would not be required

including the production of an Environmental Statement. However this must be reviewed on a

scheme by scheme basis.


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Figure 5-1: HA Determination Process

5.3 Business Case and Scheme Approval Process

Environmental information in the form of the Environmental Appraisal Report (EAR), obtained

in support of the determination assists the schemes progress through the project approval

stages.

5.4 Environmental Assessment Process

Generally the undertaking of an environmental assessment process, and subsequent

production of an EAR, or Environmental Statement, for an MM-HSR scheme on an existing,

operational highway corridor should recognise that:


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To a degree design choices may be constrained by operational necessity; if this is

the case and the design is fixed early, the EAR could move straight to the

appropriate level of assessment (see HA 200/08) relatively quickly followed by a

determination process.

In the context of an operational highway corridor there are probably already existingimpacts upon locally sensitive receptors. The project assessment should only

include those impacts attributed to the project including any cumulative impacts. As

such assessments may reasonably conclude the impact is a relatively small addition

to the baseline.

5.4.1 Scoping of Likely Impacts

In accordance with HA 204/08 the first level of environmental assessment is scoping. From

the experience on the M42 ATM Pilot and the productivity TIF Birmingham Box Managed

Motorway Phase 1 and 2 scheme, a generic scoping exercise would suggest the followingtopic areas including their likely impacts are likely to be the main areas to assess and report

on.

Ai r Quality: Air Quality is likely to be in scope for most projects due to the potentialimpacts (both positive and negative) on any nearby Air Quality Management Areas

and consideration against the Air Quality Strategy Objectives/EU Limit Values. The

M42 ATM Pilot between J3A and 7 experience using evidence based assumptions

demonstrated that the operation of the schemes may result in some minor beneficial

reduction in specific emissions via the ability to control and regulate traffic speeds and

it may be important to demonstrate this. Projects should ensure that the scope of any

air quality assessments is appropriate to the circumstances of the scheme andsufficient to clarify the impacts, both positive and negative and if necessary compare

the results against the pollutant concentrations as defined by the UK Air Quality

Strategy Objectives and EU limit Values.

The current assessment guidance on air quality is contained in HA 207/07 DMRB

Volume 11 Section 3 Part 1.

There may be air quality issues associated with the construction phase. However it is

likely with best practice these can be contained with legal limits and are temporary.

Cultural Heritage for most schemes, scoping exercises will identify that MM-HSRprojects almost certainly are contained within disturbed highway boundary, therefore

impacts on buried archaeology are considered to be unlikely and scope out any

further assessment. Any potential impacts are likely to be limited to receptors off site,

such as the effects on the setting of any adjacent listed building. Scheduled Ancient

Monument. or conservation area, or historic landscapes and if this is likely then this

aspect would be scoped in and further assessment undertaken.

The guidance on cultural heritage assessment is given in DMRB HA 208/07.


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Disruption due to Construction - No significant long term impacts can beanticipated arising from the construction and installation process, any impacts being

temporary in duration and reversible. Any potential impacts would be controlled and

managed in accordance with procedures set out in a Construction Environmental

Management Plan (CEMP). The construction process associated with MMHSR

schemes requires a Site Waste Management Plan (SWMP) to be produced,particularly when older structures such as gantries may be removed or refurbished,

which may contain controlled materials such as asbestos which requires detailed

assessment and appropriate handling in line with best practice health and safety

guidance and legislation. Projects should note it is intended to issue guidance on

SWMP shortly.

Ecology and Nature Conservation This is a subject which is likely to in scope dueto the fact that MM-HSR projects have the potential to generate the following type of

impacts in relation to ecology and nature conservation. The following is a list of

potential impacts:

The physical land take (engineering works) required to construct the new

gantries and cabinets (including associated cabling), and the physical land take

requirements associated with ERAs, along with any structural engineering

works to support them, and any temporary areas of construction may have a

local effect on habitats or protected species.

Therefore there may be the potential for temporary exclusion or relocation of

protected species under appropriate licence conditions from Natural England

(NE) and or Department for Environment, Food and Rural Affairs (DEFRA).

Finding receptors sites in an reduced soft estate footprint may be an issue.

It can be anticipated that any impacts on habitats and protected species within the HA

boundary are likely to be considered as of local scale. This is not to say they may not

be locally significant. If data collection and or surveys identify actual or potential

presence of protected species, then discussions with the appropriate licensing

authority Natural England would have to be concluded to agree mitigation strategies.

If there are designations that lie within the highway corridor then consent maybe

needed from appropriate authorities.

