A passenger information [display] system (PIS or PIDS) is an electronic information system which provides real-time passenger information. It may include both predictions about arrival and departure times, as well as information about the nature and causes of disruptions. It may be used both physically within a transportation hub and remotely using a web browser or mobile device. Train operating companies are constantly striving to improve passenger satisfaction by offering more than just arrival and departure times.

Current operational information on service running is collected from automatic vehicle location systems and from control systems, including incident capture systems. This information can be compared by computers with the published service timetable to generate a prediction of how services will run in the next few minutes to hours.

This may be informed by additional information: for instance, bus services will be affected by congestion on the road network, while all services may be affected by adverse weather conditions.