فصلنامه راهور
پیاپی 42 (تابستان 1397)

The researchers introduced various geometric designs for the fields. So far in Iran, despite the high exploitation of the field, precise studies have not been conducted on the subject of the study and comparison of its behavior. In this study, the values of time-delay traffic indicators, velocity and capacity of Aimsun traffic simulation were studied and compared. In the simulation done, there are seven cycling modes and some geometric characteristics such as the number of lines entering the field, Number of lines around the field, the angle of the branch (along the street), and the diameter of the central island of variable, and some other; line width, input radius to the field, the input speed to the field and the speed round the field are considered constant. Based on the results of this study, by increasing the number of street line (when the angle of the branch is 50 degrees, the number of line of the field is 3-line and the number of street line increases from 1 line to 2 lines), the delay increases by about 50 percent and the speed decreases by about 30 percent or by increasing the number of field line (when the angle of the branch is 70 degrees, the island diameter is 100 meters, the number of the street line of the 2- line and the number of field line increases from 2 lines to 3 lines), the delay will decrease by 12 percent and the speed will increase by about 10 percent. As the diameters increase (when the angle of the branch is 90 degrees, the number of the street line is 2-line and the number of the field line is 3-line), circulating situations that is more turning to right, the delay will decrease by 28 percent and the speed will increase by 16 percent and situations that is more turning to left, the delay will decrease by 36 percent and the speed will increase by 23 percent

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The increase in population growth and the expansion of the streets and, consequently, the rise of cars have increased the crowds, congestion, air pollution and also noise and become one of the major problems of metropolitan cities. Some of the main objectives of transportation management policies are included reducing vehicle numbers, reducing the travel time of public systems and improving access to the public system as absorption policy and fuel pricing, parking pricing and entering the city center as disposal policy. The pricing policy in the city’s central area (CBD) was one of these policies, and knowing its impact on controlling the entry of cars into the area is an important issue. So,The purpose of this research is to evaluate the reduction of the use of personal vehicles due to the pricing of the in the city’s central area (CBD) before and after the improvement of the public transportation system.

In this study, since there is no possibility to observe the conditions for improving the public transportation system, so has been used the preference method and the information has been collected through in-person interview with personal vehicle users. With notice that the purpose of the trip was job for more than 50 percent and about 25 percent for purchase, the impact of cordon pricing and improving the public transportation system was examined for all travels, business trips and shopping trips. Interviewees responded to questions about travel characteristics, socio-economic characteristics, and their choice options in terms of pricing policies for personal vehicles.

The results show that with the existing public transportation and pricing of 40000 and 80000 rials , respectively , in 68 and 89 percent of trips, passengers have changed their personal vehicle and in terms of improving public transportation seystem are 93 and 98 percent respectively.

 in improving and expanding public transportation systems take care, and then, pricing is to be used with the goal of reducing the loging cars and making money for further development of public transport.

Roads, humans, vehicles and the environment have a significant role in accidents. Undoubtedly, road and its geometric and technical condition as an important part of traffic control plays an important role in the occurrence of accidents. Studies show that the correction or removal of accidental points has a significant impact on safety improvement and reduction of traffic accidents and reduction of damage. The present research is aimed to identify the incidental points in the roads of Moeslati in Qom province. The axis studied in this research is the freeway Qom-Tehran, which is one of the important axes of these two provinces and countries. This axis is 130 kilometers long and connects two centers of Qom province and Tehran province. In this research, VASPAS method, which is a multi-criteria decision-making technique, is used to identify the accidental points from among the 11 points of Qom-Tehran axis. Accidental points are prioritized according to three criteria: damage accident, injury accident and futile accident. All calculations have been done using MATLAB software that the relationship between the method of the VASPASS is written in its environment, and it is able to detect incident points with respect to input data. The obtained results show that the range of 0 to 5 km is the most accidental area in the Qom-Tehran axis, and areas 50 km up and 16-20 km are the second and third accidental areas, respectively, and the rest areas also are ranked. Finally, the index method was used for the validation of the proposed solution method of this research, and at the end Spearman correlation test was used to examine the similarity of the results. The test output shows high correlation of results (0.9). According to the analysis done, the points and areas wheretheir crash statistics are higher, it has more priority to carry out safety reforms and projects.

