The invention relates to a method of enquiring for an itinerary and guiding of vehicles using one or a plurality of positioning methods, an electronically stored road system in the form of individual road segments in a centre and an itinerary planning and/or optimal module installed in said centre. The method is characterised in that a mobile communication system comprising a mobile radio network and mobile radio terminals is used; an itinerary is planned in the centre in response to user enquiry, said itinerary being planned according to optimum criteria of the enquiry and/or the vehicle and/or the individual user; a guidance root is generated in the centre, and a chain and sequence (peculiar to each individual itinerary) of road segments is included as important information therein; an individual itinerary is produced in the centre on the basis of the guidance root and additional information and is transmitted to the terminal where it is processed in an essentially independent manner.