Online and post-processing of AVL data in public bus transportation system

For a number of years vehicle fleet tracking systems are in use in companies operating large number of vehicles in the field. Proliferation of cheap and compact GPS receivers had the effect that Automatic Vehicle Location (AVL) systems today almost exclusively use satellite based locating systems. This paper presents characteristics of realized system tracking and analyzing city bus transit traffic in the city of Nis. Since the described system also uses GPS for vehicle location, initially, data about vehicles' locations acquired from AVL subsystem need to be transformed into form that is adequate for further usage in the system, analysis and prediction. Also, city bus transit tracking systems are specific concerning functionalities differing them from other vehicle fleet tracking systems. These specifics include cyclic vehicle routes, the need for specific performance reports etc. This paper specifically deals with vehicle motion prediction with on station arrival time estimation coupled with automatic report generation.