This research in the field of traffic accidents and traffic issues in terms of general health of the community is considered as a basic issue. Because the economic, psychological and health costs causesd by accidents sometimes more than the amount of financial resources needed to implement development plans, it can be effective in changing driving behavior and driving accidents rates. In the present study, While presenting a review of the hazardous driving effects caused by various factors in driving accidents, have been investigated the factors affecting drivers' hazardous behaviors. The research sample is 417 drivers from Rasht city. a modified version of the Manchester questionnaire has been used to assess the hazardous driving behavior. The NEO questionnaire was also used to measure personality dimensions. Other effective factors were collected using various studies. The analysis of hypotheses was done using the software of structural equations and path analysis method. According to the research findings, a significant relationship approved in social desirability, social norms, Legitimacy, lack of satisfaction of life, social need, neuroticism, extroversion, flexibility, agreement and conscientiousness. But the probability of detecting violation and hazardous driving was rejected

Because of the infrastructure and critical role of roads, the displacements made in them have an enormous impact on the economic growth of countries. In recent years, road accidents have increased dramatically due to the lack of standardization of vehicles and existing roads, environmental factors as well as roadside contributors. Failure to observe safety principles in geometric design and maintenance plan of roads has caused serious damages to the country. On the other hand, modeling of crashes and examining the variables affecting its occurrence has not been done to provide corrective options. Therefore, in this paper, with the help of the intelligent artificial neural network model, the simultaneous effect of atmospheric factors and road pavement collapse was investigated and modeled on the occurrence of accidents on the busy routes of Khuzestan province. Meteorological data and accidents statistics for the statistical period of 2011-2014 were prepared. Independent and dependent variables, as inputs and outputs of the neural network, were defined at three levels of total accidents, damage accidents and injuries accidents. The modeling was conducted using the Neuro Solution software as leading and based on the Levenburg-Marquardt training principle and Sigmoid axon transfer function. The results of various architectures showed that the designed neural network, with high explanatory factor, can model the total number of accidents. In this model, the most effective parameters on the creation of accidents were weather conditions (rain and cloudy weather), road failures (PCI index and prevailing failures), and another factor (the number of forward-facing crashes) as model inputs. For modeling of damage accidents, effective inputs included the number of accidents (damages and losses), road failures statistics (PCI paths and prevailing failures) and weather conditions at the moment of accident. The achievement of the high-level explanatory factor in this model also reflects the ability of the architectural neural network to model the crashes. The obtained results show that using the variables introduced, prediction of accidents can be used in terms of the rate and severity of accidents (incidence, fate or damage). Also, the impact of atmospheric factors on the occurrence of accidents is an undeniable fact, and it is necessary to modify the routes, increase road safety and inform the drivers, to reduce accidents during the occurrence of precipitation or frost and mist conditions

Today, speed management to achieve safety is a major problem for most countries in the world. One of the most effective methods of speed management in the world is the use of traffic relaxation tools. Traffic relaxation is a set of strategies for reducing the speed and volume of traffic, and they are carried out in two ways of engineering (physical) and non- engineering (perceptual)), which, of course, have different levels of influence. The purpose of current research is to prioritize the various strategies, strategies and measures of traffic relaxation based on the impact level. With this approach, existing options have been prioritized using the hierarchical analysis process method. This is done by designing and distributing a questionnaire among more than 50 experts using paired analysis using EXPERT CHOICE software. The results show that strain speedand longitudinal lines with a score of 12.26% and 10.3% are the most effective measures and physical blockers, diameter and islands rising along the intersection with 2.64%, 2.47% And 64.1% are considered the least effective traffic relaxation measures