Although travel time is a widely-used highway performance measure, it canbe difficult to estimate. Since consumer electronics such as cell phones, MP3 players and global positioning system devices with Wi-Fi or Bluetooth capability already contain unique digital fingerprints called media access control (MAC) addresses, they offer promise as a way to collect link travel times. This paper reports on the use of a prototype system to log and time-stamp wireless MAC addresses at selected sample locations. If these unique MAC addresses are simultaneously logged at multiple locations, the unique MAC addresses can be matched using traditional matching algorithms, and the difference in time stamps can be used to estimate travel time.A field study was conducted at arterial and freeway corridor locations inIndianapolis to evaluate the use of time-stamped MAC addresses acquired from Bluetooth devices to estimate freeway and arterial travel times. Findings indicate that travel time trends were easy to discern by visual inspection and demonstrate the feasibility of using MAC address matching for travel time estimation. Data from arterial highways showed a significantly larger variance compared to data from the freeways due to the impacts of traffic signals and the noise that is introduced when motorists divert fromthe network. Potential future applications of this technology are described.
Samenvatting