TRAFFIC MANAGEMENT STUDIES
Year:2010 | Volume:5 | Issue:16|Papers Count:9

Human beings, like other creatures, have biological and circadian rhythm. Survey studies have shown that shift work and high variability of working hours disrupt our circadian rhythms, resulting in inadequate sleep quality. The aim of this descriptive and analytical study was to investigate the bus drivers' sleep quality. This study was carried out on 110 bus drivers in Tehran (South, East and West terminals, 60, 30 and 20 drivers, respectively). To determine sleep quality, the Pittsburg Sleep Quality (PSQI) model was employed. The mean age for the drivers was 41.9±9.7 years, of whom 92.7% and 7.3% were married and single, respectively. Meanwhile, the mean working time and BMI index for the drivers were 15.6± 8.7 years and 25.9±3.9 kg/m2, respectively. Overall, 21.8% of drivers have good sleep quality, while 78.2 % have sleep disorders. Statistical analysis of the data revealed that variables like job satisfaction, the night staying at home, and sleep disorders were significant (P< 0.05). This observation suggests that night shift work might have provoked changes in sleep quality of the bus drivers. Directed researches and education may pave the ground for traffic incidents decreases.

Corsim is microscopic simulation software in traffic engineering with high capability in analyzing urban networks. Nowadays, the use of simulation software is a fundamental way to solve traffic problems. Applying simulation software is very economic, yet the results are obtained in very short time without any traffic disturbances, whereas using field tests, in addition to being expensive, disturbs traffic flow. In this research, capacity analysis and flow optimization of Dastghaib Street, between Ostad Moin Boulevard and Ayatollah Saidi highway, is analyzed by Corsim in Tehran. Input data was taken by municipal GIS files and field investigations. Simulation of the network was proposed in morning and afternoon peak hours. The results showed that when Dastghaib Street was made one-way, total network delays were decreased 7.3 percent and 4.9 percent in the morning and afternoon peak hours, respectively. Also, total travel time decreased from 124 hours to 120 hour, while average speed increased from 20 km/h to 22 km/h in morning peak hours.

Road casualties have declined in most countries in the European Union during the last twenty years. Designing new cars and technical methods in safety, enforcing traffic laws, as well as immediate emergency services have helped preventing accidents. In recent years, various measures have been conducted in the European Union to increase pedestrian safety. For this purpose, the European Committee was formed to address vehicle safety, and various studies on pedestrian safety were conducted. The Committee’s task was to determine the accepted test methods and standards that the cars need to met. Based on this research, suggestions regarding vehicle structure were offered and test methods for pedestrian protection in frontal collisions were determined. Reviewing accidents statistics in different countries show that most fatal pedestrian accidents are related to head injuries as result of collision. One of the new methods to reduce injuries is to change the structure’s material and body panels and replacing them with integrated steel laminated composite panels, especially the car’s hood. This significantly reduces acceleration, which, in turn, reduces fatal accidents. Employing multi-layer panels in automotive body structure also has other advantages, such as increasing crash energy absorption, reducing occupant damage, reducing car weight and fuel consumption.

Accidents are multi-causal phenomena and could not be controlled without taking all the causes into account. Among the most important factors affecting the classification of the pedestrian-hazardous (accident-causing) walkways are accidents’ environmental factors– which have not yet been considered comprehensively using existing methods. Statistics and data about the current situation are complex and non-linear. Thus, the classification of these passageways cannot be done correctly using simple mathematical models and linear combinations. In this research, an observational classification method using artificial neural networks is presented, and a new model for pedestrian-oriented classification of hazardous urban walkways has been proposed. In this model, artificial neural networks and statistics data on pedestrian accidents and walkway risk level are used, while control, traffic, and geometric parameters are considered simultaneously. The factors involved in this model include length and width of the roadways, width of the walkways, parking on the sides of the roadways, median’s width, roadway’s speed limit, roadway’s lights, quality of upper asphalt layer, segregation of roadways and walkways, presence of police, proportionality of velocity and land use, and proportionality of pedestrian pathways and gradient of roadway. Being observational, this model could significantly increase the accuracy and efficiency of the process of classifying pedestrian-hazardous urban passageways.

Variable message signs (VMSs) are among traffic control devices used to inform drivers along the road. These signs are fixed differently; they may be posted above the road, fixed on the shoulder of the road, etc. The information shown on VMSs is operated from traffic control center. These signs are used to effect drivers in order to improve their performance. Information shown on VMSs include travel time, the average speed between the given source and destination, traffic congestion, work zones and road construction along the road, information on special events, such as incidents or accidents happened to help the drivers make a proper decision, weather conditions, and so on.In this paper, an overview of the technical and operational specifications of VMSs used in Iran is presented first. Then, some real instances of fixed VMSs in inter-city roads are introduced. Finally, the operation and application of these VMSs are discussed in accordance with ITS application.

The complexity of transport issues in cities has nowadays perplexed experts and planners. A variety of policies and decisions adopted by municipal executives to solve the problem has just provided temporary solutions, the efficacy of which has been excoriated by critics, as well as many citizens. Managers and planners have come to the conclusion that most investments, especially those allocated to the transportation management subsystems, although resulting in improvements in the short-run, cannot culminate in a sustainable situation. 6Scrutinizing the two main challenges existing in comprehensive management plans for urban transportation, the paper introduces a prospective approach as a new strategy in order to solve transportation problems. Similarly, while explaining some of the significant procedures for prospectivism, the papers introduce its maxims, essentials, and basic terms and concepts. Finally, a proper approach is proposed for applying futurology in transportation.

The first part of the present paper presents a simple algorithm of the ABS operation in a quarter vehicle model. In the second part, the optimum and effective domain of friction of coefficient is obtained by the simulated program. It is concluded that decreasing friction of coefficient domain or increasing the friction of coefficient magnitude will reduce the stopping distance and stopping time. The modeling of brake has been done in the simulink of Matlab software. The desigend model is completely parametric and can investigate the effect of different variables in different conditions.