company news about RFID Readers Installed at U.S.-Mexican Bridges to Help Ease Traffic Congestion

By Claire Swedberg

Nov. 21, 2011—Trucks play a major role in bringing goods across the border into the United States from Mexico through several dozen land ports of entry (POEs), and their sheer volume frequently causes congestion at the ports as the vehicles proceed through inspection by agencies on both sides of the border. To gauge the amount of congestion, however, the U.S. Customs and Border Protection (CBP) has historically depended on reports from drivers regarding their wait times, as well as on visual inspections conducted by officers regarding queue lengths. This information is posted on the CBP's Web site, and is shared with other governmental entities.

The drawback, however, is that the information has been anecdotal, and thus not as accurate as an automated solution would be.

A work crew installs RFID readers above the roadway at the Bridge of the Americas, in El Paso, Texas.

In 2007, researchers at Texas A & M University's Texas Transportation Institute (TTI), together with private research and development organization Battelle, began applying RFID technology to help gauge north-bound traffic at the Bridge of the Americas (BOTA), in El Paso, Texas. The system developed employs RFID readers to capture the daily movements of trucks passing through three inspection stations en route from Mexico to the United States at the BOTA crossing. The solution, initially developed as a research project funded by the U.S. Department of Transportation's Federal Highway Administration (FHWA), includes TTI software to manage data culled from TransCore RFID interrogators that read a variety of passive RFID tags and protocols, using truck drivers' existing transponders attached to their windshields for toll-payment or shipment clearance identification, to ease the Customs inspection process. This process does not include tracking individuals, but simply collecting an ID number and a timestamp as a transponder passes a reader location. No information regarding trucks, drivers, motor carriers or cargo is collected, says Rajat Rajbhandari, a TTI research engineer.

TTI has also deployed the system at four other U.S. entry points in Texas, Rajbhandari says, with funding provided by the Texas Department of Transportation (DOT). The solution will also be installed in Arizona within the next several months, for that state's Department of Transportation (ADOT).

Approximately 4.7 million trucks cross the U.S. border from Mexico each year, at about a dozen POEs. On average, 25,000 trucks cross the BOTA to El Paso every month. Bottlenecks at this and other border crossings can lead to truck queues extending a mile or longer in length. Therefore, in an effort to improve the accuracy of information used to manage border traffic and reduce delays, FHWA first sought bidders, in 2006, for an automated solution that would determine how long it took for vehicles to pass from Mexico, prior to inspection by Mexican customs, through U.S. federal and state inspections on the Texas side of the border. The system was deployed a year later.

To gain an understanding of the degree of traffic—and when bottlenecks occur—according to time and day of the week, state and federal agencies responsible for processing commercial vehicle traffic crossing the border have often simply collected anecdotal information obtained by having staff members ask truck drivers how long it took to travel from the end of the queue to the CBP primary inspection booths, as well as by visually estimating how far back the trucks have lined up. Using an RFID-based solution, the time required for crossings could be tracked automatically, with the time and date recorded as each vehicle passes key locations. That data could then be utilized to help border-crossing agencies to strategize traffic solutions, such as opening extra lanes at specific times. The agencies could also share the traffic data with trucking companies and product shippers, so that they could schedule drivers to cross the border during times of lower traffic congestion.
According to Rajbhandari, between 50 and 80 percent of trucks passing through the borders are equipped with some type of RFID transponder. The tags have a variety of purposes and origins. As part of the Free and Secure Trade (FAST) program, for example, some freight carriers attach TransCore's eGo passive ultrahigh-frequency (UHF) transponders to their trucks' windshields. The tags, provided by CBP, comply with multiple air-interface protocols, including the American Trucking Associations (ATA) protocol. Similarly, the Texas Department of Public Safety (DPS) is using the passive eGo tags to help identify the trucks passing through its safety-inspection facility.

Thus, in 2007, TTI and Battelle offered Texas DOT a solution using those existing transponders for tracking traffic movement across the BOTA, in order to measure and store data about crossing times for commercial vehicles.

Rajat Rajbhandari, a TTI research engineer

By leveraging the existing vehicle transponders, Rajbhandari determined that a system could be put in place without requiring anything on the part of those traveling across the borders (such as acquiring tags). The research team installed TransCore's Encompass 4 passive UHF RFID readers to capture the unique identifiers of those transponders at two locations. The first reader was installed at a point located approximately 1.5 miles before U.S.-bound trucks reach the Mexican inspection station, where drivers' paperwork is examined by Mexican officers. In this case, the interrogator's location is intended to capture the "worst-case scenario"—that is, the point at which traffic may begin to slow during the heaviest congestion. The second reader location was installed after two inspection processes in Texas (first by CBP, to inspect for unauthorized cargo, and then by DPS, to ensure that each truck meets road-safety requirements). In that way, readers could capture the time it took the vehicle to travel from 1.5 miles prior to the first inspection site, in Mexico, through the final inspection location in the United States.

Readers were installed at the two locations in 2009, each wired to three antennas installed above three lanes. As a vehicle with a TransCore eGo passive tag passes under the reader antenna (active RFID tags, such as those used by some types of toll transponders, can not be read by this system), the reader captures the tag's unique identifier, links it with a timestamp and location data, and then forwards that information to software designed by TTI, residing on a server dedicated for this purpose. In the software, the tag ID numbers are stored anonymously—that is, they are not linked to the identity of the driver or trucking company. When the tag passes the second reader—on the U.S. side of the border, at the point at which trucks exit the inspection station run by DPS—the length of time that has passed since the first read is calculated in the software for that ID number. The software then determines an average crossing time every 15 minutes, based on the travel time of all vehicle transponders, and that data is transmitted to the back-end server via a GPRS cellular connection, and stored there.

The system became operational in July 2009. In August 2010, with additional funding from FHWA and with CBP's approval, TTI and Battelle installed an additional reader at CBP's primary inspection facility, at the same crossing, in order to provide more granular data indicating how long the trucks had to wait after completing the Mexican inspection process, with the reader capturing transponders' IDs as trucks arrived to pass through CBP inspection booths.

The system reads between 600 and 1,000 transponders daily. In most cases, the tags are read at all three locations. In some cases, however, one read might be missed—typically because a vehicle is moving too quickly—in which case, the information is discarded.