Papers by mohammad maghrour zefreh
Sustainability, 2021
External costs that are associated with air pollution, climate change linked to greenhouse gas em... more External costs that are associated with air pollution, climate change linked to greenhouse gas emissions (GHG), and noise are among the most important environmental externalities that are generated by road transport, which have been well monetized. This paper theoretically investigates the effects of different traffic conditions on the environmental external costs of urban roads where traffic flow is more complicated than un-interrupted traffic flows. A Monte Carlo method is used to theoretically simulate traffic speed in different traffic conditions. Subsequently, the emitted carbon dioxide (CO2), nitrogen oxides (NOx), carbon monoxide (CO), particulate matter (PM), sulfur dioxide (SO2), and noise were estimated in each of the theoretically simulated traffic conditions. Finally, the environmental external costs in each traffic condition were calculated taking the EU average costs values into account. The results showed that, when compared to free-flow condition, the total air pollu...
Proceedings of the Asia-Pacific Conference on Intelligent Medical 2018 & International Conference on Transportation and Traffic Engineering 2018 on - APCIM & ICTTE 2018, 2018
Road transport generates negative externalities including air pollution, congestion, accidents, n... more Road transport generates negative externalities including air pollution, congestion, accidents, noise and climate change linked to Greenhouse Gas emissions (GHG). In the current paper, the role of vehicle's internal combustion (IC) engine type in the environmental external costs of road transport has been highlighted such that the potential air pollutants and GHG emissions of the EURO IV Gasoline passenger cars and EURO IV Diesel passenger cars have been compared to each other in 1 km of a theoretical urban road and Highway. The results showed that, compared to Gasoline passenger car, the external cost (€ in 2010 prices) associated with air pollution and GHG emissions has been increased in Diesel passenger car by 78.65 % and 48.75 % in 1km of Highway and Urban road respectively. The results suggest imposing different tax rates (as an internalizing tool) for different vehicle classes since they would considerably produce different amount of externalities at least in the case of air pollution and GHG emissions. Moreover, the results implied the fact that not just the different IC engines had the influence on environmental externalities but also road type had a considerable impact on the externalities especially in the case of the externalities associated with NOx emissions.
TRANSBALTICA XI: Transportation Science and Technology, 2020
The modern transportation system is walking step by step toward automation. As automated technolo... more The modern transportation system is walking step by step toward automation. As automated technology continues to develop, the new technology offers a considerable opportunity to enhance public transportation systems especially in the development and promotion of the sustainable mobility concepts. The driverless public transportation can only become a reality if they are fully accepted by their target/potential users. Hence, user acceptance studies are of great importance since they will investigate what factors can influence this acceptance. In the current study, the relationship between acceptance of driverless public transportation (PT) and PT passengers’ personal characteristics has been examined using Fisher’s Exact Test. The results showed that the user acceptance of driverless PT has a significant relationship with the health condition of the passengers, frequency of PT usage, age, level of education and the motivation of the trip made by public transportation.
Proceedings of the 5th International Conference on Smart Cities and Green ICT Systems, 2016
In recent years, road transport models have developed for better estimation of road traffic emiss... more In recent years, road transport models have developed for better estimation of road traffic emissions with higher and higher temporal and spatial resolution, to be used as a tool in air quality management for the better living. Road transport related emission models are becoming more and more complex. In this paper, the key research question is how the improvement in modelling influences the results? The authors compared three different macro emission modelling system with the dataset of Hungary for 2010. One must notice that more precise model has larger data requirement. Firstly, the consumption-based model was run with 31 needed input data secondly, EURO standard based model was run with 261 needed data and finally, speed dependent model was run with 1060 needed input data. According to the results, it can be stated that a more complex model could cause significant differences in emission compared to simpler one. The differences can be caused by old Hungarian vehicle fleet or differences in estimation error.
Period. Polytech. Transp. Eng. M. A. Saif, M. M. Zefreh, A. Torok Abstract Accessibility is one o... more Period. Polytech. Transp. Eng. M. A. Saif, M. M. Zefreh, A. Torok Abstract Accessibility is one of the most important outcomes of the transportation system. Public transport can be more attractive by providing "Door to door mobility" and development of transportation services is an important factor of social quality. Public transport accessibility has gained vital importance in designing and evaluating the transit system in terms of mobility and sustainability. Apart from the transport system itself, public transport accessibility has the considerable impact on life satisfaction in the form of perceived accessibility. Moreover, researchers have revealed several impact and correlation of provision of public transport accessibility to the environment and daily life which would have a noticeable impact on public health and other aspects of public daily life. Furthermore, the correlation between public transport accessibility and job opportunities has attracted the researchers...
