You will need this licence if you intend to occupy a New South Wales State road for activities involving modification to a state road asset. Examples of developmental activities include new constructions or major upgrades or redevelopments, road maintenance including kerb and gutter repair, road widening, repair or construction of road signs, and road re-surfacing.
The licence applies to the occupation of the road space only and does not imply permission or approval for the actual (physical) works being undertaken - you will need to obtain any other approvals or licences from the relevant Agencies.