Houston TranStar uses various technologies to measure the average speed and travel time of vehicles as they travel along a roadway. Information collected from these technologies is the source for providing travelers with traffic information in various formats including:
- The color-coded speed map on the Houston TranStar Website.
- Travel time messages on roadside message sign.
- Information used by radio and television media for reporting traffic conditions.
The primary source for measuring speeds and travel times in the Houston region has been from the use of toll tag information. Recently, the Houston TranStar partners have been implementing traffic sensors that make use of Anonymous Wireless Address Matching (AWAM) to measure speeds and travel times along roadways.
Anonymous Wireless Address Matching Using Bluetooth
Houston TranStar’s AWAM System detects vehicles equipped with enabled Bluetooth networking devices, including cellular phones, mobile GPS systems, telephone headsets, and in-vehicle navigation and hands-free systems.
Every Bluetooth device has an electronic address, known as a MAC address, used to identify it to other network devices. Each roadside AWAM reader senses these addresses emitted by enabled devices as they pass the reader station.
For real-time applications, the AWAM reader then transmits the time and location of the device to the AWAM host processing system at Houston TranStar. As probes are detected at successive AWAM readers, the host system merges travel time readings to calculate average travel times and speeds for a roadway segment.
Source: http://traffic.houstontranstar.org/bluetooth/transtar_bluetooth.html
