TRAFFIC MANAGEMENT STUDIES
Year:2009 | Volume:4 | Issue:12|Papers Count:8

This paper aims at designing an optimal network model for urban transportation in Ardabil. In this model, the three important criteria are time, cost and quality. The proposed model minimizes the total traveling time and cost, and, at the same time, maximizes the quality of the transportation services. Because of conflictions among the objectives, and in order to consider the decision makers' preferred structures more effectively, a Lexicographic Goal Programming (LGP) model was developed. Then, an actual case from Ardabil city bus network was illustrated. The solutions confirm high level differences and improvements in the performance of the urban bus network, compared to current bus network situation.

Roads, humans and vehicles are the three major factors in road traffic accidents occurrence. Road geometry, as one of the fundamentals of the road environment, has a key role in reducing human errors. The treatment or elimination of black spots has a great influence in safety promotion, reducing the number of road traffic accidents, and, subsequently, diminishing damages. In this paper, the process of analysis and assessment includes: 1) accident location identification, 2) costs of damages, and 3) remedial works.Based on statistical analyses and assessments, engineering economics techniques and hierarchical methods were carried out. As a case study, Shiraz–Isfahan corridor, which is an important arterial road in Iran's road network, was chosen. The results are as follows:1- Calculation of the accident costs shows the fact that the average costs of a fatal accident is approximately 5 times the costs of an injury accident and 9 times the average of damage accidents. 2- The statistics and data confirm that %20 of accidents occur in the accident-prone places (black spots). This represents the importance of treatment and investment for safeguarding critical and accident-prone points in the roads.3- The average of Benefit/Cost ratio (B/C) in executing safety improvement projects in Shiraz–Isfahan corridor is 20.3, which shows the strong economic feasibility of such projects.4- The ranking for implementation of safety projects in a multi-criteria decision making model is based on the number of accidents. 5- According to the accomplished analyses, the points and locations with more traffic volume have more priority for the implementation of safety projects. 

The present study emphasizes increasing motorcyclists’ safety, making them lawabiding and introducing a suitable approach to decrease accidents. The method of research is descriptive-measurement. To examine research hypotheses, a questionnaire, including open-answer and close–answer questions, was provided and distributed among 387 motorcyclists in Garmsar. The repliers were randomly chosen from three parts of the city through classified sampling and answered the questions. Then, the data were collected and analyzed. Also, the role of the motorcyclists on inter-city accidents in Garmsar, was examined. Next, the data collected were analyzed using SPSS software. The results showed that motorcyclists’ control plans have been effective on decreasing inter-city accidents in Garmsar.Also, the motorists’ driving skills played an effective role on decreasing motorcyclists’ accidents.

The widespread use of intelligent transportation systems necessitates guidelines for choosing the best position for installing the intelligent transportation subsystems. Among the existing intelligent subsystems, surveillance systems are the most important.In this paper, a guideline for choosing the best position for installing the surveillance systems in harmony with other intelligent subsystems on a specified road is introduced. A survey between managers and technicians of Ministry of Roads and Transportation of Iran is conducted to determine the main goals of using surveillance systems and suitable measures of performance as well as their importance weights. A worksheet is, then, prepared which shows the important characteristics of surveillance systems and their weights.Level of surveillance for a specific road can be determined using the characteristics of that road. Three level of surveillance are defined. Also, there is a list of important points for each level of surveillance. The important points on the considered road being chosen, their exact position and characteristics of the camera must be determined. The proposed guideline is used for a rural road in Iran and its advantages have been shown.

Along with the development of human societies’ needs and, as a result, the development of the respective services performed by industrial, official and welfare centers, transportation serves as a link between support and demand of these services. On the other hand, transportation is effecting and affected by such a development. Nowadays, the multifaceted approach to the issue of development in order to attain urban sustainable structure, has led to the theory of sustainable transportation to be viewed as a strategy by urban experts and managers. One of the most important issues in sustainable transportation theory is energy. The high ratio of transportation energy consumption per capita and its direct effects on environment as well as its consequences on society development indicates the position of renewable energies in sustainable development theory. Because of the debilitation of energies acquired through fossil resources, many national, regional and international associations are now looking for the support programs for developing the technologies of various kinds of renewable energies. In this paper, after providing a comprehensive definition of renewable energies and sustainable development, a number of measures to evaluate the position of renewable energies in passenger sustainable transportation theory are introduced. These measures and the definitions presented here may clarify this new theory in urban management.

Road safety is usually identified by “no crash” and “no casualty” criteria and its importance is usually measured conversely. It is a complicated matter consisting of different components. A deep comprehension of road safety and recognizing its effective elements as well as assessing the impact of these elements on the safety of roads is absolutely necessary. This needs be performed to achieve optimal allocation of restricted road safety budget. Since measuring the safety of roads just on the basis of the crash or casualty rate has no advantages in recognizing and resolving the problem, researchers have proposed using performance indicators in road safety extent.To evaluate the safety of roads, a number of methods have been proposed. These could be divided into two major groups: socioeconomic road safety performance evaluation programs, consisting of MCA and Cost- Benefit Analysis (budget evaluation methods) and structural ones, consisting of statistical methods and data mining. Of these, methods simultaneously assessing the uttermost number of road safety indices, such as composite road safety performance evaluation, data mining, and DEA, are more appropriate, while other methods, such as Cost- Benefit analysis, could play a supplementary role. In this paper, by reviewing road safety evaluation methods, and using the Principle Component Analysis (PCA) as a way of reducing variables to evaluate massive crash data more correctly, the most appropriate methods have been proposed.

When the demand attains to supply in transportation systems, policy makers are face with a spectrum of solutions with respect to supply and demand management. In such cases, the easiest thing to do may be supply increase, which may be performed by fleet addition. When there are restrictions, such as minimum headway limitation and budget affordability, upgrading the technology, adding supplementary services or applying demand management strategies are the choices. In the absence of sufficient budget, or for a short-term solution alongside technology upgrade, supplementary services may be considered. In such cases, additional optimal capacity should be determined regarding the initial investment costs and rehabilitation costs of both systems.This paper is presented to deal with and improve the public transportation systems, which have a fundamental role in urban transportation. Furthermore, the equilibrium of demand and supply, once supplementary systems and the practical constraints, such as time, costs and technical limitations have been identified, is of great importance.After presenting an overview regarding indices structure and demand and supply index development, Tehran trolley bus is investigated as a case of saturated system.Although the subway system, as the preferred technology, in the mentioned corridor is under construction, the short-term solution is diesel bus addition alongside the trolley bus, because of some limitations in power capacity of the trolley bus lines and available fleet. The present paper presents a method to determine the supplementary fleet regarding the predefined demand and supply indices.