1. Field of the Invention
Exemplary embodiments of the present invention relates to an apparatus and method for controlling a traffic light; and, more particularly, to a traffic light control apparatus and method for supporting an emergency vehicle in an emergency.
2. Description of Related Art
A desire to facilitate the movement of human beings has become a motive power to invent and develop faster and more stable vehicles from primitive means to the most advanced airplane. Among the vehicles, the most familiar and popularized vehicle is a car. As the number of cars rapidly increases, controlling cars in a crowded intersection or the like has become necessary. Furthermore, a traffic system has been designed to protect human beings from cars. Such a traffic system has developed into a nationwide network based on traffic lights. To maintain such a traffic system, much research is being conducted on various apparatuses and methods.
In a recent traffic network, one control station may cover a wide area through various types of monitoring devices and control devices for smooth traffic flow. However, when the transportation of firemen, medical workers, policemen, or soldiers and equipments is required because of a sudden fire or accident, there are few efficient solutions. In particular, when a fire truck, an ambulance, or a police car travels in an emergency, the traveling inevitably relies on spontaneous cooperation of other vehicle drivers. In the crowded downtown area, even the cooperation is impossible. As a result, an opportunity of solving an accident in an early stage may be missed.
To solve such a problem, one central control station may control traffic lights to secure a moving path of an emergency vehicle. Hereafter, a method of securing a moving path of an emergency vehicle will be described with reference to accompanying drawings.
FIG. 1 is a configuration diagram of a traffic light control method in an emergency, illustrating a case in which there is no median strip.
In FIG. 1, it is assumed that an emergency vehicle 110 enters from the north to travel to one of the east, the west, and the south. When an emergency occurs, all traffic lights 161, 162, 163, and 164 in an intersection are set to display a red light, that is, a stop signal. Then, the emergency vehicle 110 takes an opposite lane of its traveling direction to enter into the intersection, and passes through the intersection.
FIG. 2 is a configuration diagram of a traffic light control method in an emergency, illustrating a case in which there is a median strip. In FIG. 2, it is assumed that an emergency vehicle 210 enters from the north to travel to one of the east, the west, and the south. FIG. 2 shows the same situation as that of FIG. 1. In FIG. 2, however, since the median strip exists, the emergency vehicle cannot take an opposite lane of its traveling direction. In FIG. 2, two other vehicles 221 and 222 block the way of the emergency vehicle. Therefore, only after the vehicles 221 and 222 pass through the intersection, the emergency vehicle can pass through the intersection. To pass the vehicles 221 and 222, east and west traffic lights 263 and 261 are set to display a red light, and a south traffic light 262 is set to display a green light and a left-turn light. More specifically, the east and west traffic lights 263 and 261 are set to display a red light such that vehicles 231 and 232 traveling from the west and vehicles 251 and 252 traveling from the east are prevented from entering into the intersection. Furthermore, the south traffic light 262 is set to display a green light and a left-turn light such that the emergency vehicle 210 may go straight or make a left or right turn after the vehicles 221 and 222 traveling from the north passes through the intersection. Then, the emergency vehicle can pass through the intersection.
However, when the central control station controls the respective traffic lights depending on the traveling state of the emergency vehicle, huge human and material costs are required in the downtown where accidents occur frequently. Furthermore, when the precision of traffic signal control is decreased to reduce such costs, it may cause unnecessary inconveniences in traveling of vehicles. Accordingly, a signal system which can be properly controlled in an emergency is required.