Ann Arbor, Mich.
Chief Executive Officer
Ann Arbor Transportation Authority
The Ann Arbor Transportation Authority (AATA) is a midsized transit system transporting approximately 6 million annual passengers. Technological advances have been adopted and adapted to enhance the eyes and ears of the transit system in its efforts to improve safety.
Each AATA bus is equipped with eight digital cameras strategically placed to capture images and sound from both inside and outside the vehicle. These cameras are programmed to capture four frames per second (they are capable of recording up to 30 fps) with both their images and the accompanying sound being recorded and stored for up to a week. Questionable activities occurring either on or near a bus are recorded for later review. When alerted by drivers, passengers or the public, these images are downloaded for viewing and further processing by AATA officials or law enforcement agencies.
Digitally recorded images and sound can be transmitted instantly via the Internet to law enforcement agencies, insurance companies or other interested parties. In their original security-encrypted state, the images cannot be altered, thus guaranteeing a valid “chain of custody.” These images can, however, be copied and reformatted for enhancement purposes. They can be lightened, images can be sharpened, specific portions of an image can be enlarged — all to increase their clarity and usefulness.
Digital cameras that do not include audio capabilities are strategically located in and around all facilities. Images are fed live into an array of storage hard drives providing approximately 15 terra-bytes per facility location. These hard drives enable AATA to store about a month of activity gathered by all cameras.
Live images are available for viewing at several locations throughout AATA’s facilities while being simultaneously recorded. These Internet protocol cameras are high-resolution megapixel devices with “smart” irises and infrared capabilities for night vision. The system includes numerous pan-tilt-zoom cameras that can be programmed to a specific pattern or can sweep at random.
All AATA vehicles are equipped with a GPS-based advanced operating system (AOS) that integrates multiple technologies into one computer-controlled system using three separate radio frequencies to constantly monitor numerous activities associated with each vehicle. In addition to keeping the maintenance department constantly apprised of the status of a vehicle’s engine and transmission, the system is in constant communication with the transportation department’s control center, which monitors the speed and location of each vehicle, and the IT department, which monitors passenger data.
Having a vehicle’s precise location, direction and speed displayed on video monitors in real time is crucial to first-responders in any emergency situation. The AOS system has a number of both audio and visual alarms that alert the control center to departures from the vehicle’s normally scheduled activities or operating parameters.
The AOS system integrates and manages the voice and text communication system onboard each vehicle. Voice communications are normally transmitted using a hand-held telephone-type receiver so that passengers are generally unaware of discussions between the control center and each driver. Emergency communications are available in the event of system disruptions or power failures.
Each driver has access to a covert alarm which silently turns on microphones inside the bus so that activities can be monitored at the control center. In this mode, there is no direct communication between the control center and the driver. There is also an overt alarm which a driver can trigger for immediate priority communication with the control center. In this mode, the dispatcher responds by voice immediately to the driver.
Communication is considered an important element in the safety of passengers, employees and the public, calling for a certain level of redundancy in voice communication systems.
Although voice communications are integrated into the AOS system, which normally operates as a “closed” system, in the event of an AOS failure, the default voice system becomes an “open” system enabling the control center to communicate with all buses at the same time.
AATA maintains a large number of hand-held radios that bolster communication between buses and the control center. These units are used in the rare case of a complete failure in the AOS radio system (such as tower failure). As a last resort, drivers are allowed to utilize their personal cell phones (following mandated safety protocols) to maintain communication with the control center.