Door-opening collision accidents between motor vehicles and vulnerable road users occur frequently and pose serious risks to road traffic safety. No mandatory UN Regulation or Global Technical Regulation for Door Opening Warning Systems exists internationally, resulting in regional inconsistencies. A virtual kick-off workshop was held on 1 April with participation from contracting parties and stakeholders. The workshop reviewed accident data from Germany and China, discussed potential technical parameters for DOWS, and identified the need for broader international data collection. Further workshops are envisaged pending availability of substantive new input.