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Multi-objective cordon price design to control long run adverse traffic effects in large urban areas
, Article NETNOMICS: Economic Research and Electronic Networking ; Volume 16, Issue 1-2 , August , 2015 , pp 1–52 ; 13859587 (ISSN) ; Rezaeestakhruie, H ; Poorzahedy, H ; Sharif University of Technology
Springer New York LLC
2015
Abstract
Pricing is seen as a viable alternative to manage the demand for transportation facilities. While supply increase might aggravate the problem, pricing is envisaged to relieve large cities from adverse traffic effects (congestion and pollution, among others). Nevertheless, pricing has its own drawbacks, often overlooked by the operators of the networks. It will cause changes in the travel behavior of the different groups and their demands (shoppers, retailers, and even basic businesses/ employees). This paper presents an extensive review of the subject, and an equilibrium model to estimate the long–run effects of a cordon pricing scheme. The problem of designing a price for a Central Business...
Reliability-based network flow estimation with day-to-day variation: A model validation on real large-scale urban networks
, Article Journal of Intelligent Transportation Systems: Technology, Planning, and Operations ; 2017 , Pages 1-23 ; 15472450 (ISSN) ; Sadat Mirjafari, P ; Poorzahedy, H ; Sharif University of Technology
2017
Abstract
Day-to-day variation in the travel times of congested urban transportation networks is a frustrating phenomenon to the users of these networks. These users look pessimistically at the path travel times, and learn to spend additional time to safeguard against serious penalties that await late arrivals at the destinations. These additional expenses are charges similar to the tolls in system equilibrium flow problem, but may not be collected. With this conjecture, the user equilibrium (UE) formulation of congested network flow problem would lack some necessary factors in addressing appropriate path choices. This study, following a previous work proposing pessimistic UE (PUE) flow, aims to show...
Reliability-based network flow estimation with day-to-day variation: a model validation on real large-scale urban networks
, Article Journal of Intelligent Transportation Systems: Technology, Planning, and Operations ; Volume 22, Issue 2 , 2018 , Pages 121-143 ; 15472450 (ISSN) ; Mirjafari, P. S ; Poorzahedy, H ; Sharif University of Technology
Taylor and Francis Inc
2018
Abstract
Day-to-day variation in the travel times of congested urban transportation networks is a frustrating phenomenon to the users of these networks. These users look pessimistically at the path travel times, and learn to spend additional time to safeguard against serious penalties that await late arrivals at the destinations. These additional expenses are charges similar to the tolls in system equilibrium flow problem, but may not be collected. With this conjecture, the user equilibrium (UE) formulation of congested network flow problem would lack some necessary factors in addressing appropriate path choices. This study, following a previous work proposing pessimistic UE (PUE) flow, aims to show...
Telecommuting suitability modeling: An approach based on the concept of abstract job
, Article Transportation ; Volume 33, Issue 4 , 2006 , Pages 329-346 ; 00494488 (ISSN) ; Kermanshah, M ; Poorzahedy, H ; Sharif University of Technology
2006
Abstract
A new approach to modeling telecommuting suitability is proposed in this paper. The approach, based on the concept of abstract job, can be employed to assess the level of suitability for telecommuting of the bundle of tasks comprising a job. By abstract job is meant a way of considering jobs on the basis of their elements and tasks, representing the general structure of the job. In this study, the basic tasks a job is composed of, pertaining to telecommuting suitability, are identified. To show the applicability of the approach, discrete choice models are calibrated, based on a sample of 245 employees in Tehran, Iran, indicating that from among the 6 tasks identified, 5 tasks are...
Simulating sustainable transport using a predator-prey model
, Article International Journal of Modelling and Simulation ; Volume 25, Issue 3 , 2005 , Pages 147-155 ; 02286203 (ISSN) ; Vaziri, M ; Poorzahedy, H ; Sharif University of Technology
Int. Assoc. of Science and Technology for Development
2005
Abstract
A new generation of sustainable development research uses mathematical models. This article proposes a heuristic approach to analyze sustainability in a society utilizing a mathematical model. First, an alternative definition of sustainable development has been proposed. Second, the interactions between transport and the other major components of a society have been simulated by a system of differential equations in the form of Lotka-Volterra type predator-prey model. Some of the model parameters have been considered as control parameters in order to reflect the impact of strategies of reducing transport and economic levels of activities in favour of the environment on the one hand, and...
World city mode choice: Choice of rail public transportation
, Article Scientia Iranica ; Volume 11, Issue 4 , 2004 , Pages 320-331 ; 10263098 (ISSN) ; Tabatabaee, N ; Kermanshah, M ; Aashtiani, H. Z ; Toobaei, S ; Sharif University of Technology
Sharif University of Technology
2004
Abstract
The choice of technology to transport passengers in large metropolitan areas is an important issue everywhere. There are many factors involved in this choice. This paper deals with the possibility of the objective use of available information in the analysis of the suitability of a rail public transport system for a city. A database has been made from publications on public city transportation and country level information. Logit models of choice have been calibrated by the maximum likelihood and nonlinear least square methods based on the acquired information. Each city is treated as an "individual", choosing rail or non-rail modes for its trips. Only cities with a population of more than...
