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Guidance

TAG unit A1-1 cost-benefit analysis

Transport analysis guidance (TAG) on the principles of cost-benefit analysis and how they should be applied in the context of transport appraisals.

Updates to this page

From:
Department for Transport
Published:
31 May 2018
Last updated:
28 May 2026
Show all updates

  1. 'TAG unit A1-1 cost-benefit analysis' updated and 'Weighted average life example financial model' file added.

  2. Added forthcoming changes on Green Book update.

  3. TAG unit A1-1 updated.

  4. Updated with forthcoming changes for May 2025.

  5. TAG unit A1-1 updated.

  6. TAG unit A1-1 updated.

  7. Added forthcoming change: spring 2023 data book and guidance updates.

  8. TAG unit A1-1 updated.

  9. Forthcoming changes for November 2022.

  10. Updated with new version of unit A1-1 guidance.

  11. First published.

Documents

TAG unit A1-1 cost-benefit analysis

PDF, 682 KB, 39 pages

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Weighted average life example financial model

125 KB

This file may not be suitable for users of assistive technology.

Request an accessible format
If you use assistive technology (such as a screen reader) and need a version of this document in a more accessible format, please email webmasterdft@dft.gov.uk. Please tell us what format you need. It will help us if you say what assistive technology you use.

Details

Assessment and evaluation of transport investments guidance including cost-benefit analysis:

  • principles
  • reporting

The previous version of this guidance was released in May 2025.

TAG provides information on the role of transport modelling and appraisal, and how the transport appraisal process supports the development of investment decisions to support a business case.

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