1 Introduction

1.1 Background to the Forth Replacement Crossing

1.1.1 Introduction

The Forth Replacement Crossing (FRC) is a major infrastructure project proposed by Transport Scotland, an agency of the Scottish Government. The FRC comprises a new cable-stayed bridge across the Firth of Forth and associated new and improved roads infrastructure to both the north and south of the bridge. The project is driven by uncertainty over the future viability of the existing Forth Road Bridge, and is designed to safeguard this vital connection in Scotland’s transport network. The proposed scheme will retain the existing Forth Road Bridge as a public transport corridor for use by buses, taxis and other specified users and for continued use by pedestrians and cyclists. The new bridge (referred to as the Main Crossing) will be used by all other traffic including private cars and heavy goods vehicles.

Jacobs Arup was commissioned in January 2008 to assist Transport Scotland to develop the FRC proposals. As part of the proposals, Transport Scotland commissioned Jacobs Arup in association with Natural Capital to carry out a sustainability appraisal and other associated work, including management of carbon in the scheme. Since completion of a sustainability appraisal is not a mandatory requirement, this undertaking represents a commitment by Transport Scotland to aspire to national sustainability criteria, together with the project-specific sustainability objectives that have been developed for the FRC as outlined in this report. The management of this process has been lead by a combined core group comprising all three organisations above.

This sustainability appraisal report is based on the Stage 3 design of the FRC proposals.

1.1.2 Location and Site Description

The proposed scheme can be separated into the following three main sections, with overarching traffic management measures supported through the use of an Intelligent Transport System (ITS) which will operate between Halbeath Junction on the M90 and Newbridge Junction on the M9:

the Main Crossing (cable-stayed bridge and approach viaducts);
road connections north of the Main Crossing to Admiralty Junction (M90 Junction 1); and
road connections south of the Main Crossing to Scotstoun Junction (A90/M9 Spur), together with enhancement to M9 Junction 1A.

The Main Crossing

The Main Crossing will be located upstream of the Forth Road Bridge and will consist of a three-tower, cable-stayed bridge and approach viaducts. The total length of the Main Crossing is approximately 2.7km. It will be a dual two-lane motorway with hard shoulders. There will be adequate clearance (more than 47m) under each of the two main spans of the bridge to maintain access for shipping. The Main Crossing will include wind shields.

The Forth Road Bridge will become a public transport crossing alongside the Main Crossing.

Northern Connecting Roads

North of the Main Crossing, the Ferrytoll Junction will be fully reconstructed to cater for all local and longer distance traffic movements using the main crossing. The junction also provides for pedestrian and cyclist movements and public transport access to the Ferrytoll Park and Ride site and to the existing Forth Road Bridge.

The B981 will be realigned over part of its length and will join Ferry Toll Road, west of the Dunfermline Wastewater Treatment Works. This will maintain access to North Queensferry during the construction period and improve the operation and safety of Ferrytoll Junction. The B980 (Castlandhill Road) will also be realigned to separate local traffic from A90 traffic.

Southern Connecting Roads and M9 Junction 1A

To the south of the Main Crossing a new 3.1km section of dual carriageway will be built around the west and south of South Queensferry, to join with the A90 and M9 Spur at the Scotstoun Junction. A new South Queensferry Junction will link local roads (including the A904) to the new road infrastructure and Main Crossing, whilst maintaining pedestrian and cyclist routes.

From the South Queensferry Junction to the Scotstoun Junction the road will be a dual three-lane carriageway with hardshoulders, constructed to motorway standard. The additional carriageway width means that the existing A8000 overbridge will require to be reconstructed. Dedicated public transport links will be provided from the Forth Road Bridge eastwards in the direction of Edinburgh using the A90, and from the A90 to the A8000 westwards to join a proposed bus priority scheme on that road. There will be no change to the existing A90 from the Scotstoun Junction into Edinburgh.

Junction 1A on the M9 will be redeveloped to provide two general traffic lanes on the existing south-facing slip road and loop, to help traffic flow and make better use of the current junction. New west-facing slip roads will be added to better serve West Lothian traffic. The M9 will be widened to provide four lanes of traffic in the southbound direction to complement the proposed improvements to this junction. An additional lane on the M9 will be added in the northbound direction between the River Almond Bridge and Junction 1A to help diverging traffic.

