The quantity of data stored varies by site depending on the flow and the frequency of retrieval. The Swiss measuring site has been in operation since 2005 while the UK sites have been established over the past 4 years. In the UK for example, the data are stored in binary format and telemetry used for data collection whilst in Switzerland the use of the Internet has proved to be successful. The advantages of these types of data connections are that the user is able to monitor the performance and “health” of the FMS remotely. To compare the environmental footprint of vehicles in the UK with those in Switzerland a harmonized vehicle classification system was used. As both countries use their own classification system, a conversion was made from these national schemes to COST 323 classification (Table 1).