Whilst it is considered, on the basis of available evidence to date, that it is unlikely

that the projects would have direct or indirect effects on off-site designations, eachproject should however take into consideration any potential for effect on adjacent

Sites of Special Scientific Interest (SSSIs) and specifically Special Protection Areas

(SPAs), Special Areas of Conservation (SACs). Project teams are reminded that

scoping exercises should consider the guidance contained in HD 44/09 on the

requirements for Assessment of the Implications on European Sites (AIES) with

reference to SPAs and SACs should be considered in the form of an initial screening

exercise, to discussed and agreed with the REA on behalf of the HA with a view to

advising on the requirements for an Appropriate Assessments.

The current guidance on ecology and nature conservation is contained in HD 44/09

and DMRB Vol 11 Section 3 Part 4.


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Landscape Effects This is a subject which is likely to in scope. For MM-HSRschemes the primary impacts anticipated can be split into two key areas: Visual

Effects and Landscape Character Effects. The following provides an indicative list of

potential impacts that may require consideration:

Visual impacts

For visual effects the receptors will be people; those living or working near the

motorway, users of adjacent footpaths and recreational facilities and of lesser

importance road users. The following factors will affect the magnitude of visual

effects and need to be considered;

Views of the motorway resulting from the removal of existing landscape

planting to accommodate gantries, signs, associated buried cables and ERAs

together with the establishment of new sight lines.

Views of gantries, signs, CCTV masts and other new road furniture fromsensitive visual receptors in the motorway corridor.

Day and night time effects of lighting should be considered separately and the

possibility of light spillage to adjoining sensitive receptors should be taken

account of.

If used, the local impact associated with the height and density of verge

mounted CCTV masts and lighting columns.

The potential temporary loss or cutting back of areas of established tree and

shrub cover, to provide working space within the highway boundary, aroundstructures, along the cable corridors and or at any transverse crossing points;

The narrowing of existing landscape screening may cause an indirect effect as

the residual vegetation becomes un-sustainable and would have to be removed

as it would become un-maintainable.

Landscape Character Effects Key effects on landscape character are likely to

result from the following:

The introduction of new infrastructure such as gantries, signs, CCTV masts,

cabinets, access steps and other new road furniture may all contribute to achange of landscape character and have an urbanising effect. The position,

height, shape, density and massing arrangement of these features are all key

considerations.

The removal of existing vegetation which can change the pattern of the

landscape at the local level and affect the way the landscape is perceived.

It should be remembered that if there are several projects along a route, then

their effects together may in increase the sense of change in landscape

character via cumulative effects.


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The landscape assessment should focus on how the landscape character will

be changed and should take account of measures incorporated into the

scheme design to mitigate adverse effects. The effects of schemes within

designated landscapes such as National Parks and Areas of Outstanding

Natural Beauty are likely to be more significant and special design solutions

may be required.

It is currently anticipated that generally the impact of implementing MM-HSR on an

existing network is likely to generate overall impacts of neutral to slightly adverse overall.

This may however vary, particularly if the scheme requires significant new lighting

provision within sensitive and or designated landscape areas. Individual gantries and

other new features may also have a locally more significant adverse impact which may

be difficult or impossible to mitigate. Due to the site specific nature of impacts it is difficult

to generalise until investigation can be completed for an individual scheme.

The current assessment guidance for Landscape is contained in DMRB Vol 11 Section 3

Part 5

Traffic Noise and Vibration It is likely noise and vibration is a subject which will bescoped in for most projects.

Generally, adverse impacts are likely to be associated with the construction phase

which is temporary and can be controlled through the Construction Environmental

Management Plan (CEMP). Longer term MM-HSR running may provide some

potential for benefits derived from the ability to control and regulate traffic speeds and

movement patterns and it may be important to demonstrate this. This should be

addressed through appropriate monitoring, modelling and assessment as required.

It may be necessary to identify night-time noise impacts in situations where it is

expected that the MM-HSR scheme will be in operation during the night time hours

(11pm to 7am).

It may also be necessary to carry out an assessment to determine if any vibration

impacts are likely to result from an MM-HSR scheme. It is possible that increased

levels of ground-borne vibration are possible in situations where vehicles and HGVs

in particular, will be running both closer to properties and on an unimproved

hardshoulder.

On the basis of best available evidence to date, an overall assessment of neutral

impact may be expected for a majority of MM-HSR schemes.


