In conjunction with GPS-enabled smart-phones, the method of Floating Car Data (FCD), a part of Intelligent Transportation Systems (ITS), offers faster and cheaper procedure to gather and display real-time traffic data. However, this type of phone at its current state is only able to provide data at low accuracy; thus, additional procedures are required to improve the data accuracy. In this research, an FCD-based monitoring system with virtual trip line (VTL) is designed and implemented, and some formulas are used in the proposed algorithm to minimize the data error. The developed system and...