By now, it’s no secret: the certification requirements for cars in the EU and in Switzerland have precious little to do with the cars’ actual exhaust emissions on the roads. The “real” exhaust emissions are, therefore, determined in separate studies, including at Empa. Air pollution control experts from the Federal Office for the Environment (FOEN) draw upon this kind of data if they want to estimate road traffic emissions. On behalf of the Swiss government, Empa measures about a dozen vehicles a year, which are supplied by randomly selected individuals for a small fee. The data is fed into the European HBEFA database (Handbook Emission Factors for Road Transport) and is used, amongst other things, by international research institutes and authorities as a basis for expert reports.