This study applies the image analysis technique to detect left-turning vehicles at intersections. The problems existing in the current method of left-turn data collection are discussed. An optical image device system including a CCD video camera, an interface board, an image monitor, and an ibm pc/at was used. An algorithm with linear time complexity was developed for detecting left-turning movements at intersections. Microcomputer software was derived for the algorithm. This computer system is a real time system. The accuracy of the algorithm is about 80% for detecting the left-turning vehicles whose signal lights are on. This study so far has had only limited success. The difficulties of attaining greater accuracy as well as the possibilities of improving the developed image analysis system are also discussed.
Samenvatting