Traffic Signal Control System Essay Example

1Traffic Light System

Traffic Signal Control System

Table of Contents

3Background Information 1.

4Selection of the System 2.

4Characterization of System under Study 3.

4Systems Objectives/Purpose a.

6Environment b.

7Sub-Systems Objectives/Purpose c.

10Elements of the Sub-Systems and their Attributes d.

10System Relationships 4.

10System: Between Each of its Sub-Systems a.

11Sub-System: Between Each of its Elements b.

12System Complexity 5.

12Dynamics of System 6.

12Part 2:

12Problem/Challenge Identification 1.

13Problem Context 2.

13Stakeholders/Players 3.

13Selection of System Methodology: Hard versus Soft Systems Methodologies 4.

14Application of System Methodology 5.

14systems methodologyBrief description of the a.

14Soft Systems Methodology b.

16Implementation Issues 6.

16Conclusion 7.


Part 1:

  1. Background Information

A system is «A complex whole, set of connected things or parts, organized body of material or immaterial things». (Oxford University Press, 1989). Traffic engineering remains an areas within transportation engineering that deals with effectiveness and efficiency in dealing with safe, adequate planning, traffic operations, and geometric design of highways, superhighways, streets, as well as their terminals, networks, as well as the abutting land relationships that have a control over other motorized and non-motorized modes of transport (Sundar, 2015). The constraints of constructing new road infrastructure impose higher performance expectations upon the deployed traffic control and management systems. In essence, traffic control signals can be considered as vital elements of traffic management. They are directly correlated to excellent mobility, environmental, and safety parameters in the precincts of transportation networks. It is for this reason that transportation agencies are increasingly incorporating the used of signals in intersections. However, to ensure that there is effective use of the signals, the traffic signals, which are mostly used as traffic lights have to be incorporated into a traffic-signal control system to ensure that they work effectively and optimally.

Changes in traffic patterns and demands on the transportation networks are increasingly leading to instances of poor environmental, operational, and safety parameters of a traffic light system. However, these failure instances can be attributed to obsolete technology. As such, it is paramount that the government department concerned with transportation implements technology that is up-to-date so as to promote the traffic light system’s effectiveness and efficiency while eliminating, mitigating, or diminishing instances of failure. For this reason, traffic engineers need to strive to take into consideration numerous aspects so as to improve the performance of the traffic signal or lighting system. Some of the factors that need to be taken into account include geometric constraints and human factors, but, a critical component that needs to be considered in a traffic-signal control system is the control equipment. The control element ensures that the operability of the signals is optimized and work within the allowable limits. Urban traffic control remains one of the areas of traffic engineering that deals with efficient and safe operations of road and transportation networks within the city road networks.

  1. Selection of the System

Systems are the backbones for running everyday business structures (Nicholas, 2004). Traffic signal control system is a component of Intelligent Transportation Systems (ITS) and aims at providing practical help for the traffic engineering community through a multimodal and integrated environment. In essence, ITS can be considered as the application of managerial strategies and technologies for the sole purpose of increasing safety and efficiency of surface transportation, which may include national, regional, as well as local applications. On the other hand, a traffic control system provides traffic control via traffic management strategies that are responsive to aspects of changing traffic demand, as well as benefitting the public with an improved, effective, and efficient traffic flow. For this reason, a traffic signal control system is important especially in urban areas where movement of vehicles in the streets is hampered by traffic jams. The system is effective in managing free flow of vehicles and pedestrians.

  1. Characterization of System under Study

  1. Systems Objectives/Purpose

The purpose of the traffic signal control or traffic lighting system is to ensure the provision of surveillance, control, and maintenance functions (Henderson and Aravind, 2015). These include controlling traffic by adjusting and coordinating the various traffic lights or signals at roundabouts, junctions, and intersections. In addition, the system ensures that there is surveillance by monitoring the changing traffic conditions using vehicle cameras and detectors. It also ensures that there is effective maintenance so as to service the traffic demand, sharing traffic status along with other agencies, as well as ensuring that the traveling public also uses the road networks with a significant safety standards, and also operating and maintaining the traffic signal control system.

