Guidance

TAG unit A3 environmental impact appraisal

Guidance on the analysis of environmental impacts in transport appraisals.

• From: Department for Transport
• Published: 31 May 2019
• Last updated: 28 November 2024 — See all updates

Documents

TAG unit A3 environmental impact appraisal

PDF, 988 KB, 118 pages

TAG unit A3 environmental impact appraisal, including forthcoming changes for May 2025

PDF, 909 KB, 114 pages

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Forthcoming change: base year update

https://www.gov.uk/government/publications/tag-forthcoming-changes/forthcoming-change-base-year-update

Details

This document gives guidance on environmental impact appraisal.

The previous version of this guidance was published in November 2023.

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.

Published 31 May 2019
Last updated 28 November 2024 + show all updates

1. 28 November 2024

   Updated with forthcoming changes for May 2025.

2. 30 May 2024

   TAG unit A3 updated.

3. 25 April 2024

   Forthcoming changes added.

4. 30 November 2023

   TAG unit A3 guidance updated.

5. 19 October 2023

   Added forthcoming change about appraisal guidance updates.

6. 6 October 2023

   Added forthcoming change about carbon valuation.

7. 31 May 2023

   TAG unit A3 guidance updated.

8. 19 April 2023

   Added forthcoming change: spring 2023 data book and guidance updates

9. 30 May 2022

   Unit A3 guidance updated.

10. 29 April 2022

    Forthcoming change to guidance note added, the note details guidance alterations to be implemented in May 2022.

11. 30 July 2021

    Updated with new version of unit A3 guidance.

12. 19 May 2021

    Updated TAG unit A3 guidance.

13. 13 August 2019

    NO2 changed back to NOx in 3.2.7 following Department for Environment, Food & Rural Affairs clarification.

14. 6 August 2019

    Information updated for technical errors NOx changed from NO2 in 3.2.7 and 3.4.4.

15. 31 May 2019

    First published.