Crossrail 2 – Development and Application of an Appraisal Framework for Crossrail 2 in London

Crossrail 2 – Development and Application of an Appraisal Framework for Crossrail 2 in London


Jameel Hayat, AECOM, Stephen Pauling, Transport for London, Andrew Mak, Transport for London


Crossrail 2 is one of the main options to support London's growth. This paper reviews the approach to appraisal, analysis and modelling to inform the decision-making process and how these were drawn together to help develop and refine the scheme.


Crossrail 2, previously known as the Chelsea-Hackney line, is being promoted by Transport for London (TfL) and Network Rail as one of the key long-term projects needed to support London's rapid growth. It would provide additional rail capacity between south west and north east London and beyond. The concept of cross-London tunnelled rail services connecting mainline services first emerged in the 1944 Greater London Plan with a focus on east-west services. It was six decades later, however, before construction on Crossrail commenced in 2009 and trains are due to begin operating in 2018.

In 1991 a north-south Crossrail 2 route, envisaged at that time as a metro line, was safeguarded to protect it from development. However, with the emphasis on east-west Crossrail, the Crossrail 2 route was not progressed until more recently. In 2008 the safeguarding for the line was refreshed and in 2009 the Department for Transport (DfT) asked the Mayor of London to review the case with a view to re-examining the thinking behind the scheme, identifying new options and refreshing the safeguarding.

Extensive optioneering work has been undertaken in order to determine the nature, scale and benefits of the scheme with a view to delivering the scheme during the 2020s. In May 2013 two options went to public consultation, a metro option between Wimbledon and Alexandra Palace with up to 40 trains per hour and a regional rail option with up to 30 trains per hour operating from Alexandra Palace and Hertfordshire to various locations in south west London and Surrey. Either option would be a significant undertaking and become one of Europe’s largest infrastructure projects.

Taking into account updated population and employment forecasts for London, revised modelling work to examine long term needs and capacity constraints, updated economic appraisal and engineering feasibility assessments, and responses to the consultation, TfL commenced another round of optioneering for Crossrail 2. The potential scale and complexity of the scheme, both in terms of construction and operations, as well as impacts ranging from significant wider regional economic effects to local impacts on landscape, regeneration and development, in a constrained funding environment have necessitated a comprehensive approach to scheme appraisal.

A key aspect in taking this forward has been the development of an appraisal framework that provides a robust and transparent mechanism for identifying and demonstrating how the preferred options have been selected and provides policy and decision makers with confidence to make an informed decision on the preferred scheme and safeguarding the route from development, taking into account value for money, affordability and deliverability as well as meeting national, regional and local objectives.

The development of the framework has involved a review of TfL’s Strategic Appraisal Framework, DfT guidance and other studies, including Crossrail, HS2 and the Northern Line extension in London. A substantial evidence base has been built up and additional work commissioned, ranging from conventional transport business case assessments to economic analysis of wider impacts, through to identifying the potential regeneration and local development impacts associated with various station options.

With such a wide body of evidence and route options to consider, a key issue has been to keep the analysis and appraisal proportionate whilst demonstrating that the right option has been chosen. This is imperative, with further consultation likely, including consultation on updating the safeguarded route, Public Inquiry and the need to demonstrate a strong case for a scheme likely to be similar in scale, cost and complexity to the Crossrail scheme currently being built.

This paper provides a review of the approach to appraisal adopted for Crossrail 2, the additional analysis and modelling undertaken to inform the decision-making process and how these were drawn together to help develop and refine the scheme.


Association for European Transport