Journal of Advanced Transportation, 2018
Road traffic noise is one of the most relevant sources in the environmental noise pollution of th... more Road traffic noise is one of the most relevant sources in the environmental noise pollution of the urban areas where dynamics of the traffic flow are much more complicated than uninterrupted traffic flows. It is evident that different traffic conditions would play the role in the urban traffic flow considering the dynamic nature of the traffic flow on one hand and presence of traffic lights, roundabouts, etc. on the other hand. The main aim of the current paper is to investigate the effect of different traffic conditions on urban road traffic noise. To do so, different traffic conditions have been theoretically generated by the Monte Carlo Simulation technique following the distribution of traffic speed in the urban roads. The “ASJ RTN-Model” has been considered as a base road traffic noise prediction model which would deal with different traffic conditions including steady and nonsteady traffic flow that would cover the urban traffic flow conditions properly. Having generated the v...
Proceedings of the Institution of Civil Engineers - Transport, 2020
Road pricing is an efficient instrument to regulate use of roads. In Budapest, Hungary, only cord... more Road pricing is an efficient instrument to regulate use of roads. In Budapest, Hungary, only cordon pricing has been investigated in detail. This paper reports on a study of the implications of applying different road pricing schemes in the city using a macroscopic traffic model. Firstly, the functional relationship between pricing schemes and road transport demand was investigated. Secondly, the implications of applying road pricing schemes on travel demand, travel time, delay time, average speed and carbon dioxide emissions of road users inside and outside of the pricing area, as well as revenues generated by applying the schemes, were studied. The results revealed that a time-based system showed the best performance inside the pricing area. However, it generated heavy congestion on non-priced roads bordering the pricing area, which would increase travel times, delay times and carbon dioxide emissions and would decrease average travel speeds on the entire network. The cordon-based...
Transport, 2020
Fundamental diagram, a graphical representation of the relationship among traffic flow, speed, an... more Fundamental diagram, a graphical representation of the relationship among traffic flow, speed, and density, has been the foundation of traffic flow theory and transportation engineering for many years. Underlying a fundamental diagram is the relation between traffic speed and density, which serves as the basis to understand system dynamics. Empirical observations of the traffic speed versus traffic density show a wide-scattering of traffic speeds over a certain level of density, which would form a speed distribution over a certain level of density. The main aim of the current research is to study on the distribution of traffic speed in different traffic conditions in the urban roads since the distribution of traffic speed is necessary for many traffic engineering applications including generating traffic in micro-simulation systems. To do so, the traffic stream is videotaped at various locations in the city of Budapest (Hungary). The recorded videos were analysed by traffic engineer...
Measurement, 2018
Abstract The data derived from loop detectors are of great importance in terms of traffic monitor... more Abstract The data derived from loop detectors are of great importance in terms of traffic monitoring and analysis. These data may contain many holes or incorrect values due to equipment malfunctions and communication faults that may produce unreliable results. These holes (missing samples) or incorrect values (bad samples) might be problematic for any algorithm that uses the data for analysis. In this paper, a method is described that detects bad data samples gathered by the loop detectors and imputes the best available samples in order to fill the holes caused by the bad declared samples. The diagnostics algorithm proposed in this paper is based on the statistical analysis. Unlike the previous approaches, this algorithm considers the time series of many samples, rather than basing decisions on single samples. The imputation algorithm proposed in this paper uses the “good” declared samples from the historical data of the investigated loop detector to fill the holes caused by the bad declared samples. This detection and imputation process allows the algorithms that use loop data to perform analysis without requiring them to compensate for missing or incorrect data samples.
Transport and Telecommunication Journal, 2019
Automated vehicles (AVs) are one of the emerging technologies that can perform the driving task t... more Automated vehicles (AVs) are one of the emerging technologies that can perform the driving task themselves. The market penetration of AVs is expected to get growth in the close future. Therefore, it is crucial to have an overall clue on how they play the role in the road transportation sector. Automation might be assumed to have a beneficial impact on many aspects related to road transportation. The current paper attempts to investigate this rough assumption by reviewing the literature on the potential effects of automated vehicles on road transportation. A comprehensive look at the overall potential effects of automated vehicles will show the entire picture, and not just a cropped portion of that, to the researchers, decision makers, and practitioners and helps them to identify the negative and positive effects as well as challenges and uncertainties towards this new technology. In this paper, literature findings on the potential effects of automated vehicles on traffic flow, pedes...
Periodica Polytechnica Transportation Engineering, 2018
Accessibility is one of the most important outcomes of the transportation system. Public transpor... more Accessibility is one of the most important outcomes of the transportation system. Public transport can be more attractive by providing "Door to door mobility" and development of transportation services is an important factor of social quality. Public transport accessibility has gained vital importance in designing and evaluating the transit system in terms of mobility and sustainability. Apart from the transport system itself, public transport accessibility has the considerable impact on life satisfaction in the form of perceived accessibility. Moreover, researchers have revealed several impact and correlation of provision of public transport accessibility to the environment and daily life which would have a noticeable impact on public health and other aspects of public daily life. Furthermore, the correlation between public transport accessibility and job opportunities has attracted the researchers' attention in the literature. Also, public participation in social act...
