This requirements, concept and creative brief document is the outcome of a preliminary phase of research including an extensive literature review and human-centred design workshop data collection and analysis focusing on the design of an Acoustic Vehicle Alerting System (AVAS) for zero-emission buses. The brief integrates knowledge from the transport safety literature, sound design and engineering and the analysis of local stakeholder needs. The document forms part of the second milestone deliverable for iMOVE project 6-026 AVAS Soundscape.<p></p>