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If the outcome of an assessment of an MM-HSR scheme fails to predict a neutral

impact then some mitigation may be required. Current policy precludes resurfacing

simply to reduce noise levels. However, if the current condition of the existing

surfacing justifies significant intervention, adopting quieter surfacing may be

considered. This would potentially demonstrate betterment to an assessment of

neutral from currently available data from the M42 ATM Pilot between Junctions 3Aand 7 and ongoing Birmingham Box schemes. It should however be noted that any

reduction benefit from quieter surfacing would be dependant upon several factors,

including whether or not the surfacing extends across all, or just individual

carriageways.

Projects should ensure that the scope of any noise assessments is appropriate to the

circumstances of the scheme and sufficient to predict the overall impact of traffic noise

of an MM-HSR project.

The current assessment guidance for Noise is set out in DMRB Vol 11 Section 3 Part

7. HA 213/08.

Effects on All Travellers It is not thought likely any scoping exercise wouldrecommend a detailed level of assessment, but projects may decide to scope this in.

It is also not thought likely there would be any significant impact on non motorised

users. There is clearly potential for a degree of urbanisation of the motorway corridor

as perceived by vehicle travellers and, particularly once accustomed to the MM-HSR

operational environment. Potential stress relief through improved lane discipline,

journey time reliability and improved traffic management at incidents. This has been

observed from the ongoing monitoring of M25 Controlled Motorway and the M42 ATM

Pilot. The relative impacts of these factors should be considered in the assessment.

For effects on Vehicle Travellers assessment guidance is provided by DMRB Vol 11

Section 3 Part 9

Water Quality and Drainage Assessment of water and drainage issues would

normally be expected to be scoped out as MM-HSR projects make no effective

change to the existing drainage asset and are not expected to have new significant

incursions into the water table / flood plains / or direct impact on rivers or other water

bodies. Any impacts are expected to be short term during the construction process.

Current available information and evidence based assumptions suggests that the

scale of the construction works associated with MM-HSR within existing highwayboundaries, would not have a significant detrimental impact upon the existing surface

or ground water environment. As such no assessment of discharge rates, water

quality and flood risk will normally be required. In some locations however the

following situations may arise;

1. Identified risks to the water environment from the existing asset;2. Known failures with the drainage system in the project area:3. The need for hardening of the central reservation and installation of High

Containment Concrete Barriers leading to potentially significant increases in thehardened area of the carriageway.


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Policies and Plans generally not applicable, not anticipated to directly impact onthe majority of Regional or Local Planning policies apart from assisting in wider

proposals to promote the economic development of the area. Relevant policies and

protected sites are identified to contribute to the assessment of relative sensitivity of

individual equipment site locations.

The above initial generic Scoping Exercise has been undertaken and agreed with HA

Network Services and is taken from the various environmental topic areas set out in the

DMRB. It should however be reiterated that, whilst drawing on these guidelines, each

individual scheme should undergo its own Scoping exercise. It is likely that for some projects

this generic list of subject would be amended/revised as appropriate to take into account

local context.

5.4.2 Reporting Methodology

The specific reporting methodology proposed for the environmental assessment process isbased on DMRB and should be utilised in conjunction with the requirements of the latest

HAs, HDs, IANs (HA 201/08, HD 48/08) in combination with the requirements of MPs MMP

Project Control Framework. To establish a consistency of data collection requirements,

record of consultation and audit trail, projects are advised to use the 3 checklists attached

(Appendix C). This methodology was utilised during the preparation of the EAR for the M42

ATM Pilot between Junctions 3A to 7 project and has been utilised for the ongoing

assessment of the Birmingham Box Productivity TIF Phase 1 and 2 scheme. This would

entail:

Existing Data Review - Utilising Checklist 1 (Appendix C) to collate data on astrategic overview and local scale and to map existing constraints and sensitivities to

MM-HSR. Information to be obtained from the HAs Maintaining Agents, the

Environmental Database (Environmental Information System - ENVIS), other ongoing

or completed HA projects, and published sources such as Local Planning Authority

(LPA) Local Development Frameworks.

Consultation Consultation, once authorised by the Project Manager/Sponsor,should be entered into with key statutory bodies such as Natural England and the

Environment Agency and other non-statutory parties which may hold information such

as the local Wildlife Trusts. This should take the form of a targeted Scoping and

consultation letter followed up by telephone consultation and re-issue of letters andmeetings as required. Initial Checklists and supporting Constraints Plans should then

be supplemented by additional/updated data from this consultation process.

Field Surveys and Environmental Modelling Once the scheme option and extentshave been identified more detailed site specific assessments should then be

undertaken as necessary, with the information collated in the following checklists.

