Video systems
Introduction
On-vehicle video technology in public transit is becoming prolific thanks to improvements in miniaturization, energy efficiency, and decrease in cost. Video systems can be used for safety and security as a surveillance method. There are also applications in insurance claims management, operator training, and even real-time driving safety as back-up or side-view cameras.
Common Configuration Options
Modern camera systems on transit vehicles save video to specialized hard drives, or "DVR" (Digital Video Recorder), much like those available for television. However, these systems can be configured to save multiple camera views simultaneously. Current technology allows for enormous amounts of storage at a relatively low cost. Operators may be able to choose to save either longer periods of video or increase the image quality. Systems are available in many configurations from a single camera or more than a dozen, depending on the agency's need and budget. Some systems can be combined with GPS technology to tie video to the location of the bus. The camera system can include sensors to automatically tag footage if there is a dramatic change in vehicle movement such as a collision or hard stop, which can be helpful for reviewing accidents or passenger injuries related to panic stops. Typically there is also a single-button operator control which allows the bus driver to tag a period of video if there is an event that might not be otherwise automatically saved. Each manufacturer provides different options and controls for video preservation. Systems are available in which a physical connection is needed to download video, footage is uploaded wirelessly when the bus is in the garage, or is available for limited real-time viewing by a central location.
Exterior View Cameras
Exterior view cameras can be used both retroactively for surveillance and record-keeping or proactively for safe maneuvering. Many manufacturers offer multi-camera systems for both large and small transit vehicles. They can include audio recording, although some states may have laws prohibiting their use.
Side View Cameras
A study in 2013 demonstrated the success of real-time side-view cameras in improving bus operating safety [1]. Testing was done in both closed and live environments using technology which significantly improved visibility covering blind zones on the sides of the buses. A combined mirror-and-video system was found to reduce or eliminate blind spots and was effective at improving side views at night thanks to the infared capability of the cameras.
Rear View Cameras
Rear view cameras are becoming more common on transit vehicles integrated into the dashboard and activated when the transmission is in reverse gear. These cameras can help reduce the risk of collision when backing. They are also available as part of surveillance systems and can be helpful in reviewing collisions, but are less helpful in preventing them.
Interior View Cameras
Interior camera views can be positioned by procurement specification. Common views include entry and exit doors, the passenger cabin, and the operator area. Agencies can use the video to assist with passenger incidents, theft, and to protect operators.
Further Reading
Although rapidly becoming outdated, TCRP Synthesis 38, "Electronic Surveillance Technology on Transit Vehicles," provides basic coverage of how video systems can be configured and used.