As such, the objective of the traffic lighting or signal system is to control and coordinate the traffic signals and to ensure that the traffic is well monitored and surveilled. In essence, the traffic light or signals control the signal timing at specific signal controllers thereby working to effectively coordinating and controlling surface traffic flow. Also, it is vital to stress that for advanced system, the traffic flow information can be used as input data particularly by incorporating algorithms in the traffic control programs used (Sundar, 2015). These can in turn automatically adjust the timing plans for signals and lighting signs, thereby automatically responding to the current traffic demands. It is an effective method of controlling traffic, and thus, it should be incorporated by travel agencies owing to its efficiency because it cuts down manpower while providing an element of effectiveness and efficiency. On the other hand, monitoring and surveillance of the traffic can be used to monitor traffic flow and provide real-time surveillance on what is happening on the roads. This objective is realized by using detection devices, and one of the most used ones currently is the inductive loop vehicle sensor. In addition, other technologies that are currently being adopted by numerous transportation agencies include the close-circuit television, which is mostly known as CCTV cameras. These cameras have an image processing capability to derive actual data about traffic flow, thereby enabling traffic managers to monitor the various videos for surveillance purposes. As a matter of fact, information gathered via this method is mainly used for determining the prevailing road conditions, thereby identifying and verifying the various incidents that are happening on the road. In addition, this information can also be used in verifying traffic information that has been collected via other methods.

Another objective of the traffic control system is monitoring malfunctions. It is important to point out that effective traffic light control system should be able to monitor the various faults and malfunctions that the system may have, and in turn, correcting them so as to ensure that the operability of the system is at its maximum. The advantage is clear, to ensure that the traffic flow is properly controlled, thus preventing instances of failure that may lead to accidents. The objective mainly is to identify operational problems and taking appropriate rectification measures to return the equipment to its proper operating condition.

As such, the main goal of the traffic lighting system is to maximize the traffic flow effectiveness and efficiency thereby ensuring public safety. Also, it aims to monitor traffic flows and take the necessary and appropriate control decision s that will ensure that there is the free flow of vehicles. By decreasing the travel time, vehicle stops, fuel consumption, and carbon emissions, and delays, while also increasing the travel speed, these systems will ensure that the transport sector does not have an adverse environmental impact.

  1. Environment

The system operates mainly in paces with an extensive traffic flow, especially in the urban areas. In essence, any place that requires the regulation of traffic control needs an effective traffic signal control system (Henderson and Aravind, 2015). In addition, the system is also advantageous as far as matters of environmental protection are concerned. In essence, the lesser time the vehicles utilize, the less the amount of gas the vehicles use, hence minimal greenhouse gas emissions (Henderson and Aravind, 2015). For this reason, the system once implemented is a positive move towards the environment by serving as a strategic move towards environmental protection. Also, it can be pointed out that the system in most instances is controlled by governmental agencies. The operability requires that the transportation agency to operate remotely through serve and client networks. For this reason, the system is environmentally sound, and thus, it provides a foundation to compete in a global economy by providing a mechanism for efficiently moving people and goods.

  1. Sub-Systems Objectives/Purpose

The traffic light/signal system is encompassed by several subsystem. The following diagram shows the main subsystems of an Intelligent Transport System as white rectangles.

Traffic Signal Control System

Figure 1. Subsystems (white rectangles), communication links (white ovals). Source: Henderson and Aravind (2015).

From the ITS subsystems, there are various subsystems that can be derived to feature the traffic light system. These are transit management, information service provider, planning, fleet and freight management, and traffic management subsystems in the centers physical elements. On the roadside physical elements, roadway and commercial vehicle check can be considered as the main subsystems in the roadside physical element. On the other hand, commercial, transit, and vehicle are the main subsystem in the vehicles’ physical element.

The information service provider subsystem is involved in collecting, processing, storing, and disseminating transportation information to the system operators, as well as the traveling public (Henderson and Aravind, 2015). The objective is to collect data, fuse, and repackage it, as well as collecting information from the transportation network, and thus, redistributing the information to the users of such information in the transportation network. In essence through Information Service Providers, the traffic light system can be controlled effectively by ensuring that the right information about traffic flow is acquired, and thus, appropriate decisions can be made on how to control the traffic signals to effectively and efficient control traffic flow.

The transit management subsystem’s purpose is managing transit vehicle fleets and thereby coordinating it with other transportation services. It is involved in maintaining and ensuring smooth flow of traffic operations, as well as providing information about individual vehicles. It is particularly important in providing real-time incident data from the traffic management subsystem. On the other hand, the traffic management subsystem is paramount in ensuring that there is effective and efficient flow of vehicles in the road networks. It ensures that traffic is well managed and that there is seamless control of vehicle flow in the roads. For this reason, the traffic management subsystem is important in providing real-time information that can be used in making decisions on what intersections or road junctions need to be temporarily closed or opened to allow or stop the movement of vehicles. The planning subsystem is mainly important in providing insight on how to better traffic control in all the road networks so that there is a better and planned control. Ideally, planning ensures that no road networks are underutilized or over utilized thereby providing efficient use of the resources. The fleet and freight management subsystem is used to provide fleet or freight management managers with real-time information about their equipment (Henderson and Aravind, 2015).

