Design of trunk roads

Transport Scotland ensures that trunk roads are designed with the most up-to-date standards to ensure they:

• Adhere to the design standards in the Design Manual for Roads and Bridges
• Are safe and accessible to all users

The Design Manual for Roads and Bridges (DMRB) is a suite of documents which contains requirements and advice relating to works on motorway and all-purpose trunk roads for which Transport Scotland as Overseeing Organisation is the road authority.

The DMRB embodies the collective experience of the Overseeing Organisations, their agents, supply chain members and industry bodies. It provides requirements and advice resulting from research, practical experience of constructing and operating motorway and all-purpose trunk roads, and from delivering compliance to legislative requirements.

Competence

The DMRB has been prepared for use by competent practitioners, typically qualified professionals able to work independently in relevant fields, who are expected to apply their own skill and judgement when making decisions involving the information that the DMRB contains.

The Design Manual for Roads and Bridges

The Design Manual for Roads and Bridges sets a standard of good practice that has been developed principally for the trunk road and motorway network. It may also be applicable in part to other roads with similar characteristics. Where it is used for local road schemes, it is for the local roads authority to decide on the extent to which the documents in the manual are appropriate in any particular situation.

In addition to the DMRB, the following documents remain applicable to trunk roads projects in Scotland:

• TD 37/93 Scheme Assessment Reporting
• TA 46/97 Traffic Flow Ranges for Use in the Assessment of New Rural Roads
• TA 79/99 Traffic Capacity of Urban Roads [Incorporating Amendment No.1 dated May 1999]

These documents are available on request from Transport Scotland. These documents are also available on the archive of DMRB standards.

Link with Manual of Contract Documents for Highway Works

The requirements and advice given in DMRB documents are provided on the basis that the works are constructed in accordance with the Manual of Contract Documents for Highway Works (MCHW).

The MCHW is a standard suite of specification documents which are included within a construction contract.

Other guidance

Within the DMRB, Transport Scotland publications Cycling by Design and Roads for All: Good Practice Guide for Roads are referenced and set out guidance which is used in the design of the trunk road and motorway network.

Transport Scotland Interim Amendments (TSIAs) are instructions which replace or compliment the design standards, and are applicable only in Scotland. Whilst all TSIAs must be read in conjunction with the DMRB and the MCHW, and may incorporate amendments or additions to documents in these manuals, they are not part of either documents.

Note: The PDFs may not be fully accessible. Please contact info@transport.gov.scot if you wish to request the document in a different format.

52 - April 2022 - Road Recycling

51/22 – April 2022 – Skidding Resistance

49 - November 2018 - The use of Griptester on the Scottish trunk road network

46 - May 2016 - TS IA 46/16 - Structures Inspector Competencies and Certification

45 - Mar 2014 - TS IA 45 - Management of Abnormal Loads 28 3 14

44 - May 2013 - Simplified Design Method for the Crack, Seat and Overlay Method - Notes for Guidance

38 - May 2011 - Temporary Barrier Decision Tool (TBDT)

36 - Dec 2010 - Guidance on structural safety reporting relating to the Scottish Trunk Road Network

35/18 - Nov 2018 - Guidance on the Introduction of Transport Scotland TS 2010 surface course specification

23 - Revision 3 Jan 2015 - Implementation of BS8500-1:2006 Concrete – Complementary British Standard to BS EN 206-1

21 - Oct 2006 - Principal and general inspection of sign / signal gantries, and gantries with low handrails or open mesh flooring (BD 63/94 and BA63/94)

Any enquiries should be directed as listed at the end of the Interim - Amendment.

See an archive of withdrawn Transport Scotland Interim Amendments

The purpose of the Transport Scotland Departures from Standard Advice and Procedures Guide is to provide interested parties with the necessary guidance to apply for departures from the standards.

Where requirements of the DMRB or MCHW are not met, a departure application shall be submitted in accordance with the procedures:

1. before the design is finalised, and
2. prior to their incorporation into the works