Office of Operations Freight Management and Operations

Measuring Border Delay and Crossing Times at the US–Mexico Border
Final Report
Automated Crossing and Wait Time Measurement

CHAPTER 10: SUMMARY AND CONCLUSIONS

General Conclusions

An RFID technology based system using passive transponders was put into real-world operation in the vicinity of the BOTA at El Paso, Texas–Ciudad Juárez, Mexico and Pharr-Reynosa International Bridge, Pharr. The RFID system was designed to automatically measure, display, and archive information on wait and crossing times of US-bound commercial vehicles transiting the POE. This pilot system was the result of years of FHWA efforts that laid the groundwork for its implementation. Development of the system followed a systems engineering process with significant upfront and continuing stakeholder involvement. Stakeholders were informed that there was neither intent nor capability for collecting information on identification of driver, vehicle, or carrier as part of the system design. The only information to be collected by the system was the ID number for the windshield transponder, a timestamp for when it was detected passing a RFID read above its lane, and the designation of the reader location. The presence of the equipment and its operation appear to have been fully accepted by the motor carriers, their drivers, and all other stakeholders.

Development of the system followed a systems engineering process with significant upfront and continuing stakeholder involvement. Stakeholders were informed that there was neither intent nor capability for collecting information on identification of driver, vehicle, or carrier as part of the system design. The only information to be collected by the system was the ID number for the windshield transponder, a timestamp for when it was detected passing a RFID read above its lane, and the designation of the reader location. The presence of the equipment and its operation appear to have been fully accepted by the motor carriers, their drivers, and all other stakeholders.

Following system design, development, equipment procurement, bench testing, installation, integration and checkout, and test and evaluation, the RFID system became operational in a real-world environment on July 8, 2009. Its two initial reader stations utilized solar panels with batteries, as reliable hardwired power was not available at either of the two RFID reader stations. The reader stations communicated with a server via wireless (cellular) communications. The system was programmed to cease data collection during days and periods of days when there were no crossing operations. Crossing time data were collected and archived over a nearly 33-month period and were analyzed for trends and anomalies. That analysis is contained within this report.

While the system was originally envisioned and developed for automatically measuring crossing times, it was subsequently desired that wait time data also be collected. To enable that, meetings and agreements between FHWA and CBP were conducted that resulted in CBP and GSA approval for a RFID reader station at the CBP Primary Inspection for both BOTA and the Pharr-Reynosa POEs. A comparability test was successfully conducted to ensure the RFID wait time RFID installation at CBP primary inspection booths would not interfere with CBP equipment. Installation of RFID reader stations for wait time measurement was conducted in March 2011 for the Pharr-Reynosa POE and April 2011 for the BOTA. Operations at the BOTA and Pharr-Reynosa POEs demonstrated that crossing times and wait times can be automatically and accurately measured using RFID technology. Experience from the engineering process followed and lesson learned were used to prepare a number of guidance and instructional documents for use by future deployers of these systems.

Wait and crossing time of US-bound trucks at both ports of entry are being continuously collected and archived by TTI. The data collected from the field are filtered and converted into individual wait and crossing times and subsequently aggregated into 15-minute, hourly, daily, and monthly averages. The research team was also tasked to develop a prototype web tool to disseminate most recent wait and crossing times of trucks at both ports of entry. Methods of dissemination include publicly available Web site and RSS feeds. The research team also developed an application, which monitors the RFID system’s health and fidelity in near real-time. This has helped the team to identify problems within a small window of time and fix them quickly.

Lastly, a November 21, 2011 article in the publication RFID Journal (http://www.rfidjournal.com/article/print/8984) titled “RFID Readers Installed at US-Mexican Bridges to Help Ease Traffic Congestion” described the travel time measurement system at BOTA. The article noted that since the BOTA implementation, a number of other POEs along the US‒Mexico border in Texas and Arizona have implemented RFID-based travel time measurement systems or were in the process of doing so (currently a total of 6 POEs in addition to BOTA).

Reliability and Maintainability

During the nearly 33-month period of this report when the system collected and measured crossing time data under real-world conditions, the RFID equipment operated without damage, interruption, or the need for any equipment replacement, recurring or non-recurring maintenance. It operated in hot, arid, dusty conditions with vibration from passing trucks. Connectivity through the wireless modem was good.

