12D M4 is for persons wishing to become Registered Traffic Management Convoy Working Operatives as described in the Sector Scheme Document 12D. To become a registered 12D M4 Operative, the learner must have completed the NHSS 12D T1/T2 course and either be in the process of being registered as a 12D M2 Operative or already be a registered 12D M2 Operative prior to applying for registration. Following completion of the 12D T4 training course the learner will need to:

undertake a single on site assessment as prescribed in the Sector Scheme Document to obtain the category. The assessment must be completed within a two year period starting from the date of passing the training. Each learner must be assessed individually – “whilst undertaking traffic management operations, including assessment of capability, unregistered Traffic Management Operatives shall at all times be supervised by an appropriately registered Traffic Management Operative on a one to one basis” – NHSS12D Sector Scheme Document, page 22, 6.2.1(i). Minimum competency requirements for gang sizes are shown on page 23 of the document – these must be maintained whilst assessments are being carried out.