Abstract
Real-time passenger information is becoming common in European cities. For public transport, this relies on the ability to trace where vehicles are at any time. Examples are given of passenger information systems on the railways, which are based on data from the signalling system. For buses and tramways, tracing the vehicle position is more complicated and satellite global positioning systems are often used. The real-time data information system in Helsinki's HELMI Public Transport Telematic System in Finland is described. Methods for disseminating information to the public are outlined: visual displays at bus and tram stops, on-board displays and audible information on trams and buses, information via the internet and mobile telephones.