Design for new pavement foundations (formerly IAN 73/06 revision 1 (2009), HD 25/94). Version 1.1.0

DMRB: Pavement CD 225 Version 1.1.0

National Highways, 2025
Design for new pavement foundations (formerly IAN 73/06 revision 1 (2009), HD 25/94). Version 1.1.0 Download document

Document Status

Current

Supplement

Civil & Structural Supplement

Series

DMRB: Pavement

Abstract

Outlines the design requirements for pavement foundations, covering subgrade assessment, foundation designs, performance procedures and design outputs.

History

Pavement. Design. Supersedes CD 225 Revision 1. Design for new pavement foundations (formerly IAN 73/06 revision 1 (2009), HD 25/94). Revision 1 (HE, 2020). Revision 0 dated March 2020 - replaces IAN 73/06 Revision 1 (2009) and HD 25/94. Revision 1 dated April 2020 - clarification re-laid function tables. Version 1.1.0 - dated September 2025. Incremental changes to requirements, based on 5 years experience of using CD 225 and cyclic review.

Subjects

  • Roads
  • Civil engineering, infrastructure and public utilities
  • Transport facilities
  • Road pavement

Publisher History

National Highways is an executive non-departmental public body, sponsored by the Department for Transport. It has responsibility for operating, maintaining and improving motorways and major A roads in England. Formerly known as Highways England, between 2015-2021 and Highways Agency, between 1994-2015.

Information

NBS

NBS has produced specification systems and information products for construction industry professionals for more than 40 years. The National Building Specification is the recognised UK national standard and is used by over 5,000 organisations. NBS is part of RIBA Enterprises Ltd.

Accuris

We connect trusted knowledge to customers' workflows – mitigating risk, increasing efficiency and accelerating innovation For more than 60 years, leading R&D and engineering-intensive organizations have relied on us to achieve on-time, on-budget delivery of complex projects and new products. We deliver an unparalleled combination of technical content and Artificial Intelligence (AI) technologies to surface answers from the vast universe of technical knowledge, both inside and outside the organization. In a single interface, we connect the dots between information scattered across many different sources, allowing technical professionals to make better, more informed decisions faster.