Checklist 2 (Appendix C) to be populated with information on temporary construction

impacts, generally associated with the long linear lengths of cable upgrade, barrier

and CCTV corridors, and Checklist 3 (Appendix C) used to record field observations

for each major equipment site (specifically landscape, heritage and biodiversity) and

to identify mitigation measures.


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The above referenced Checklists would then be located in a support volume to the main

EAR text, where the key information will be presented in a summary form. Other

specialist reports, such as those summarised below would then also be lodged in

supporting volumes to the main EAR report. These may include:

Specialist ecological reports - Air and noise reports and any other supporting datautilised in the assessment process, should then be located in a further support

volume(s).

Projects are reminded of the need to consider potential for Cumulativeenvironmental impacts, mitigation strategies and any residual impacts, referencing

DMRB & IANS and WebTAG, which should then be presented in a Volume 1

Environmental Assessment Report/ES which should act as the main reference

document.

This process has been successfully used on past and ongoing projects, including the M42

ATM Pilot between Junctions 3A and 7. The structure also offers a mechanism for a rapid

conversion of the document to a more standard Environmental Statement format should the

RoD and NoD process determine that this is required.

5.5 Environmental Design and Potential Generic Mitigation Strategies

The following general design principles and mitigation strategies can be utilised to avoid,

offset and minimise potential adverse impacts associated with the construction and operation

of a MM-HSR scheme:

Careful attention to the minimisation and/or avoidance of earthworks, as far aspractical and avoidance of removal or damage to existing trees and shrubs.

No spoil piles should be left on site, material excavated during trench works shouldbe used to back-fill the trenches and re-grade the verge locally around the trench Soil

handling storage and replacement should adhere to best practice and Standards and

in accordance with any specific requirements to be set out in Appendices to the

Specification.

The preparation of and adherence to a Site Waste Management Plan.

Trenching works should be minimised as well as the size of the plant required toinstall the infrastructure to reduce the overall footprint of disturbance.

The adoption and application of a hierarchical approach to the selection of suitableearthworks retention systems within the scheme, looking to balance the requirements

of retaining the existing soft estate against the avoidance and minimisation of

significant retaining structures (see Section 5.6).

The creation of a family of structural treatments and finishes for retaining systemsand consideration of the requirement for visual barriers where space may be

restricted.


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The use of new tree and shrub planting within the highway boundary to restorescreening or restore landscape character. Guidance on planting distance from the

carriageway is given in DMRB Vol 2 Sect 2 part 8(3.132). Whilst the majority of new

planting should generally consist of transplant size stock, consideration should be

given to a higher proportion of larger planting material to give a more immediate

impact in terms of screening, as successfully implemented on the M42 ATM Pilotbetween J3A and 7. However in designing any landscaping mitigation, due regard

should be given to whether the design is sustainable over the medium to longer term.

The narrower the width, the less likely it is to be sustainable over the medium to long

term, particularly for large trees.

Where there are limited opportunities for new planting/habitat creation within thehighway offsite planting may be considered. This will require the agreement of the

landowner and due to the uncertainties attached it should not be taken into account

during the landscape assessment unless an agreement in principle has been

confirmed.

Minimisation of signs, gantries, etc and other features in terms of both size, numberand, to avoid clutter.

Also consider the identification of wider mitigation opportunities such as offsiteplanting.

The decommissioning and removal of redundant infrastructure, and reinstatement offormer equipment sites.

The adoption of the drainage design, attenuation and pollution control mechanismswhere required. (See Section 5.7).

The potential provision of noise barriers following detailed assessment, in addition tothe adoption of quieter surfacing.

The collation of mitigation strategies and specific (i.e. ecological licences etc)requirements into a comprehensive CEMP to be taken on board and operated by the

successful Contractor.

Consideration of various specific ORs to regulate factors such as speed, if air quality,specific emissions and/or noise levels become problematic.

DMRB Vol 10 in general, and Section 2 in particular, provides guidance on environmental

design issues associated with improving existing roads.


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The following summarise the key design and environmental issues that need to be

considered when finalising the selection and development of a detailed design solution for a

site specific retaining requirement, considering selection criteria and treatment options. This

text is not intended to provide detailed guidance on the various geotechnical options thatmay be required to address site specific issues, but to provide a hierarchy of potential

options, taking into consideration sometimes conflicting engineering and environmental

objectives.

