Houston Freeway Night

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:

Anonymous Wireless Address Matching (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.

Bluetooth Diagram

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.

A Note About Privacy

The MAC addresses read by AWAM are not directly associated with a specific user and do not contain any personal data or information that could be used to identify or "track" an individual's whereabouts. In addition, all addresses collected by AWAM are anonymized through encryption immediately upon receipt. Users who have privacy concerns are also able to turn off the Bluetooth discovery function of their device which prevents it from being read by AWAM at all.

Unlike the applications on a smart phone that use the GPS functionality, AWAM does not have the ability to "track" vehicles or devices everywhere they go. Also, unlike these applications, AWAM cannot correlate a device address with an individual or vehicle so determining who the device belongs to is virtually impossible. Alternative methods for gathering traffic data, such as those used by GPS (which is utilized by virtually every smart phone) or license plate recognition are more likely to warrant privacy concerns.