Automatic Passenger Counters (APCs) are the devices that count the passengers entering and exiting the transit vehicle. In early times, transit agencies use ride checkers to count the passengers on board. Later on, advance technologies in counting the passengers while boarding and alighting makes the work easy for transit agencies. These technologies eliminate the manual error in counting the passengers.
APC technologies typically include treadle mats, horizontal or vertical infrared beams, passive thermal, digital cameras or thermal imaging, ultrasound, light beams, computer vision 3d, etc. Treadle mats count by sensing the pressure of people’s feat as they traverse the bus steps. Infrared beams are mounted either horizontally or vertically and directed across the path of boarding and alighting passengers, counting riders when they pass the beam. When a human goes into the field of view of a passive thermal detector, there is first a reduction of the background caused by the person's opacity and secondly a new source of radiation as the human enters the field. Since the body temperature is usually higher than the surrounding environment, the result is an increase in the infrared light captured by the detector. In short, it looks at the temperature difference between a human and his background.
Camera-based counting systems image the entrance or part of the entrance. The sequence of images is analyzed using software to identify people and track their movement. Many visually-based sensor systems rely primarily on a technology that is equipped with a single camera as a central element. The disadvantage of this two-dimensional imaging technology is derived from a relative inaccuracy of the image capture. For variable light conditions, with shadows or objects that may overlap in perspective occur such as irritation in the data analysis. A single eye sees just not sharp enough. 3D-Sense technology is based on the stereo camera principle. This is not only inspired by the human visual perception, but also their equal. Two eyes are working very effectively in all situations that require increased attention. 3D technology Sense Toolkit combines stereoscopic cameras with other hardware and software components to intelligent systems that capture and process visual information in three dimensions.
An eleAn electronic record is created at each stop which typically includes stop location, date and time of bus stopping, time of doors opening and closing, number of passengers boarding and alighting and passenger load. These records are grouped by trip, and usually held in storage on the vehicle for a time, until they are downloaded to a central facility for further processing and use. The data can be downloaded manually or automatically. Manual data download requires a person to download the data to a disk. By equipping the vehicle with an RF or optical modem, the APC system can automatically connect with an external computer and download the APC data without human intervention.