Afshin Shariat Mohaymany

Bio: Afshin Shariat Mohaymany is an academic researcher from Iran University of Science and Technology. The author has contributed to research in topics: Resource allocation & Poison control. The author has an hindex of 14, co-authored 39 publications receiving 665 citations.

Transportation network vulnerability analysis for the case of a catastrophic earthquake

Abstract: The aim of this paper is to propose a post-disaster vulnerability analysis for the designed emergency transportation networks in Tehran, an earthquake-prone metropolis in a developing country. The situation of Tehran is somewhat disheartening as it has developed haphazardly with little attention to construction and building codes, which leaves structures, transportation routes, and residents vulnerable. This paper attempts to demonstrate the challenges of trying to develop transportation vulnerability analysis in a developing country, especially one as a major population center in a geographic area prone to earthquakes. After a catastrophic earthquake in a developing country, the conventional network analysis methods may not be employed because first, the post disaster travel demand can be fundamentally altered from the usual daily travel demand and, perhaps, the forecast of the trip demand in the highly uncertain condition seems impossible. Second, the behavior of passengers may not be rational. In line with this idea, a comprehensive study on urban seismic disaster prevention and management for the greater Tehran is held in this paper. This paper proposes an approach to evaluate post-earthquake response and recovery routes by identifying redundancy-based isolation measures to find out which zones in this city are most susceptible to disruptions of the transport system due to a devastating earthquake, and which emergency response trips are most vulnerable in the super-chaotic situation after the earthquake.

GIS-based method for detecting high-crash-risk road segments using network kernel density estimation

Abstract: Identifying high-crash-risk road segments provides safety specialists with an insight to better understanding of crash patterns and enhancing road safety management. The common hotspot identification methods are not robust enough to visualize the underlying shape of crash patterns since they neglect the spatial properties of crash data. Spatial traffic accidents have the tendency to be dependent, a phenomenon known as spatial autocorrelation. Values over distance are more or less similar than expected for randomly associated observations. Modeling the spatial variations can properly be explained in terms of first- and second-order properties. The first-order properties, describe the way of varying the expected value of point pattern in space which can be due to changes in the substantial properties of the local environment, while second-order effects describe the interactive effects of events explaining on how the events are interacted. Considering the discrete nature of crash data and the limited access ...

Multimodal Feeder Network Design Problem: Ant Colony Optimization Approach

Abstract: Significant service performance capabilities of high-capacity mass transit make it a remarkable part of any large metropolitan transportation system. Unfortunately it is not feasible to provide citywide direct access to high-capacity transit. Other modes of transit are used as feeders to collect and deliver passengers to high-capacity mass transit. By using feeder lines the possibility of use of high-capacity mass transit increases because the travel demand for a more extended area can be satisfied. In this research, multiple modes with various capacities and performances are used in the feeder network design based on the minimization of user, operator, and social costs. Other approaches have only used one mode (usually bus) for designing the feeder network.

Aberrant Driving Behaviour, Risk Involvement, and Their Related Factors Among Taxi Drivers

Abstract: The current study aims to investigate the aberrant driving behaviour and risk involvement of Iranian taxi drivers. The sample comprised 405 Iranian taxi drivers, who were recruited with a cross-sectional design, using a self-completion questionnaire survey during October and November 2016. We contribute to the literature by understanding how and to what extent the socioeconomic, demographic, driving, and aberrant driving behaviours influence risk involvement (accident involvement and traffic tickets). The validated 27-item Driver Behaviour Questionnaire (DBQ) was applied to measure aberrant driving behaviour. The results from valid observations (n = 381) explored a four-factor solution (including errors, ordinary violations, lapses, and aggressive violations) of the DBQ. The results also showed that being a single driver, having a high annual driving mileage, and a high number of daily taxi trips were positively associated with accident involvement. Furthermore, there was a positive correlation between the more ordinary violations and aggressive violations and accident involvement. Establishing better training and qualification mechanisms for taxi drivers could be considered by traffic safety experts in order to reduce ordinary and aggressive violations.

Multiple criteria decision-making techniques and their applications – a review of the literature from 2000 to 2014

Abstract: Multiple criteria decision-making (MCDM) is considered as a complex decision-making (DM) tool involving both quantitative and qualitative factors. In recent years, several MCDM techniques and approaches have been suggested to choosing the optimal probable options. The purpose of this article is to systematically review the applications and methodologies of the MCDM techniques and approaches. This study reviewed a total of 393 articles published from 2000 to 2014 in more than 120 peer reviewed journals (extracted from Web of Science). According to experts’ opinion, these articles were grouped into 15 fields. Furthermore, these articles were categorised based on authors, publication date, name of journals, methods, tools, and type of research (MCDM utilising research, MCDM developing research, and MCDM proposing research). The results of this study indicated that in 2013 scholars have published articles more than in other years. In addition, the analytic hierarchy process (AHP) method in the individual tool...

Transportation network analysis

Abstract: Transportation Networks. Optimality. Cost Functions. Deterministic User Equilibrium Assignment. Stochastic User Equilibrium Assignment. Trip Table Estimation. Network Reliability. Network Design. Conclusions. References. Index.

Vulnerability and resilience of transport systems : A discussion of recent research

Abstract: The transport system is critical to the welfare of modern societies. This article provides an overview of recent research on vulnerability and resilience of transport systems. Definitions of vulnerability and resilience are formulated and discussed together with related concepts. In the increasing and extensive literature of transport vulnerability studies, two distinct traditions are identified. One tradition with roots in graph theory studies the vulnerability of transport networks based on their topological properties. The other tradition also represents the demand and supply side of the transport systems to allow for a more complete assessment of the consequences of disruptions or disasters for the users and society. The merits and drawbacks of the approaches are discussed. The concept of resilience offers a broader socio-technical perspective on the transport system’s capacity to maintain or quickly recover its function after a disruption or a disaster. The transport resilience literature is less abundant, especially concerning the post-disaster phases of response and recovery. The research on transport system vulnerability and resilience is now a mature field with a developed methodology and a large amount of research findings with large potential practical usefulness. The authors argue that more cross-disciplinary collaborations between authorities, operators and researchers would be desirable to transform this knowledge into practical strategies to strengthen the resilience of the transport system.

Planning, operation, and control of bus transport systems: A literature review

Abstract: The efficiency of a transport system depends on several elements, such as available technology, governmental policies, the planning process, and control strategies. Indeed, the interaction between these elements is quite complex, leading to intractable decision making problems. The planning process and real-time control strategies have been widely studied in recent years, and there are several practical implementations with promising results. In this paper, we review the literature on Transit Network Planning problems and real-time control strategies suitable to bus transport systems. Our goal is to present a comprehensive review, emphasizing recent studies as well as works not addressed in previous reviews.