Managed Motorway Measures

Managed motorway measures will be implemented between Halbeath Junction on the M90 and Newbridge Junction on the M9. Overhead gantries and Intelligent Transport System (ITS) components will provide lane control signals, mandatory (variable) speed limits, ramp metering (to regulate the flow of traffic entering the mainline from a slip road) and other functions to improve the operational efficiency of the road network and reduce congestion.

More details on the proposed scheme can be found in the DMRB Stage 3 Scheme Assessment Report (Jacobs Arup 2009a) and Chapter 4 of the Environmental Statement (ES) (Jacobs Arup 2009b).

South of the Main Crossing to Scotstoun Junction (A90/M9 Spur) and M9 Junction

1.1.3 Need for the Scheme

The FRC is required because of the uncertainty over the condition and long-term future of the existing Forth Road Bridge. The crossing over the Forth is critical to the east of Scotland economy, providing a vital link between Edinburgh, the Lothians and Fife.

The condition and operational capability of the Forth Road Bridge has deteriorated over time, primarily because of increased traffic and the effects of weather on the bridge. One of the main concerns in recent years has been the condition of the main suspension cables and whether the bridge can continue as the primary crossing for all traffic, as well as other ongoing maintenance issues.

In February 2008, a study by the Forth Estuary Transport Authority (FETA) reported that it would be possible to replace the bridge’s cables, however this would not be feasible without a replacement bridge being in place because of the severity of the impact on road users and the wider economy. Studies into the rate of cable deterioration are ongoing and the preliminary findings have been taken into account in the design and programming of the FRC proposals.

The FRC has been identified as a key strategic investment project in Scotland’s national transport network in the Strategic Transport Projects Review (STPR) published by Transport Scotland in December 2008, and the National Planning Framework (NPF2) published by the Scottish Government in June 2009.

1.1.4 Scheme Objectives

Eight specific transport planning objectives have been identified for the proposed scheme:

maintain cross-Forth transport links for all modes to at least the level of service offered in 2006;
connect to the strategic transport network to aid optimisation of the network as a whole;
improve the reliability of journey times for all modes;
increase travel choices and improve integration across modes to encourage modal shift of people and goods;
improve accessibility and social inclusion;
minimise the impacts of maintenance on the effective operation of the transport network;
support sustainable development and economic growth; and
minimise the impact on people, and the natural and cultural heritage of the Forth area.

1.2 Purpose and Content of the Sustainability Appraisal and Carbon Management Report

The purpose of this Sustainability Appraisal and Carbon Management Report is to:

summarise the sustainability appraisal process as developed and applied to the proposed scheme throughout its development since January 2008;
appraise the sustainability performance of the proposed scheme against defined sustainability objectives, including the measurement and management of carbon; and
identify design measures (ideas and innovations) that could deliver a more sustainable outcome.

The sustainability appraisal process has also been used to increase awareness of sustainability issues within the integrated project development team and wider stakeholder groups. This was undertaken during the design stages through a combination of workshops and meetings, and has provided a framework for moving forward into the construction phase.

The Sustainability Appraisal and Carbon Management Report is structured as follows:

Section 1: introduction;
Section 2: policy context for undertaking sustainability appraisal;
Section 3: approach to sustainability appraisal;
Section 4: sustainability appraisal: targets, findings and future opportunities;
Section 5: design implications and sustainability;
Section 6: future sustainability monitoring;
Section 7: CEEQUAL; and
Section 8: conclusions.

1.3 Benefits of the Sustainability Appraisal and Carbon Management

The benefits of undertaking this sustainability appraisal and carbon management process are that it:

draws together all the information on sustainability and carbon management relevant to the scheme;
makes sure that the ethos of sustainable design and development is embedded within the project throughout its life-cycle;
encourages a more efficiently designed and effectively delivered scheme; and
demonstrates how the scheme contributes towards the delivery of Scottish Government policies on sustainable development and climate change.

In conjunction with the environmental impact assessment, the sustainability appraisal has also provided a framework for including environmental, social and economic factors in decision-making throughout the life-cycle of the project, thus supporting a sustainable approach. The sustainability appraisal will also support and build on the environmental commitments presented in the ES and Appropriate Assessments.