Self-Algorithm Traffic Light Controllers for Heavily Congested Urban Route

Traffic lights are commonly known as the stop light or stop-and-go lights used as a source of signaling device in junctions around the world. It is common to position traffic lights on a certain road intersections, pedestrian crossings and other locations to control competing flows of traffic in order to enhance the smoothness of traffic flow. Traffic lights have been installed in most cities around the world regardless of different standards set by the local authorities. Traffic light controllers is programmed to assign timely directions for road users by demand in the form of colors which is Red, Amber and Green. Even though traffic lights are known as the best device in controlling traffic flow for road users, yet accidents reported at the traffic junction is very common. There are 2 methods in controlling the traffic light system placed on a certain junction. The most common one is the sequencing method, whereby the traffic light system is designed to operate according to the preprogrammed sequence without any consideration of real time behavior. The second method is the demand based controller which response to the preprogrammed timer based on real time sensor detection on a certain road junction. With both method widely used around the world, surety on traffic flow smoothness is not established. When authorities talk about efficiency and accuracy on real time traffic flow control, there are always room for further enhancement especially on the controlling and sensing method. In the afford to provide a solution for such miseries, a novel implementation of sensing method which will be incorporated with self conditioning program will be a practical solution. The new sensing method is capable of counting the total number of vehicles entering a certain junction and exiting from a certain junction on real time basis. Based on this detection, the programmable logic controller will trigger the traffic light indicators according to real demand. The new method should also be easy for further enchantment of traffic light system in ensuring smoothness of traffic flow especially during peak hours. Key-Words: -Traffic Light System, self-algorithm traffic light, multiple junction traffic light, metal detector, programmable logic controller. 1 The traffic scenario Nowadays, vehicles have rapidly increasing throughout the world, particularly in large urban areas [1]. Therefore the need arises for a simulating and optimizing system for the traffic controllers to better accommodate this increasing demand by road users around the world [1]. Traffic lights are commonly used device to regulate roadway intersection traffic with a view to both safety and smoothness of vehicle flow [2] for generations where it is still considered the best practices. Since the traffic light was invented ages ago, there were significant revolution have been down in various aspects of it. The most common revelation which we can visualize is the displays of traffic light itself. The other revolution which is being enhanced and improved is the traffic light controllers. The need to improve the efficiency of the controller plays an important role as the increasing number of vehicles in the road is tremendously in a large amount. There are a lot of benefits to improve the traffic flow. Many road users reclaimed that by improve WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS S. K. Subramaniam, M. Esro, F. L. Aw E-ISSN: 2224-266X 115 Issue 4, Volume 11, April 2012 the traffic flow can enhance their quality of life and less traffic congestion and therefore reduce the possibility of accidents and saving the life. Apart from that, the drivers can make most of it thru saving in terms of fuel consumption. As the traffic build up at a certain intersection, vehicles have to crawl in and out of the junction most of the time. Furthermore, time spent by drivers traveling to and from work is not time spent doing work [3]. In fact, most people are essentially constrained to perform only the task of driving as they commute [3]. Goods must transport and service providers must travel to their clients as planned [3]. Clearly, traffic delays impinge on their productivity and economic efficiency regardless of their location [3]. Another factor which is always interrelated with traffic light is the pollution issue. As the number of road users constantly increases, those vehicles waiting in the traffic light junction will generally produce greenhouse gases such as carbon dioxide, carbon monoxide etc. This directly contributes towards the air pollution issues since it’s an ongoing activity through the year. One of a congested road is shown in Fig. 1. Some of the road users are wearing mask in the afford to preventing them to inhale the carbon dioxide fumes. Fig. 1: Motorist queuing in a certain road during peak hours. The fumes generated by vehicles are impossible to be eliminated in roads, but it will be possible to reduce if better traffic flow is established in the city roads. Such fumes are not only dangerous but it will affect the eco system of the world in the long