A key capability of Intelligent Transportation Systems is communications between the vehicles and the infrastructure and between the vehicles themselves. In particular, vehicles on the roadways carry a wealth of information on their position and velocity that, when aggregated with that from many other vehicles, provides a rich resource for traffic management. The key component is accurate vehicle position at speed. In this study, we will show that accurate position is achievable via mobile devices. We propose to implement a mobile application on an Androids phone that will enable the application to compute vehicle positions, while the vehicle is moving at 65 MPH, with accuracy of 10 feet or less. This implementation will be based on formula and finding from DTR57-12-C-10019, FHWA, SBIR Phase 2, 10.2-FH3-001 study. The key to this implementation is obtaining vehicle speed and heading in real time. We propose to obtain this real-time data via OBDII device connecting to the vehicle OBD port sending out data wirelessly via Bluetooth communications. We propose to record the vehicle position in longitude and latitude together with UTC time and store the data locally in the mobile phone, and at user request, send the data to online server for analysis.