In the context of public transport, real time information (RTI) systems are those systems and services which enable passengers to have current information on the operation of their expected service – rather than merely hoping that the planned timetable is being met.
The most widespread and familiar form of RTI is the at-stop “countdown” service, in which an display indicates the number of minutes until the next numbered service vehicle will arrive. However there are many other options for RTI, which make use of an increasingly rich range of opportunities for data connection and service provision, including services delivered on demand to a person’s mobile phone. While the applications that provide these services will be quite different, they all rely on the same base data, namely real time automated vehicle location or AVL (see section 2).
This collection of base data is transparent to the passenger but is a complex and technically challenging undertaking, subject to a variety of risks and often involving a number of separate systems operating in series. Understanding and addressing these risks is crucial if the public facing RTI is to be kept to an acceptable level of reliability.