Sharif Digital Repository

Regardless of the traffic model and its application, an essential input of transportation models is the amount of demand which is usually described using Origin-Destination (O-D) matrix. Many reaserchers have developed different O-D matrix estimation methods using traffic counts, which allow simple data collection as opposed to the costly traditional direct estimation methods based on home and roadside interview. However, Link data is not sufficient to obtain an unique answer. This reaserch tries to estimate O-D matrix by using Automated Vehicle Identification(AVI) data. The research formulates the problem of the estimating O-D matrix as a bi-level problem. The upper level consists of... 

One of the most important required data in order to consult transportation studies is the amount of trip demand between different zones in the study region. Trip demand is usually presented in form of a table. Due to dependence of the demand on time, it gets classified in two categories: Static and Time dependent. In Time dependent problems, which the scope of this research is, trip demand is affected by network condition and the amount of traffic supply in short periods of time, e.g. 15 minutes. Using Traffic count and prior trip demand table in order to estimate the time dependent Trip demand is among the newest methods of travel demand estimation. In this research despite of older studies... 

Increasing of public transit market share in urban transportation is one of the major policies of urban system improvement. Lessening emission and fuel consumption are outstanding achievements of designing and operating effective public transit systems. As rapid transit systems play a major role in urban transit network, feeder bus lines can play as their complementary role in the urban transit scene. Feeder bus network provide a better accessibility and coverage for passengers. In spite of its important role, feeder bus network design is studied in a small number of publications in transit network design. In this study, a mathematical program model is presented to state feeder bus network... 

Encouraging passengers in order to use public transportation facilities is one of the goals of transportation planners. The most effective way to increase the market share of public transportation is enhancing its Level of Service via faster and more comfortable transportation in comparison with private vehicles. Exploitation of rapid transportation lines (Subway, BRT, and etc.) is justifiable in corridors in which the demand exceeds a minimum value. While in most of metropolitans such demand may not be present inadvertently in any of corridors, generating the needed demand and increasing the accessibility to public transportation is possible using feeder lines like feeder buses. In fact,... 

Reliable forecasting is a fundamental element of successful project management. Construction managers regularly control and monitor their project in order to ensure that their project performance is under control and within the acceptable control limits. Conventionally, the earned value method (EVM) is used to monitor project cost performance. However, its application to schedule performance using schedule performance index (SPI) has been widely questioned both by practitioners and researchers particularly due to poor accuracy early in the project. This study presents a novel activity-based framework, namely Weibull Evaluation and Forecasting Method (WEFM), for stochastic evaluation and... 

Optimum highway alignment problem is among the most substantial but large and complicated topics in transportation area. Infinite number of feasible solutions, numerous local optima and the constrained feature of the problem, associated with complex and mainly non-linear constrains, has put an extra effort into the problem-solving process. Moreover, the problem has a sensitive objective function to input variables. Due to the nature of the problem, conventional methods fail to find any exact solution, and so, using heuristic methods during the solving procedure is inevitable. Large-scale, complexity and sensitivity of the problem leads to a solution which is time-consuming and... 

Decreasing travel time is one of the main goals of passengers in urban areas for which transportation operators use various policies. Among these policies, expanding public transportation facilities is one of the urban planner major purposes. Considering the fact that making these facilities needs great investment, optimize use of the current facilities is valuable. Waiting time in transit station has influence on increasing passengers’ travel time and inconsistency, so coordination between different transit lines is necessary. In this thesis, creating coordination among different transit lines in a transit network by the use of integer programming is studied in the form of two models. In... 

In this research a model is proposed which determines flight frequency and aircraft routing for an airline network. It is supposed that origin-destination demand, costs, number of aircrafts in the fleet and their capacity, aircraft maximum daily utilization hours and origin-destination fares are given. The model attempts to maximize airline profit and determines flight frequencies, number of passengers carried between two cities and number of passengers who travel with an indirect flight, considering fleet constraints and an operational aircraft routing.The model is tested with a hypothetical numerical example. The results indicate that the model uses maximum aircraft capacity and daily... 

A basic highway design problem is to find the most economical alignment connecting two given end points based on topography, soil conditions, socioeconomic factors and environmental impacts, while satisfying a set of design and operational constraints. The cost function complexity and numerous limitations such as highway design criteria have made this problem a NP-hard one. In this study, a swarm based searching algorithm has been applied to a three dimensional highway alignment optimization model. The spatial data has been exploited from a GIS databases using a heuristic swift approach. In addition, the majority of cost items that depend on highway design have been extended in a practical... 

Railways managers have strong economic incentive to minimize the track maintenance costs, while maintaining safety standards and providing adequate service levels to train operators. . The aim of this study is providing a method for repair and maintenance management of Iranian Railways and improving previous investigations.This study consists of three parts. First, providing a new definition for the rail's status based on fuzzy theory. Second, a cumulative damage model based on a Fuzzy Markov process is applied to model the deterioration of the track. For this reason, tracks are categorized into six classes, so that those tracks with similar traffic loads and geographical location are... 

Due to large range searches (there are various alignments between two points) as well as the complex and non-linear cost functions and a variety of geometric constraints, the problem of optimal railway alignment is known as a difficult problem. For this reason, choosing an alignment between two points is usually done based on a limited number of alignments put forward by experts. In recent years, the study of the railway alignment optimization raised again due to the importance of optimization and introduction of various algorithms and their progress in solving various problems. It is expected that applying metaheuristic optimization algorithms, such as methods based on Swarm intelligence... 

Knowing the trip information such as paths that travelers prefer to choose is useful for practice in developing certain transportation planning step. There are different methods such as using GPS and conducting survey for volunteer travelers in order to understand actual paths. Obviously, all of these methods have some deficiencies. This research suggests and examines a method for estimating travelers’ path by using cell phone data. The main advantage of using these kinds of data is enabling the process of collecting information without any active interference of the users. A big data set consisting of 300,000 cell phone users’ information in the city of Shiraz is studied to achieve this...