The roadside elements include signals that show which parking space is vacant, and therefore enabling effective parking for vehicles. This falls within the parking management subsystem. In essence, this subsystem will ensure that drivers are not stranded in finding parking spaces, and thus, it eases the process. The roadway subsystem is mainly encompassed of equipment placed along the roadway that control and monitors traffic. For instance, CCTV cameras among other image processing systems are important in augmenting traffic signals as they provide real-time surveillance. They also include grade crossing warning systems, as well as freeway ramp metering systems that low effective control of the traffic lights (Henderson and Aravind, 2015). In addition, there need to be traffic lights on the roadside that can effectively signal drivers and pedestrians on when to proceed, stop, or wait. By doing this, safety on the roads is guaranteed. Commercial vehicle check subsystem is important in supporting automated vehicle identification, particularly on mainline speeds that can be used in credential checking, as well as roadside safety inspections. They can also check historical data, thereby, they can provide warnings to commercial vehicle motorists, proper authorities, as well as the fleet managers.

Commercial subsystem mainly is composed of commercial vehicles in the road. The transit subsystem can also be considered as the system which provides processing, sensory, as well as communication functions thereby supporting efficient movement of passenger. Lastly, the vehicle subsystem encompasses all types of vehicles available in the road, and thus, it enables the transportation agency to keep the inventory of vehicles I the road, which therefore leads to effective planning and making future decisions.

  1. Elements of the Sub-Systems and their Attributes

Elements encompass what a system is made of (Blanchard, 2004). The elements of these subsystems are vehicles, roads, travelers, centers, and roadside signs. The vehicles could be huge tracks or small vehicles. There are different automobiles design but all fit into this category. Small vehicles can include taxis or personal cars but for the case of huge tracks, these may include construction lorries or vehicles that transport heavy machinery. Travelers can be composed of the motorists who are involved in moving the vehicles, as well as other road users, such as pedestrians. Centers include those agencies that provide actual or real-time information. Also, they include agencies that maintain the systems and those involved in ensuring that the traffic light system is optimally working.

  1. System Relationships

  1. System: Between Each of its Sub-Systems

As Eisner (2002) points out, there exists a direct relationship between subsystems and the systems. The traffic light system is related to the subsystems in that these subsystems ensure effective and optimal operability of the system. For instance, information service provider is important in providing traffic information. Fleet and freight management subsystem is important in managing the fleet. The roadway subsystem is important in guiding the vehicle subsystem as it ensures that the right signals are provided and appropriate steps are taken. The transit and traffic management subsystems ensure that there is effective management of traffic with the use of traffic signals. In essence, all these subsystems are correlated in that they provide vehicle monitoring and control, provide electronic payment services, provide driver and traveler information and help, managing emergency services, managing commercial vehicles, planning for system deployment and implementation, as well as managing transit. All these aspects are combined to work towards the achievement of effective and efficient traffic management.

Traffic Signal Control System 1

Figure 2: Relationship between Subsystems. Source: Henderson and Aravind (2015).

  1. Sub-System: Between Each of its Elements

In essence, travelers, who are the pedestrians and motorist rely on information provided by the travel agencies and controls that have been put on the roadside. In essence, different traffic signals dictate when the pedestrians or the motorists should proceed. These are based on the signals of the traffic light system placed on the roadside. In addition, different vehicles have to use different roads. For instance, a truck may not use the road designated for small vehicles.

  1. System Complexity

According to Hitchins (1992), there is a complex interrelationships between the system and the subsystems. The traffic light system is a complex one. Ideally, since the development of the system requires algorithmic input, as well as constant monitoring and surveillance, the traffic light system is predominantly complex, as it involves various stakeholders, including travelers, vehicles of different categorization, and the need for transportation networks. Also, since many incidents occur on the roads, the transportation agency has to take effective steps in automatically managing them. In addition, since the system can be intelligent and operate fully on its own, it can be considered a complex system.

  1. Dynamics of System

System dynamics utilize computer-aided approaches in making design and policy analysis. In essence, the traffic light system takes account of dynamic problems emanating from the complex environmental, social, managerial, and economic complexities. For instance, the management should ensure that all vehicles move smoothly; however, this is a loosely held assumption, and thus, the management should take account of aspects such as accidents that might cripple the movement of vehicles. In addition, the management has to reduce the travel time so as to take care of the ecological footprint. Also, the information centers should be able to provide reliable information.

Part 2:

  1. Problem/Challenge Identification

One of the major problems facing cities in the developing countries is the issue of traffic congestion. It is condition that occurs whenever road network use increases and is often characterized by longer trip times, slower speeds, as well as increased vehicular queuing. In practice, this scenario happens wing to the physique use of urban roads by vehicles. In essence, when traffic demand increases to a point where vehicles travel at reduced speeds and the traffic stream does not easily flow, there results some congestion. Also, it can be pointed out that as demand approaches the full capacity of the road, extreme traffic congestion is imminent. Also, being stuck in a traffic congestion is frustrating, and in some instances, it can lead to road rage.

