Twin Cities' Bus Garages Increase Visibility

The system can pinpoint a bus' location with an accuracy of about 5 feet. A tag's location is calculated by analyzing its signal as received by at least two readers. The master readers come with microcomputers that accomplish the initial location calculation, then send that data to the server, where Ubisense software calculates in which lane and position the bus is located. The software also links the ID number to the vehicle's information, including its size, engine type (such as hybrid electric or standard propulsion), and maintenance history, as well as any other details, such as a need for servicing.

With the new system, Metro Transit's dispatchers need not leave their offices in order to locate buses or assign them out to drivers in the morning. Mechanics use the system to find vehicles quickly when they require servicing, and dispatchers can immediately locate a particular bus within the garage when a passenger calls in regarding a lost item, or if security video footage from a specific vehicle is required. In addition, the system enables Metro Transit to know when each bus leaves a depot, and when it returns, to ensure operator time is being reported properly.

Metro Transit mounted a Ubisense battery-powered RFID tag to roof of each of its buses.

On a computer screen, the Ubisense software displays a floor plan showing the buses' locations and their status—a blue bus icon indicates a particular vehicle originated from a different depot, while a gray icon means a bus has been assigned to a route. A wrench icon signifies the bus requires or is currently receiving repairs. If the user runs the computer mouse over an icon, the system displays details regarding that bus, such as its size and features.

The greatest challenge for Ubisense, Chandler says, was ensuring that readers installed in the ceiling could read the bus tags' RF signals. In the case of lower ceilings, pillars or buses could get in the way of transmission. However, he adds, Ubisense was able to install the readers strategically so that there was no interference.

As the hardware was being installed, Metro Transit also surveyed dispatchers regarding any additional ways in which the system could benefit them, and thus learned that there would also be a benefit to tracking some vehicles parked outside the garage. In this case, Nyberg says, installing additional Ubisense readers would have required added labor and the running of conduit, so instead, the agency chose to use the AVL data in outdoor locations, and to integrate the AVL system into the Ubisense software, thereby allowing dispatchers to go into the Ubisense system and view a list of vehicles parked in outdoor locations.

"It's an efficiency tool for us," Gibbons states, and dispatcher responsibilities are now being reevaluated, as the dispatchers have more time available during their days. "Our guiding principle is valuing innovation and creativity," he says, "and we look for opportunities to improve our services."