The Department provides guidelines for the appraisal of transport projects and programmes through the Common Appraisal Framework (CAF). The guidance is informed by, and works in tandem with, the Public Spending Code as well as international transport appraisal practices and research.

Properly conducted appraisal informs policy makers as to the economic value of projects and enables them to compare the value of several different projects under one consistent measurement.

The current appraisal guidance was published by the Department in February 2016. The updated guidance replaces the 2009 iteration entitled ‘Guidelines on a Common Appraisal Framework for Transport Projects and Programmes’. The 2016 CAF updates appraisal values for existing parameters and introduces a new parameter of active travel benefits. The 2016 guidance also includes some changes in appraisal process, which reflect requirements from the Public Spending Code.

There is an ongoing programme of work to expand and supplement the CAF. The first tranche, which will be finalised in early 2017, will review the feasibility of including parameter values for ambience and reliability in travel times. Further work will seek to include Wider Economic Benefits (WEBs) of transport projects and programmes, and the treatment of PPPs in an appraisal context.

Although the parameter values are only relevant for transport projects and programmes, the appraisal methods and processes outlined in the CAF are valid for all projects under DTTAS’ remit, including sport and tourism expenditure. People seeking to appraise projects in these areas should first read the CAF to get an understanding of the requirements involved in appraisal generally, and then contact SRAD (formerly EFEU) to discuss the appraisal of their specific projects.

Click here for the 2016 Common Appraisal Framework

For any queries on the Common Appraisal Framework or to receive future updates, please contact with CAF in the subject heading.


 CAF Sections -  Overview

Section 1 - Overview of project development process

This section gives an overview of the project development process and the scale of appraisal required for certain thresholds.

Section 2 – Preliminary appraisal

This section outlines the preliminary appraisal process and the principles to be followed in developing a series of options.

Section 3 – Overview of detailed appraisal process

This section provides an overview of how a detailed appraisal should be undertaken and the types of acceptable analysis tools and methods that should be employed.

Section 4 – Detailed guidance on appraisal techniques

This section gives detailed guidance on the types of analytical techniques that should be applied when carrying out a detailed appraisal.

Section 5 – Detailed guidance on appraisal parameters

This section outlines the various parameter values which are required when carrying out an economic analysis.

Section 6 – Implementation, monitoring and evaluation

This section outlines how to set up the project or programme so that impacts can be measured at a later stage and the types of formal analysis that are used for evaluation.

Section 7 – Templates

This section provides templates which should be used by the Sponsoring Agency when reporting to the relevant agency or Department.

Annex 1 – Parameter values

This annex sets out the key official parameter values to be used in the appraisal of transport projects and programmes for which the Department of Transport, Tourism and Sport or its agencies are Sanctioning Authorities.

Key Terms

CAF Data Book  - (Please contact SRAD if you would like to access a copy of the Data Book)

The CAF data book includes all of the appraisal and modelling values referred to in the guidance in one workbook.


Common Appraisal Framework - Complete Document