  1. Problem Context

The problem usually happens in cities. Ideally, when the capacity of a road is met, then traffic congestion sets in. The scenario is especially common in developing countries which have not implemented comprehensive traffic control mechanisms. It generally occurs in instances when the volume of traffic generates a greater demand for space than the available road capacity, commonly referred to as the saturation point. Factors that aggravate congestion include traffic incidents such as accidents, weather events or road works. In this case, the travel time is significantly elongated and the carbon emissions increased due to increased fuel consumption.

  1. Stakeholders/Players

The main players for this problem include the government, which is mostly involved in construction projects for road networks. Also, the transportation agencies are also involved that are involved in putting in place the various traffic control mechanisms. Pedestrians and motorists are also key players. Ideally, these are the main road users, and thus, they are faced with the problem.

  1. Selection of System Methodology: Hard versus Soft Systems Methodologies

The Systems methodology encompasses the use of various techniques that are commonly divided into soft and hard systems. The soft systems methodology entails tackling systems that may not be quantified, especially systems that involve individuals interacting with one another or with systems (Checkland, 1989). According to Cundill et al. (2012), this method focusses on what should be done to categorically achieve improvements. It is based on human activity, improving the understanding, clarifying the problem, as understanding relationships and complexities. Checkland (1981) asserts that hard systems methodology on the other hand utilizes computer simulations, and mainly look for how to best achieve and test the most viable option for analysis or development. The hard methodologies are important for those problems that can be quantified, and thus, cannot take into account unquantifiable variables. They are applied in decision theory, simulations, forecasting, as well as mathematical programming. As such, comparing the two methodologies, the problem of congestion can be solved using the soft systems methodology.

  1. Application of System Methodology

  1. Brief description of the systems methodology

The systems approach is used for problem solving in systems orientation scenarios to make succinct definition of the problem, as well as the opportunities. Comprehending the problem and implementing a solution entails firstly recognizing the problem, evaluating alternative solutions, selecting the best system for solving the problem, designing it, implementing it, and finally, evaluating its success (Cavaleri and Obloj, 1993).

  1. Soft Systems Methodology

Stage 1: Problem Situation Considered Problematic

In this case, traffic congestion is the problem

Stage 2: Problem Situation Expressed

Traffic congestion increases travel time and increases the amount of greenhouse gasses released. It also leads to an influx of traffic, which cannot move as fast as it should usually being aggravated by weather conditions and traffic incidents. People waste resources in traffic jams, such as gas, money, and time.

Stage 3: Root Definitions of Relevant Systems

In this case, the traffic congestion can be solved by incorporating a variety of systems. For instance, implementing an advanced traffic light system is paramount. Within it, there has to be various subsystems, such as Surveillance subsystem, roadway subsystems, traffic management, and transit management subsystems that can lead to an increased traffic accountability and control

Stage 4: Developing the model

Putting in place advanced traffic control, corridor management, electronic toll collection, incident management and advanced vehicle systems will be handy in solving the problem. Ideally, when these aspects are inclined to those in stage three, it will lead to comprehensive traffic management as it will lead to increased road capacity.

Step 5: Compare Model And Real World (Gain Insights)

A traffic management system that can optimally operate and solve the issue of traffic congestion will include all these factors. For instance, incident management options will lead to possible diversion of vehicles so as to avoid congestion. Advanced vehicle systems may be expensive to implement while electronic toll collection is effective in dealing with tolling exercises.

Stage 6: Develop desirable and feasible interventions

Interventions are examples solutions in systems thinking (Flood and Jackson 1991). Interventions for this problem include the adoption of advanced traffic control system coupled with corridor management. However, advanced vehicle systems may be expensive to implement, but can be effectively be augmented by the incident and corridor management.

Step 7 Action to Improve the Situation

The best action is to implement an advanced traffic control system that is coupled with corridor and transit management system. Other subsystems that might be incorporated include surveillance, as well as traffic and transit management. These will combat the problem.

  1. Implementation Issues

The main implementation issue is lack of enough funding. These systems are expensive and thus inadequate funds may be a barrier to implementation. Also, inadequate experience, especially for personnel may be a stumbling block. However, the government may receive funding from the World Bank and also outsource experienced personnel.

  1. Conclusion

In conclusion, systems are important components in solving problems, including traffic congestion and incident management among other problems. The system approach is an important part of solving the problems by carefully analysing the problem and in turn formulating solution. However, for a system to operate, it requires the optimal functioning of the subsystems. As such, systems are vital components in the world we live in.


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