Sharif Digital Repository

Modelling passengers’ itinerary choice behaviour is valuable to understand the increasingly competitive airline market and predicting air travel demand. Research in the choice behaviour of air travellers has evolved to include an analytical focus on variation in the sensitivities of travellers to factors influencing itinerary choice. That is, some choice studies have moved beyond a focus on assumed representative, mean-level sensitivities toward a goal of representing the distribution of preferences across a sample. An important issue that remains is whether the insight gained in previous studies, which focussed on preferences in mature markets with relatively high per-capita rates of air... 

Natural disasters claim major losses in human lives and belongings, as well as national infrastructures. Taking major earthquake as an example, the study has considered two sides of the problem, both before and after the incident. The former side is formulated as a multipartite optimization problem, in which each party’s activities are directed toward the long-term solution of the original problem. A heuristic method to solve the multipartite problem, and solve three example problems to show the applicability of the method was proposed. The solutions of example problems show that a directed problem solution reaches a better solution (in terms of the objective function value) than the... 

Drivers, who are approaching the intersection at the beginning of change interval, are faced with two choices, either to continue moving, or to brake and stop.The zone before the intersection, where drivers’ decisions are not predictable, is called dilemma zone. Several factors influence this decision. According to stochastic nature of this decision, it seems that Logit models are useful tool for studying such issues due to their special structure. In this thesis, to study the drivers' behavior during the change interval and factors that affect the behavior, the decision process of the drivers at the beginning of the change interval is modeled In this modeling, we used the collected data of... 

Raising number of vehicles and increasing tendency of people to possess their own cars have posed a lot of expenses on users. One of the most significant of them is the time it takes to travel between origin and destination. Several researches have been conducted so far in order to evenly distribute travel times among transportation network users. A variable that has been neglected in many of these studies is travel time variability. Users, obviously, need to know not only the travel time, but also the probability of varying this time. In this research, an analytical model has been developed on a geometrical basis that includes both traffic conditions and intersection characteristics to... 

Traffic accidents are becoming one of the most important challenges threatening global public health. Yearly about 25000 persons die beacause of traffic accident in Iran. While trucks account for around 8.3% of the total number of vehicles in Iran’s roads, they were involved in 20.5% of all fatal crashes in the year 2014. This shows the importance of addressing the problem the truck drivers’ safety. This study aims to obtain an understanding of the relationship between the effective variables on safe heavy vehicles driving and develop a new structural equation model by this variables. For this purpose, data were collected using Driver Behavior Questionnaire, Attention-Related Driving... 

Drivers' behavior is an influential factor in more than 90% of driving accidents. Due to the increased traffic load due to the use of private cars, as well as traffic congestion restrictions for the use of private cars at large city centers, the use of public transportation means for transportation of goods and passengers in order to reduce traffic load is a very convenient option and it is sometimes necessary. Therefore, it is very important to examine the behavior and character of drivers of public urban vehicles in order to increase traffic safety. The purpose of this research is to present and develop a descriptive model that describes the behaviors leading to at-fault accidents for... 

Studies show that Pedestrians are at fault in 59% of the vehicle-pedestrian accidents. The traffic crash statistics show the importance of understanding factors of pedestrian errors. If pedestrians terminate their waiting behavior during the red light period and cross the street, they would put themselves in danger. Pedestrians’ red-light violation is a type of highly dangerous behavior occurring at intersections. A total of 1130 pedestrians approaching the intersections during red light periods were observed from the videotapes data collected at 6 intersections in Tehran, Iran. Pedestrian crossing behaviors are classified into immediate crossing behavior and waiting behavior. A logit model... 

In recent years with the progress of technology in different areas, the production of self-driving cars has been feasible. We can expect that vehicles of transportation networks will consist of both self-driving and regular cars in the future. In this research, a new method will be proposed for urban transportation networks to change the direction of reversible lanes according to the network's state. These reversible lanes are exclusive for self-driving cars. Human drivers are not allowed to enter these reversible lanes, considering the limitations of human ability compared to a computer in analyzing data and making decisions about moving direction. To achieve this goal, reinforcement... 

Natural hazards such as earthquake take many lives each year and cause significant damages to infrastructures such as transportation networks. Whether after occurrence of a natural disaster like storm in order to evacuate, or after an abrupt event such as earthquake in order to provide emergency measures, a transportation network should maintain its functionality and performance in an acceptable degree and should recover in an effectively short period of time. In this study, the link or the set of links which their removal causes significant damage to the transportation network are identified. A specific index (N-Q index) has been used to describe the performance of the network. In addition,... 

The results of the conducted research indicate that although there is a period of time for pedestrians to cross the street safely at signalized intersections, some pedestrians cross the street when they find a space between the passing cars even though their traffic light is red. This behavior has caused a great increase in the number of pedestrian accidents. Understanding pedestrians’ behavior can be helpful in reducing these types of accidents.In order to analysis the pedestrians behavior while crossing the street two types of data were collected; a field questionnaires and a concurrent video image recordings of the pedestrians crossing the streets.The 435 questionnaires collected... 

