Travel time is one of the oldest performance measures used to characterize transportation systems. Direct measurement of travel times has traditionally been based on license plate matching techniques (2) in vehicle notes, mechanical devices attached to odometers (3), or Global Positioning System (GPS) recording devices (4). More recently, cell phone and toll tag tracking has been proposed as mechanisms for collecting probe vehicle link travel times (5-7 ). A variety of published statistical techniques document the estimation of sample size or sample proportion necessary for reliably estimating travel time (3,7,8).This paper reports on the use of a technique to log and to timestamp wireless MAC addresses acquired from detectable Bluetooth devices in vehicles that pass selected sample locations. MAC addresses are unique 48-bit addresses assigned by manufacturers of many consumer wireless electronic devices, such as cell phones, laptops, hands-free headsets, MP3 players, and GPS devices that have either Wi-Fi or Bluetooth capability. Because each MAC address is unique, traditional matching algorithms analogous to those used for license plate, cellular, or toll tag tracking can be used to estimate travel time, space mean speed, or both between observation points (9). The arterial MAC reader data are particularly useful for measuring fluctuations in traffic patterns and more accurately measuring the impacts of changes to the transportation system, such as new signal timing or new roadway lanes.More specifically, this paper will introduce the MAC reader technology, show how it is validated, and demonstrate how professionals are using the data to solve transportation issues on the ground. The case study for this pilot project is Tualatin-Sherwood Road in Tualatin, Oregon, about 15 mi southwest of Portland (Figure 1). This regional major arterial connects Interstate 5 and the neighboring cities of Tualatin and Sherwood, Oregon. The 2.5-mi test section includes 10 signalized intersections and carries average daily traffic (ADT) of 15,000 to 20,000. The study corridor is shown in Figure 1.A series of two deployments that used the MAC address readers was conducted along Tualatin-Sherwood Road. In summary,• Test 1 deployed three MAC readers covering the same corridor as manual travel time runs that were conducted by means of the floating-car methodology. The purpose of this study was to validate the technology as reasonably replicating vehicle travel times over a corridor to establish confidence in further research evaluation.• Test 2 deployed six MAC reader units to collect more refined data by using the MAC readers to capture travel times after signaltiming adjustments were made to quantify the benefit of the changes over the corridor under a before-and-after evaluation of scenario segments.This study reports on the use of media access control (MAC) readers through the Bluetooth protocol by means of off-the-shelf equipment to measure arterial travel performance (segment travel time, average running speed, and origin-destin...