Lessons Learned

  • The RFID system is a successful implementation. It was developed using a systems engineering process. Its test and evaluation following installation showed the system performs to expectations and its data are accurate. The system has performed reliably since being placed into real-world operation without damage or major maintenance.
  • The processed data showing near real-time average wait and crossing time measurements have been made available to stakeholders through web access. The display is both user-friendly and useful.
  • It is essential to have a skilled bi-lingual, bi-cultural facilitator to conduct stakeholder meetings and to contact Mexican stakeholders for projects on the southern border. A bi-cultural facilitator would also be helpful on the northern border.
  • Stakeholder involvement is very important. It not only informs all interested parties as to what is intended and when, it explains why and gets their buy-in and continuing support. This can help in a number of ways such as a vehicle operator reporting damaged equipment, notification to system operators of pending events (such as construction) that will affect operation of the system, and greater use of the system for logistics efficiencies.
  • Construction or traffic diversion can have a profound effect on the performance of the system. Through early stakeholder involvement, it was discovered that roadway construction was planned at a site that was originally intended for the first (R1) reader just upstream from the queue on the Mexico side. Without that advance knowledge, equipment might have been installed where it would have risked being damaged by ongoing roadway construction and even might have had to be moved – an unplanned and expensive development.
  • It is critical to make sure that there is adequate signal strength for cellular modem to transmit data from field devices to a server. This should be done well in advance to the actual deployment and can be accomplished simply by reading the signal strength from a mobile phone.
  • RSS has proven to be an extremely cost-effective method to share near real-time data with individual users, news media, traffic management centers, etc. RSS includes a standardized XML file format containing information to be published once and viewed by many different programs. The user subscribes to a feed by entering into the reader the feed’s URL or by clicking an RSS icon in a web browser that initiates the subscription process. The RSS reader checks the user’s subscribed feeds regularly for new work, downloads any updates that it finds, and provides a user interface to monitor and read the feeds. RSS formats are specified using XML, a generic specification for the creation of data formats. RSS feeds can be read using software called an “RSS reader,” “feed reader,” or “aggregator,” or even the latest versions of commercially available web browsers, which can be web-based, desktop-based, or mobile-device-based.
  • Even though there was knowledge of local construction plans that allowed the R1 reader station to be located in an undisturbed location, there was a subsequent expansion of lanes abreast of the R1 station (from four to seven lanes), coupled with signage redirecting trucks to the far side of the road from where the active antennas were located. These combined factors had the effect of decreasing the number of tag reads on the Mexico side for the last half of the nearly 14-month initial data collection period. That decrease affected the sample size (i.e., the number of matched tags) for the crossing time measurement. The problem was solved by relocating the RFID reader station to a gantry a short distance downstream from the original location where trucks were exiting to cross BOTA.
  • There was a set of RFID antennae installed by the DPS for a different need on a crossbar in close proximity to this project’s R2 reader station crossbar at the BSIF exit on the US side. In November 2009, around the time of that close-by installation, it was noted that the number of tags read by the R2 reader dropped dramatically. While it was never demonstrated that there was frequency interference, remote adjustments were made that changed the R2 station from the original setting of 915 MHz to new frequency 902.5 MHz. This increased the sample size compared to previous months. Thus, a lesson learned is that RFID frequencies can be adjusted without decrease in performance. In retrospect, (1) closer stakeholder coordination might have been able to result in greater spacing between the two crossbars, and (2) when the problem occurred, an onsite spectrum analysis might have conclusively determined that frequency interference was the cause.
  • Having additional reader stations to segment the vehicle crossing path is desirable. By having more segments, border crossing operators and other stakeholders are better able to see where delays are occurring that affect the entire crossing. The more reader stations, the better delays can be isolated and dealt with in a timely manner.
  • Import duties may have to be paid on equipment brought into Mexico.
  • Stakeholder input in development of information dissemination techniques is important. Different stakeholders have different perspectives in how and what kind of information they would like to receive. For example, carriers see more value in real-time information (e.g., most recent wait and crossing times), while MPOs and trade groups value historic information.

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