Serious concerns in the field of road safety, with over 1.35 million fatalities and 50 million injuries annually worldwide 90% of which occur in developing countries such as Iran highlight the importance of research in this area. Also, limitations in accident data have driven studies focusing on preventive methods such as traffic conflict analysis. Furthermore, the application of conflict indicators with various natures and their utilization in estimating the severity and frequency of accidents, particularly at unsignalized intersections due to the nature of maneuvers, present promising opportunities for deeper investigation. The aim of this study is to evaluate factors influencing the... 

Left-turn operation is a critical component in the safe and efficient operation of a signalized intersection. The proper type of left-turn phasing results in reduction of traffic delay and number of accidents. A review of the literature indicates that different warrants have been proposed for the installation of the protected left-turn phase; however, there is not a consensus to implement a specific warrant up to the present. In general, the warrants fall into four categories: traffic volume, operational characteristics of traffic, intersection geometrics and accident experiences. Considering the high rate of accidents resulting from left-turn movements at signalized intersections in Iran,... 

High number of traffic accidents in Iran and its rate which is well above the world's average is a major issue of concern. The results of recent researches show a direct relation between survival rate of traffic accidents' injuries and the Emergency Response Time (ERT). The main objective of this research is to analyze different aspects of ERT in Tehran, Iran and to compare these results with the International standards. This study intends to compare the selected routes by ambulance drivers with the shortest paths recommended by EMME/2. Results of analysis show that when the travel time between accident scene and the emergency dispatch center is less than 8 minutes, the possibility of... 

Identification of hazardous locations and improvement of these locations are the basis of most highway safety inspection programs. In most cases, performance of successful highway safety management programs requires accurate accident data, and availability of these data. Unfortunately, in Iran, there is some uncertainty about the accuracy and completeness of these data to be used in a safety management program.The main purpose of this study is to identify and compare highway accident hazard index for a two-lane rural highway in Iran using two different methods. In the first method, traffic and alignment characteristics of the highway were recorded through roadway auditing technique, GPS... 

For any country, the road system is an important part of its infrastructure which can affect economic development. A good level of service for a road system requires implementation of work zone projects to maintain it which usually close one or more of the lanes available for traffic. Lane reductions could cause a disturbance to normal traffic flow and speed reductions, further resulting in a reduction of road capacity and an increase of traffic delay. In addition, work zone capacity and traffic delay are the two critical indices to determine whether the effectiveness of traffic control systems is acceptable or not. Hence, the accurate estimation of capacity and traffic delay in work zones is of... 

Estimation of travel time in transportation engineering has always been an important issue. So far, most of travel time studies have focused on freeways and highways, and very few research have been done on travel time estimation for arterials. In this study, by using shock wave concept, a probabilistic model is developed for estimating the travel time of a signalized arterials consisting of two pre-timed signalized intersections. This model can be used in both coordinated and non-coordinated signals. In this study, travel time and traffic volume data were collected for Fatemi Ave. in Tehran, Iran. By using these data, some parameters of VISSIM simulation package were calibrated to reflect... 

Nowadays, there are three factors in traffic issues, which are very important. These factors are delay time, fuel consumption and environmental pollution. A good choice of the type of traffic nodes (intersection and roundabout) can play an important role in reducing some of the traffic problems such as: the amount of vehicles' delay time, energy consumption and pollution due to the transport system. In this study, we try to identify factors that influence delay time, fuel consumption and air pollution in different types of intersections and roundabout. According to previous studies, these factors were such as: variables of each route volume, distribution of through, right turn and left turn... 

Traffic accidents, is an inevitable event. There are various reasons for accidents and almost not possible to identify all of them, but a careful study of these phenomena can identify the main causes of this phenomenon. This study estimates Multi-Vehicle severity in terms of different weather. Accidents data the Including 2,949 accidents recorded during 1388 to 1392 in six axes of the East Azerbaijan roads in three levels of accident severity: damage, injury and death. For modeling, sequential Logit model was selected because accidents severity have Sequential nature. This model used the Stata software, version 12, for evaluation and sensitivity analysis. The obtained model consists of... 

Natural disasters, earthquakes in particular, claim many human lives and damage major lifelines such as transportation networks. Transportation networks play an important role in various stages of response to disasters, such as evacuation, search, rescue and reconstruction missions. Hence, special attention must be paid to transportation networks in any disaster management system. Hence, in order to reduce the impacts of earthquakes on denser cities and metropolitan areas, analysis of the resiliency and vulnerability of critical infrastructures such as transportation network, can be used as an effective strategy.The resiliency and vulnerability of transportation network have attract a lot... 

The road authorities of a city have the responsibility of constantly assessing how well their city performs when traffic conditions are taken into account. In many metropolises around the world, if not taken preventive measures, there will be observed a density above the network capacity and a noticeable decrease in the level of service, especially in the morning and evening peak hours. Also, the dynamic congestion pricing of certain areas based on the traffic condition has always been considered significant by urban planning officials. Since this is not possible except by constantly assessing the current traffic state, a variety of methods have been used to predict the future traffic...