Acta Technica Jaurinensis, 2016
Vehicles speed distribution is an important input parameter in lots of issues, such as kinematica... more Vehicles speed distribution is an important input parameter in lots of issues, such as kinematical traffic simulation model, road design, speed limit evaluation, road traffic noise prediction or vehicles emission estimation. In this paper, a new approach has been presented in which the speed is randomly generated according to different speed distributions. Later on, these distributions were used as the basis of emission estimation. These different distributions were chosen according to the contextual traffic situation (free flow, pulsed accelerated flow, intersection, congestion, etc.) and were assigned to the fundamental diagram. The study of the effect of different speed distributions on the resulting emission level has been performed. The considerable difference in the emission models related to Log-normal distribution as well as exponential, chi-square and equal distribution to normal Gaussian distribution implies that these different traffic conditions will have a considerable effect on emission and will show the need for applying multimodal speed distribution in macro emission estimation rather than unimodal distribution. It should also be mentioned that this result may lead to the chance of revising the simulation software in further studies.
MATEC Web of Conferences, 2016
Underlying a fundamental diagram is a relation between traffic speed and density which roughly co... more Underlying a fundamental diagram is a relation between traffic speed and density which roughly corresponds to drivers' speed choices under varying car-following distances. Stochastic and deterministic models are mainly two different categories of speed-density models. The advantages of deterministic models are their mathematical simplicity and analytical tractability though their results will show just the average parameters. Although the stochastic models may represent more accurate results taking uncertainty into account, they are often hard to use and analytically not tractable. The aim of this paper is to investigate the possibility of presenting a model which is neither completely deterministic nor completely stochastic but easy to use and understand which incorporates different traffic conditions and speed distributions. Monte Carlo Method has been used to generate different speed distributions based on different traffic conditions and consequently generating their relevant densities. Surveying the relation between the mentioned speed distributions and the obtained densities kept the chance of presenting a model which is neither completely deterministic nor completely stochastic but easy to use and understand which incorporates different traffic conditions and speed distributions.
PROMET - Traffic&Transportation, 2017
This paper analyses the effect of supporting the public transport policy based on intersection co... more This paper analyses the effect of supporting the public transport policy based on intersection controlling with the aim of tram priority in Budapest, as a case study. The hypothesis related to this study was that the support of public transport is only viable when the marginal benefit of public transport is higher than the marginal cost of individual transport. Therefore, the real costs of this support for the society were estimated. This study revealed that by applying this policy, the waiting time at intersections and CO2 emission-related costs have increased by about 13.7% and 14.2%, respectively. Besides, the estimated monetary gain of tram users would be 17,800 euro on a daily level total by applying the mentioned policy.
Periodica Polytechnica Transportation Engineering, 2016
The sudden maneuver of shared taxi through lanes in order to pickup and drop-off passengers and a... more The sudden maneuver of shared taxi through lanes in order to pickup and drop-off passengers and asking their destinations-due to lack of designated stop locations-may lead to disorder in traffic flow. The main hypothesis in this research was that shared taxis sudden maneuvers and lane changings have negative effects on traffic flow characteristics and subsequently, suppressing these maneuvers will improve traffic flow characteristics. For this purpose, a study was done on a path in the city of Isfahan in Iran. First the investigated path simulated without shared taxi sudden maneuvers and then the outputs of this simulation were compared to the real measurement data. By this comparison, some differences were observed. The shared taxis maneuvers were added to simulation to see if the observed difference can be lowered. By comparing the outputs of these two simulations to the real situation parameters, the considerable negative effect of this maneuvers was recognized. After observing of the mentioned maneuvers negative effect, an innovative solution-allocating a line to shared taxis and High Occupancy Vehicles-was added to suppress shared taxi maneuvers in order to improve traffic flow characteristics. By applying this scenario on current situation delay of traffic flow and delay of shared taxis decreased from 458.48 sec. to 383.01 sec. and from 506 sec. to 450 sec. respectively. Besides, traffic flow and the number of shared taxis increased from 11986 to 12980 and 663 to 718 vehicle per hour respectively.
2015 International Conference on Models and Technologies for Intelligent Transportation Systems (MT-ITS), 2015
In Iran, shared taxis are playing significant role in public transport. Maneuver of shared taxi t... more In Iran, shared taxis are playing significant role in public transport. Maneuver of shared taxi through lanes in order to pick-up and drop-off passengers and asking their destinations may lead to disorder in traffic flow. In order to investigate the effect of these maneuvers (or sudden lane changing) on traffic flow, it is essential to simulate these maneuvers on the existing roads in intelligent traffic simulator software. In this research Aimsun software was selected as a traffic modelling software. The selected path was simulated twice. First it has been simulated with all geometrical characteristics of path and all passing vehicles, without maneuvers of shared taxis. Travel time parameter of vehicles was selected to evaluate the validity of this simulation. After observing errors between simulation and real time measurement, maneuver of shared taxis around stop areas was added to the previous simulation. It was observed that simulating the maneuvers of shared taxi decreased the error significantly. By comparing these two travel time the considerable effect of these maneuvers was recognized around 16.95% on travel time of passing traffic flow in this path.
Uploads
Papers by mohammad maghrour zefreh