Share an article talking about passenger information system which is close to our daily lives.
Passenger information display systems (PIDS) deliver information to waiting passengers through displays hung above the platform or from the edge of the bus shelter and are increasingly being used to send information through smartphone apps and websites. But however the messages are received they are sent using the same basic system. The vehicle has automatic vehicle location (AVL) in the drivers cab, this is then delivered to a database which compares that information against a database and provides a prediction of when the vehicle will arrive.
The most complicated part of this process is the AVL. Automatic vehicle location uses either a single or a combination of methods to obtain its data.
Signpost systems use a system called signpost transmitters which tracks the vehicle using a series of transponders or RFID chips along the vehicles' routes. As each transponder is passed the vehicle "handshakes" the signpost transmitter and the data is then transmitted to a call center where it is monitored and sent to the message boards or apps.
The other method is GPS, with its ubiquity, GPS systems provide an even more reliable way of tracking vehicles. They operate in the much the same way as a car navigation system in that they receive positioning data from the satellites, the difference is that the information is then sent via radio or GSM to the control center and then onto passengers......