Bluetooth sensor data is like probe-based data but is more localized and needs specialized hardware. Most vehicles manufactured today are equipped with Bluetooth devices, as are personal electronics such as phones, laptops, and tablets. Bluetooth sensors used for traffic engineering scan for other Bluetooth-enabled devices near the Bluetooth sensor device. Once a device is read by the Bluetooth sensors, it stores data related to the detected device. This data can be used to conduct OD studies, determine vehicular density, and conduct flow analysis. When using Bluetooth sensors for traffic engineering, the placement of these sensors is key. Placing these sensors under overpasses, or where multiple roadways are crossing over or under each other, may create challenges, such as not being able to identify the overpass or roadway on which the device was read. This can also occur at intersecting roadways with many pedestrians with cellphones. Post-processing of this data to minimize such issues is suggested. This method only gathers information for vehicles with Bluetooth devices present in the vehicle.