The Department for Transport’s Business Case guidance sets out how write a full business case for a transport investment.
This includes:
- Guidance on the HMT Green Book 5-case approach applied to transport schemes.
- An Early Assessment and Sifting Tool for short-listing options at an early stage of the project or programme development.
- Guidance on Value for money assessments.
- Guidance on enabling behaviour change.
In additions to these guidance documents, DfT provides additional resources to estimate the impacts of transport investments, such as:
- WebTAG – the guidance for appraising economic, social and environmental impacts of transport investments (relevant for the Economic Case).
- A carbon tool for local authorities to estimate environmental impacts of transport investments.
- A behavioural insights toolkit.
- Transport impact evaluation guidance.
More resources are available on the DfT website here.