Solving the Bus Rapid Transit Network Design Problem with Ant System Algorithm (in Realistic Urban Network)
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossein (Supervisor)
Abstract
Network design problem (NDP) is an important problem in transportation planning, in which transit network design is one the most important problems. Public transportation means, however, can not meet urban mobility needs in the developing countries satisfactorily. Bus services are usually unsuitable, insufficient, and unreliable. Bus Rapid Transit (BRT) system, is an emerging public transport alternative designed to provide appropriate, low cost, and effective services, and improve mobility in both developed and developing countries. To design public transportation systems, existing constraints such as resources and budget have to be considered to serve estimated demand properly. Bus Rapid...
Congestion Pricing with Consideration of Long‐Term Effects
,
M.Sc. Thesis
Sharif University of Technology
;
Poorzahedy, Hossein
(Supervisor)
Abstract
Congestion is the inseparable part of everyday life in large transportation networks. Expansion of road networks especially in downtown area is next to impossible and it is resulting multiplicative congestion problems. Congestion imposes private and public costs. Therefore, restricting policies on road use through cordon-based or area-based pricing is proposed to reduce the negative impacts of traffic, travel demand management and optimal use of transportation systems. This would produce better resource allocation through transportation network optimization. Implementation of congestion pricing policies induces short-term and long-term effects. In this thesis, it is attempted to determine...
Travel Demand Management to Reduce Air Pollution by Network Pricing
,
M.Sc. Thesis
Sharif University of Technology
;
Poorzahedy, Hossein
(Supervisor)
Abstract
This research deals with pricing private automobiles entering a congested area in urban CBD to reduce auto-related air pollution. There are two factors affecting the pollution level: car volumes, and the weather condition. A Markov decision process is employed to find the optimal tolls and determine the prices for different states of the system, under several weather conditions. The demand for travel is elastic. It is assumed that users change modes in the short run. In longer terms, the part of the demand with shopping, recreation, or similar flexible trip purposes change the respective demand levels according to the price level. The study attempts to estimate elastic demand functions for...
An Integrated Land-Use and Transportation Model for the Evaluation of Urban Development Decisions
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossain (Supervisor)
Abstract
Land-use and transportation are inter-related, such that land-use may be used to control transportation. This study aims to design a suitable combination of the residential and service land-use on one side, and the transportation system on the other side. The model presented in this study has two external and internal levels, and its objective is to minimize the cost of residence, receiving goods and services, and transportation. The performance of any combination of spatial allocation of population and employment, as well as transportation, is evaluated by the internal level of the model which determines the interaction between population, employment, and transportation. This is done by a...
Network Reconstruction for Emergency Response Following a Major Earthquake: Definition and a Solution Algorithm
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossain (Supervisor)
Abstract
Natural phenomena, such as earthquakes, floods, and hurricanes, have been, and will be, one major source of mankind disastrous problems. Mankindinterventions to relieve this heavy pressure on humanity have been divided into four categories: mitigation, preparedness, response, and recovery. This study is in the response phase, and aims to find an optimal network to help people in the devastated part of a city, hit by a major earthquake. Such earthquakes demolish buildings over the people inside, causing them fatal harm and serious injuries. At the same time, they ruin the city infrastructures (life lines), including transportation networks, preventing flow of relief supply to reach to the...
On The Interaction Between Location-Allocation of Population-Employment and Transportation Based on Living Costs
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossein (Supervisor)
Abstract
This study is an endeavor to model the interaction between transportation and land use, as a constituent of a joint land use-network design problem defined in the context of transit oriented development (TOD). Population and employment follow a Garin-Lowry model; the endogenously determined transportation demand is administered by a joint mode choice-assignment model; and mode choice is governed by a logit model. Equilibrium of population choice of place of residence, employment choice of place of retailing, and passenger choice of mode and path, are all governed by a maximum utility principle. An algorithm is devised to reach these equilibrium states by an evolutionary process, whose engine...
An Electromagnetism-Like Algorithm to Solve Three-Dimensional Highway Alignment Problem
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossein (Supervisor)
Abstract
Road construction and maintenance constitute a significant part of country-wide infrastructure development budget each year. This indicates the importance of planning and design of individual road alignment in reducing the development cost. This study presents a meta-heuristic algorithm based on the concept of electromagnetism, which explores and finds a good route between two given points within a three-dimensional (3-D) context. It defines the region in a continuous 3-D surface, identifies initial routes, which are directed and shaped toward better positions by the help of local and global search. The final good solution is fine-tuned to produce a better alignment. The behaviour of the...
