8. In November 2004 the Secretary of State for Transport published guidance under section 18 of the Act entitled Network Management Duty Guidance. This sets out in more detail guidance about the techniques of network management and other matters relating to the performance of the duties imposed by sections 16 and 17. In particular Annex A to the guidance, which is headed Good Practice Advice on Techniques and Approach, describes how an authority may achieve effective improvements to the management of road networks. In performing the duties under sections 16 and 17, authorities must have regard for this guidance.