Status report on two workshops on Door Opening Warning Systems held virtually on 1 April 2026 and 2 September 2026. The first workshop presented accident data from Germany and China and conducted exploratory discussions on system parameters. The second workshop presented accident data from Germany, China, Belgium, the United Kingdom and France, and introduced draft regulatory text covering scope, definitions, signalling strategy, operational parameters, activation and deactivation, failure detection and test procedure. Comments were received from industry, cyclists’ organisations and Contracting Parties. The experts from China and Germany propose establishment of an informal working group on DOWS to develop proposals concerning justification and problem definition, scope and definitions, performance requirements, test and assessment procedures, and regulatory form.