Highway Projects

Following the Government's Integrated Transport White Paper and Roads Review, the New Approach To Appraisal has been adopted for the appraisal of all major highway projects. The appraisal methodology was first set out in the Guidance on the Methodology of Multi-Modal Studies (GOMMMS) and is now fully incorporated into Transport Analysis Guidance (TAG). It is necessary to move highway appraisal onto this methodology to maintain consistency with the Multi-Modal Studies and with the appraisal of other modes.

Prior to the adoption of the New Approach To Appraisal, the definitive guide to environmental assessment of highway schemes has been the Design Manual for Roads and Bridges Volume 11. While this guidance remains current, it now needs to be applied in a manner consistent with the New Approach To Appraisal as set out in TAG.

The link between GOMMMS and DMRB was provided by Applying the Multi-modal New Approach to Appraisal to Highway Schemes ("The Bridging Document"). The Bridging Document was written to enable those carrying out highway project appraisal to interpret the multi-modal, study-based, appraisal advice in GOMMMS. It provides the guidance needed to ensure that the appraisal of highway economy and safety impacts is in line with the approach set out in GOMMMS. It also provides advice on the need for a change in the approach to scheme design and development, to reflect the need for a balanced improvement across all five objectives, rather than the maximisation of transport economic efficiency and safety. The Bridging Document has now been fully integrated into TAG.

Key Entry Points:

Introductory Material

An Introduction to Transport Analysis, (TAG Unit 1.1) provides a brief guide to the appraisal process for transport facilities.

Trunk Roads: Applying the Multi-Modal New Approach to Appraisal to Highway Schemes (TAG Unit 1.3) provides an overview of the application of appraisal to highway schemes.

Guidance for the Project Manager

Applying the Multi-Modal New Approach to Appraisal to Highway Schemes (TAG Unit 2.6) provides greater detail on the correspondence between the TAG Appraisal Summary Table and DMRB.

Guidance for the Expert

Modelling (TAG Unit 3.1) and Appraisal (TAG Unit 3.2) introduce the specialist advice that the expert user will follow in developing highway schemes. These lead on to the TAG Units that set out the methodology for the appraisal of each of the Government’s five Objectives for transport. Guidance on the correspondence between the advice in TAG and DMRB (derived from the Bridging Document) is given at the end of the guidance for each sub-objective.

A full list of TAG Units is available on the Documents page.

Further information:

The policy background to the development of the New Approach to Appraisal and the Multi-Modal Studies is set out in more detail in A New Deal for Transport, The Government's White Paper on the future of transport (DETR, 1998) and A New Deal for Trunk Roads (“The Roads Review”) (DETR, 1998). These documents are available on the DfT website - see Transport Policy Links.

Links to the Design Manual for Roads and Bridges (DMRB) are given in the Appraisal Links page.