23. The expert of WBU presented a position paper (GRB-61-15) with concerns about an Audible Vehicle Alert System (AVAS) of Quiet Road Transport Vehicles (QRTV). He stressed that AVAS must fulfil four criteria, namely presence, direction, location and operation of a hybrid electric or electric vehicle. He further explained that the AVAS sound must be detectable and locatable, AVAS must be on while the vehicle is stationary and that the driver should not be able to switch off (or pause) AVAS.