Entry for the derivation of general measures were analysed both domestic and foreign proceedings from practice and from the literature. From the activities of cantonal and municipal police forces, the advisory activities of the BFU and the IVT further insights into methods to derive general measures could be found.
Entry for method of deriving local measures a great abundance in the literature new date is available. There were also over 20 years of experience the Zurich cantonal police, backed by 30 years of experience of the IVT at ETH Zurich and the BFU.