Detection of vehicle occupants in HOV lanes: exploration of image sensing for detection of vehicle occupants

One technique to better utilize existing roadway infrastructure is the use of HOV and HOT lanes. Technology to monitor the use of these lanes would assist managers and planners in efficient roadway operation. There are no available occupancy detection systems that perform at acceptable levels of accuracy in permanent field installations. The main goal of this research effort is to assess the possibility of determining passenger use with imaging technology. This is especially challenging because of recent changes in the glass types used by car manufacturers to reduce the solar heat load on the vehicles. We describe in this research a system to use multi-plane imaging with appropriate wavelength selection for sensing passengers in the front and rear seats of vehicles travelling in HOV/HOT lanes. The process of determining the geometric relationships needed, the choice of illumination wavelengths, and the appropriate sensors are described, taking into account driver safety considerations. The paper will also cover the design and implementation of the software for performing the window detection and people counting utilizing both image processing and machine learning techniques. The integration of the final system prototype will be described along with the performance of the system operating at a representative location.