In summary the key design hierarchy selection considerations are;

Is sufficient space available to create a slope re-grading or green

earthworks modification system? (Gradients up to max 450)

If yes then consider the following: would the construction of a slope

realignment or geotechnical solution require the loss of significant amountsof higher vegetation cover in the short and medium term, particularly where

this may be located adjacent to sensitive receptors, if yes then consider

another system, question 2 below, if no then proceed with the design

solution, accommodating opportunities for reinstatement including tree and

shrub planting.

If no then consider next stage in the design solution selection system,

bullet 2.

Is sufficient space available for some form of green faced retention

system? (Gradients between 450and a max of 550)

If yes then consider the following: would the construction of the green

faced retention system (NB also take into consideration temporary

construction land take requirements) require the loss of significant amounts

of higher vegetation cover in the short and medium term, particularly where

this may be located adjacent to sensitive receptors, if yes then consider

another system, bullet 3, if no then proceed with the design solution,

accommodating opportunities for a grass faced retention system;

If no then consider next stage in the design solution selection system,

bullet 3. Space, and or, geotechnical restrictions (i.e. rock cut etc) where some

form of vertical treatment may be required. (Gradients above 550)

If geotechnical considerations allow then utilise stable exposed rock cutting

faces, if however this is not practical then consider appropriate

geotechnical solutions to achieve earthwork stability but accommodate a

facility for a standardised, aesthetically appropriate surface treatment.

The following sections briefly set out issues to be taken into consideration when developing

one of the 3 main retention systems in more detail to address specific site basedrequirements.


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System 1 - Slope Re-grading or Green Earthworks modi fication system

Further considerations when adopting this type of solution at any given location could

include;

The transition from a re-graded slope into the adjacent existing slopes to create aflowing sympathetic design solution.

The retention of as much of the higher vegetation cover as possible at any givenlocation, and the requirement to design in sufficient soil depth to allow for appropriate

mitigation reinstatement works, i.e. a minimum of 100 150mm for seeding and up to

300mm + for areas requiring tree and shrub planting.

The careful segregation of topsoil and subsoil, along with handling to maintain itsviability for use within the scheme, and particularly for the reinstatement of areas of

ecological or other sensitivities. Ecological principles should be adopted during the

preparation of all of the detailed earthworks and top-soiling proposals, with a view tooptimising the ecological benefits.

Consideration of the adoption of a biodegradable surface protection geotextile onsteeper slopes, or slopes subject to particular challenges such as springs, particularly

exposed and or dry aspects.

Consideration of the requirements for a wrap around geotextile solution (preferablybiodegradable) for slopes at the upper end of the range and at difficult transition

interfaces.

The seed mixes should be designed to meet the requirements of the landscape andecological objectives, and would be selected to meet specific design criteria such as;

the need for a bioengineering mix i.e. a mix of grasses and appropriate herbs to

create a rapidly establishing, dense sward capable of withstanding dry conditions in

conjunction with hydroseed ameliorants and binding agents on any steepened or

surface geotextile protected earthworks.

Native species, which match locally typical National Vegetation Classification (NVC)communities should be utilised in seeding areas where possible and practical.

The design of environmentally sensitive, possibly bioengineered, over-steepenedslopes, with particular attention given to transition details where there arerequirements to fulfil landscape and or other mitigation objectives. Possible systems

could consider, utilising biodegradable geotextiles, live willow fascines, mattresses

and stakes. The latter are more appropriate where works may be located adjacent to

ditches, watercourses or damp areas.


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System 2 Green Faced Retention System

Further considerations when adopting this type of solution at any given location could

include;

Adoption of several of the above general bullets with reference to soil handling,transition details, existing higher vegetation retention and appropriate seed mixes to

achieve bioengineering functions, whilst taking note of ecological considerations.

The consideration of a variety of geotechnical solutions such as reinforced earth, soilnailing to undertake the primary retention functions. From experience gained from

the M42 ATM Pilot where sufficient space is available within the Highways Agency

boundary (to accommodate the fully bonded tensile elements) soil nailing provided a

relatively quick in-situ gravity structure which can be installed progressively whilst

minimising earthworks. Reinforced earth however takes longer to install, and requires

greater temporary and permanent earthwork operations and space, hence potentially

requiring larger areas of the soft estate.

Particular attention is required to the transition zone between the retained structureand the existing slopes to avoid issues of local drainage problems, erosion, health

and safety and aesthetic conflicts.

The integration of cells, panels, wrap around geotextile into the overall geotechnicaldesign solution to allow for sufficient depth of soil to sustain a healthy sward (normally

75 100mm minimum). This may also require consideration of a wrap around

geotextile detail, or mat, preferably biodegradable to retain soi

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