Manufacturing representatives (e.g. car manufacturers, filter manufacturers etc.), test institutes (e.g. Dekra and TÜV), local authority representatives (e.g. Berlin Senate, Federal Environmental Office, BMU (Federal Environment Ministry) BMVBS (Federal Ministry of Transport, Building & Urban Development), association representatives, e.g. NABU, BUND, VCD, ADAC (German Automobile Club), VDA (Automobile Industry Association), representatives from the Chamber of Crafts and workshop associations, as well as the staff of elected representatives from all political parties in the German Bundestag meet every six weeks to exchange information on a wide range of topics on traffic and air quality control. Especially these meetings allow a discussion about the practical feasibility of measures and the compliance with limit values. The expert talks enable the exchange of current scientific knowledge and the development of joint strategies and planning activities.