S30115 Drainage Technical Standard Committee DMRB and MCHW cyclic reviews and delivery of updates

National Highways "the Client" is seeking to set up a contract for the provision of technical services to undertake an update of the Design Manual for Roads and Bridges (DMRB) with Drainage content. The DMRB drainage update is required as part of a cyclical ongoing process to improve the DMRB so that the Strategic Road Network and its users continue to benefit from modern technologies and practices. National Highways maintains a register of errors and potential improvements for the DMRB Drainage documents.

It is National Highways' objective to resolve these errors and incorporate the improvements into the DMRB. There are upwards of 250 unresolved items on the register which range significantly in scale. The most straightforward are, for example, a simple edit to change a requirement to a recommendation.

The most complex might be to undertake research to fill a knowledge gap before including a new section in the DMRB. These unresolved items have been reviewed and prioritised by National Highways and have been divided into three categories Must, Should and Could. Through this contract, National Highways' objective is to address all items categorised as Must.

Should and Could items will then be addressed in that order, with the aim to also complete all Should items and as many of the Could items as time and budget allows. The priority categorisation will be reviewed by National Highways at the start of the contract and periodically as the works proceed. The items will require updates to all 20 drainage documents.

These are: - DMRB CG 501 and CG 502 - DMRB CD 521 to CD 536 (inclusive) - DMRB CS 551 - MCHW CC 500 The contract will run for over 2 years until the end of March 2029. The last of the documents will need to be signed off for publication by the end of the contract.