Short-Term Traffic Volume Estimation Based on Macroscopic Flow Characteristics
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossein (Supervisor)
Abstract
Traffic volume is the most important characteristic in most traffic studies, which is regularly measured by sampling methods for a given road. Traffic volume has determining effect in specifying network origin-destination demand, improvement of roads, traffic distributions over the network, improving road parameters, air pollution and in other aspects of flow in the network. There are many ways to measure traffic volume in different situations. However, most of them are expensive to implement and in cases which take a long time to do the survey, or the number of locations are excessive, the operation would not be cost-effective. In this research we investigate using macroscopic...
Integrated Road Reopening and Disaster Relief Programming: Problem Formulation and Solution Procedure
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossain (Supervisor)
Abstract
This research deals with the joint problem of reopening the roads closed after a disastrous natural event and the damaged area relief programming. While these two problems are connected to each other by the joint resources of ruins and debris removal, they are usually treated separately in the literature, and their solutions are sought in practice by the art of experienced authorities. This study formulates a dynamic tri-level integer programming problem to represent the two problems of Road Reopening and Relief, in which the crisis manager has the objective of minimizing the death tolls over a planning time interval. It identifies the roads for reopening at the first level; and the second...
Peer evaluation of multi-attribute analysis techniques: Case of a light rail transit network choice
, Article Scientia Iranica ; Volume 20, Issue 3 , 2013 , Pages 371-386 ; 10263098 (ISSN) ; Rezaei, A ; Sharif University of Technology
2013
Abstract
This paper attempts to present a method for differentiating between multi-attribute decision procedures and to identify some competent procedures for major decision problems, where a matrix of alternative-measure of effectiveness and a vector of weights for the latter are available. In this respect, several known multi-attribute analysis procedures are chosen, and the same procedures are exploited to evaluate themselves, based on some evaluation criteria. This is done from an engineering viewpoint and in the context of a transportation problem, using a real case light rail transit network choice problem for the City of Mashhad, and the results are presented. Two concepts have been proposed...
Land Use-Transportation Integrated Model to Evaluate Long-Term Impacts of Transit Oriented Development
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossein (Supervisor)
Abstract
Expansions of large urban areas, as well as increase in the rate of car ownership, has given rise to the urban traffic congestion. One of the major approach to cope with the congestion issue is named Transit Oriented Development (TOD), which will cause changes in trip departure times, route choice, mode choice, and trip destinations. TOD also affects the land use in long-run periods. The goal of this study is to clarify the long-term impacts of TOD on land use and find the appropriate transit projects in order to abate the drawbacks of changes in land us. Land use/ transportation has been the subject of many recent studies. One of the previous studies investigates land use and transportation...
Pre-crisis Planning in Transportation Networks, Considering Immediate, Short-Run and Long-Run Losses: Case Study of the 2003 Bam Earthquake
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossein (Supervisor)
Abstract
Natural disasters take many lives each year and leave many others homeless, thereby occupy governments to restore previous conditions rather than deal with progress. Iran has also a worrisome record of natural disasters, and the unpreparedness of the parties involved turn each of such event into a disaster. The purpose of this study is to estimate more accurately the outcomes of severe earthquakes, and show its effect on the decisions which are made to mitigate them. The losses are classified into three groups of immediate, short-run and long-run, which are then measured by some common quantities. Using the 2003 Bam Earthquake as a reference, these quantities are used to measure the...
Solving the Network Design Problem by Surrogate Functions and Lower and Upper Bounds on the Objective Function at Different Levels of Budget
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossein (Supervisor)
Abstract
The purpose of this research is to provide a method for finding a “good” solution to the network design problem with less computational efforts, faster than the existing conventional methods of solving this problem. Network design problem is the problem of selecting a subset of projects from a set of alternative projects so that to optimize the objective function (e.g., the total travel time in the network) subject to the set of existing constraints (e.g., budget). Due to the combinatorial and non-convex nature of the problem, its solution could be very cumbersome and time-consuming. Various methods have been proposed to solve this problem efficiently, providing good solutions at high...
A Solution for Network Design Problem by B.O.T (Build-Operate-Transfer) and Considering Uncertain Parameters of the Problem
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossain (Supervisor)
Abstract
Governments are concurrently faced with two problems in Network Development Problem (NDP): limited resources to invest, and the economic justification of the candidate projects. Public- Private Participation (PPP) is a solution for the first problem, in which Build- Operate- Transfer (BOT) is a scheme to implement this partnership.This study formulates a NDP, in which two sources of funds back projects’ construction: that of the private investor and the public budget for this purpose. The problem is seen as bi-level optimization, with the upper level dealing with the government decisions on the level of participation (from 0 to 100 percent of the project costs), and the lower level being a...