run. The example of vehicles generating fumes is as shown in Fig. 2. Fig. 2: Greenhouse gases produce by vehicle during peak traffic hours 2 Limitation of the conventional technology The conventional traffic light system is build with only one sensor placed at the road end before the junction. The sensor is usually visible as a black rectangular line as shown in Fig. 3. Fig. 3: The magnetic loop sensor placed at the road end before the junction. WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS S. K. Subramaniam, M. Esro, F. L. Aw E-ISSN: 2224-266X 116 Issue 4, Volume 11, April 2012 The usage of one sensor is not practical for all applications. Such a practice creates an inefficiency system because with only one sensor to detect the presence of a vehicle approaching the road end. If the sensor is activated, a signal will be send to the traffic light controller to notify the availability of the vehicle. In the case of the sensor malfunction or faulty, the traffic light control system will operate in a pre programmed mode while the presence of a vehicle could not be detected at all time. In big cities, traffic flow is high especially during peak hours [4, 5]. It is quite common for the traffic police to arrange the traffic flow as shown in Fig. 4. During the usage of a traffic police, the road users will be confused by the traffic light indicators as well as the direction given by the traffic police. I such scenario, the risk of traffic police increases when standing in the middle of the traffic light intersection which may lead to the accident in the traffic light junction. Fig. 4: Traffic police arranging the traffic flow in Malaysia During peak hours the traffic police will be present at the traffic light junctions to direct the traffic to ensure smoothness to the road users. The traffic police will be at the center of the junction and give direction to the road users and at the same time the traffic light will operation as programmed. In most cases, the road users will concentrate on the traffic light sequence from a distance away and it is to their priority. Some confused driver will end up in an unexpected accident with other drivers in the same lane and there are many cases report on accidents which involve traffic police as a result of confusion to the drivers. The inefficiency of conventional traffic light system leads to traffic congestion that occurred every day. Fig. 5 shows that an old lady pass through the traffic junction while a volume of vehicles are waiting the traffic light. Such a scenario is very common in the city roads especially during peak hours. Fig. 5: Traffic light junction during peak hours Traffic flow during peak hour is difficult to be predicted and it’s not an easy task to control especially when the number of vehicles is beyond the capacity. In some worse cases, the road user will tend bypass the traffic regulation due to long queers and long waiting hours. A situation of traffic congestion in a city is shown in Fig. 6. WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS S. K. Subramaniam, M. Esro, F. L. Aw E-ISSN: 2224-266X 117 Issue 4, Volume 11, April 2012 Fig. 6: Traffic congestion in a city 3 Traffic light controller The traffic system requires a stable controller to operate at all times. The common technology behind the traffic light controllers are programmable logic controllers (PLC). The PLC is an intelligent device which is capable to work without human interventions at all times regardless of duration and weather conditions [4, 5]. For generation PLC is being used as the heart of the traffic light system. The traffic light sequence is preprogrammed in the PLC for the display of the traffic light indicators. The PLC controllers are reliable and durable for such an application especially into extensive automated operations. There are even some sophisticated controllers used for traffic light controlling. The computer based controllers are at certain traffic light junctions to operate with some intelligent. The problem with computer based controllers is the cost and the durability of the system. The computer based system requires additional supporting components due to the use of high voltage and current for the display system [6]. As many new technologies are being explored within the resources of traffic light controllers, the best practice is the PLC. With new technological PLC available in the market, intelligence is added to its conventional operations to make it even more efficient. Such an approach is always an ongoing process in ensuring the smoothness of the traffic flow. As the most of the controllers are common, it limits the capability of the operation during peak hours. 4 Traffic light programming methods There are two methods in programming the traffic light controllers placed on a certain junctions. The most common method is sequencing method, whereby the traffic light system is designed to operate according to a pre-programmed sequence without any consideration of real time behaviour. The second method is sensor based controller which response to the pre-programmed timer based on current demand on a certain road junction.