Commuters using two newly built bus and subway transit terminals in the Montreal suburb of Laval won’t need to worry about frostbite as they wait for busses during cold winters, thanks to an RFID-system deployed by the city’s Agence Métropolitaine de Transport (Metropolitan Transport Agency).
RFID interrogators mounted on lampposts at terminal entrances read the unique ID numbers of passive EPC Gen 2 ultrahigh-frequency (UHF) tags attached to the busses (on a side window), then send the tag IDs, along with a timestamp of the read event, to a server inside each station. Every tag ID number is associated with its respective bus’s route information in the agency’s database. The server uses the RFID data to determine that a bus is approaching its designated terminal dock, and displays this information on digital screens within the terminal to alert commuters, giving them ample time to walk out to the dock and board the bus.
The system has been well received by Laval residents, says Pierre Malboeuf, president of Eminencia, the RFID systems integrator on the project and a presenter at last week’s RFID Journal LIVE! Canada 2007 conference, where he explained the system to attendees. According to Malboeuf, some residents say they would not likely use bus services at the transit hubs—which also include subway stations offering service to Montreal—if not for the ability to wait for their buses inside the terminal rather than outside.
The RFID system also helps improve overall bus service and operations at the two stations, Malboeuf says, because it provides terminal operators with visibility they would not otherwise have since they cannot view all bus docks from where they sit. Thanks to the RFID system, they can now use a station map on a computer monitor at their desks that shows every bus as it arrives and departs from the terminal.
On a separate computer screen, each dispatcher can monitor a list of bus schedules showing the expected arrival and departure times for every bus throughout the day. In the past, a dispatcher might not have realized a bus was running late unless the driver called to indicate a delay. With the RFID bus-monitoring system, however, the dispatcher need not wait for the driver’s report before deciding to dispatch another bus and driver to keep a specific line on schedule.
Before deploying the RFID system in April, the transport agency worked with Eminencia to compare the use of passive RFID tags against other technology options, including infrared tags and readers, as well as active RFID tags combined with GPS receivers. Infrared indicators, however, would have required a clear line of sight between the bus and interrogator, and there was no way to ensure this happened each time a bus approached a terminal or its dock landing. Active GPS-enabled RFID tags would have given very precise location data, but Malboeuf says such an option was cost-prohibitive .
In addition to mounting Motorola EPC Gen 2 readers on lampposts near the station entrances, the agency is also installing interrogators along the bus docks. The readers are installed inside existing utility boxes, at the center of each dock (buses approach either side of a dock), and up to four antennas are wired from the reader (two on each side), so they are positioned closer to where each bus approaches its dock.
The agency is using Motorola’s EPC Gen 2-compliant UHF passive weatherproof Cargo tags, mounted on a right-side window of each of the 400 buses serving the two transit terminals. The tags are positioned such that as a bus stops at the dock, its tag is close to the reader antenna. The antennas mounted at the station entrances have a 15-foot read range, similar to the range of the dock-mounted antennas. However, Malboeuf says, the power levels and orientation of the dock antennas needed to be optimized so they read only the area directly in front of them, and not the IDs of tags on buses at adjacent docks.
The tags are adhered to the windows with double-sided 3M tape, certified as being able to withstand high-power bus wash cycles and temperatures ranging from -40 to +40 degrees Celsius, as well as with ice and high moisture and humidity.
The interrogators mounted along the dock were easily added to the local area network at each station via Ethernet cables. To collect tag data from those mounted at the station entrances, however, Eminencia installed Motorola Wi-Fi access points on the building’s exterior, as close to the entrances as possible, then installed Wi-Fi signal extenders at each location, so that the readers could transmit their data, via integrated Wi-Fi radios, to the servers over a wireless link, Malboeuf says.
In the future, he notes, the transport agency hopes to extend its RFID infrastructure by adding Motorola readers (along with Internet connectivity) to utility posts throughout the streets the buses service, so it can monitor their location en route. It also intends to work with the city’s transportation department so the readers will trigger changes in the traffic lights to favor the movement of buses through intersections.