پژوهشنامه حمل و نقل
سال نوزدهم شماره 2 (پیاپی 71، تابستان 1401)

One of the important issues in supply chain management, vehicle routing and scheduling problem has always been which has so far attracted considerable attention from researchers. This paper attempts to optimize routing and scheduling for a heterogeneous transportation system with considering stochastic supply and demand, various traffic conditions, maximum continuous driving time constraint and soft time window constraint of each customer delivery. The consideration of pollution in routing decisions gives rise to a new routing framework where measures of the environmental implications are traded off with business performance measures. Also, the aim of this study is to minimize energy consumption and to maximize customer satisfaction, simultaneously. At first, this problem is presented in the form of a multi-objective linear programming model and then a novel integrated approach is proposed based on combination of chance constraint method and goal programming. Finally, the results of numerical example are analyzed with sensitivity analysis.
.

Road speed management is one of the most important and effective measures to prevent and reduce the severity of traffic accidents and injuries to road users. Because a significant proportion of the fatalities and injuries resulting from road accidents are permitted due to speeding. Therefore, as a case study of Urmia-Ashnoye axis in West Azarbaijan province was investigated using RSP. Traffic information was extracted from online traffic systems related to in 2017. The results show that the arcs can be divided into three categories: Sections 1 to 5, with car speeds averaging 35 km / h, and Sections 10-6 with car speeds averaging 45 km / h 14 that cars have an average speed of 50 km / h. All of these speeds were taken while the track speed was 110 km / h, indicating that the arches had steep slopes, and in sections 1-5 that had the most deceleration there was a more dangerous arc in terms of safety and the likelihood of accidents involving speed drivers. Have reduced themselves to a great extent. Finally, it is recommended to use an average speed of 85% of the cars in those arches to determine the speed in the arches.

This paper aims to develop a method to detect dangerous situations for each vehicle based on microscopic traffic data for intelligent vehicles. Here, surrogate safety measures (SSMs) would be applied. Each SSM has unique characteristics and if we could use the advantages of different SSM simultaneously, then the efficiency of intelligent vehicles might be increased. For this purpose, Fuzzy Inference System (FIS) is applied to develop a Combined Surrogate Safety Measure (CSSM). In order to avoid complicating the issue, only rear-end collisions are considered. Microscopic traffic data collected in Modares highway of Tehran is used to develop FIS. Finally, the CSSM results are compared by each SSM statistically. Based on the results, it can be declared that FIS can be helpful to calculate the rear-end collision probability by using different SSMs. This achievement can be useful in promoting the efficiency of autonomous vehicles.

The process of estimating the origin and destination matrices is that first there is an initial matrix that is given to the dynamic assignment network with the help of transims software so that the dynamic volumes are obtained and compared with the observed volumes in reality and their differences are corrected in later steps. Most studies to date have focused on providing new methods for problem solving, and due to the complexities of discussing the implementation of origin and destination matrix estimation in the real environment, less attention has been paid to it. In this research, modeling of this bi-level process in the form of a case study of Waterbury City (due to the availability of data and congested traffic network), dynamic assignment using transims software that is powerful in various transportation discussions and also has the ability to make changes to the program. The origin and destination matrix estimation in saturation conditions is performed using the Kalman filter algorithm and the least squares error approach (widely used and powerful in large-scale and saturation networks), as well as coding the entire origin and destination matrix estimation process. In the language of C++, is the innovation of this research. At the end of the iterative steps, the amount of arc volume error to confirm the process of estimating the source and destination matrix is obtained using the least squares error method, which is used to apply the process confirmation condition, the optimal source and destination matrix is obtained that close The results of the volumes observed in the real environment

In this study the effect of short and long term aging on the properties of recycled asphalt containing high percentage of reclaimed asphalt pavement (RAP) and rejuvenated by different dosages of waste cooking oil has been investigated. The coarse fraction of virgin aggregates was replaced with RAP, and the mixtures were rejuvenated by adding 0, 4, 7 and 10% (by the weight of total binder) of waste engine oil. The mixtures were short and long term aged and the volumetric properties, Marshall stability and flow and weight loss in Cantabro test were evaluated for the unaged and aged mixtures. Results reveal that the mixture containing RAP and without rejuvenation has higher VMA, Marshall stability, flow and weight loss in Cantabro test than the mixture made of virgin aggregates. The properties decrease with increasing oil content. Short term and long term ageing result in increase of VMA, Marshall stability and weight loss, and decrease of flow, with higher changes by long term ageing. Evaluation of ageing indices reveals that the effect of ageing increases with increasing oil content.

Road transport in the country with more than 90% of the transportation share is the most important transportation sector. The main objective of this paper is to estimate the number and distribution of inter-city road freight fleet and its optimal distribution in the provinces of Fars and Khuzestan, which has had a larger share in the transportation of the country. First, there was a general discussion of the problem and the importance of estimating the number and distribution of freight fleet, and then, by examining past studies, demand for transportation and demand estimation patterns were explained, and a multivariate decision making model with multi-objective integer programming approach was used to solve the problem. The problem model is composed of two objective functions, which minimizes the total cost of the system to the first objective function. These costs consist of two fixed and variable costs, which are set up costs and linear costs of sending products from distribution centers to customers, and in the second objective function, the total amount of time the products are sent from the distribution centers to customers is minimized. The required data were collected into the problem model and the model was implemented using Gams software. It was determined that for the two research provinces (Fars and Khuzestan provinces) there are 5550 required fleet units, Of these, 2700 cargo fleet units should be distributed in Fars province and 2850 cargo fleet units in Khuzestan province.

In our rapidly urbanizing world where the city dwellers need to travel either short or long distances by their vehicles, road safety has become at the heart of the attention of authorities in both developed and developing countries. As automobile becomes affordable nowadays, the number of personal cars increasing, and the expectancy of the car crash is rising spontaneously. The chief reasons for road incidents and car crashes can be investigated among road, vehicle, and drivers simultaneously. In this study, we only concentrate on the effects of vehicles on the severity of accidents. At first and by utilizing multi attribute decision making techniques, the ranking of each vehicle by models that was the culprit of incidence was determined. By analyzing the results, it appeared that trucks carrying dangerous and flammable materials, bicycles and motorbike s have dedicated the highest crash severity to themselves. Though the most common road accident was among those cars owned by someone, in the second part of the study, the severity of car crashes investigated among personal cars. Vehicle ranking performed under two weighting scenarios for those cars with a higher accident frequency, and the final rank was determined for the severity of road accidents by employing the Copeland method. Furthermore, the effect of driver age variable was evaluated using repeated-measures analysis of variance and it found that driver age also had an impact on the probability of casualty or fatality occurrence.

A large number of studies have been devoted to the study of factors affecting knowledge management. However, little is known about the impact of knowledge management factors on technology development. The purpose of this study is to investigate the impact of knowledge management factors on the development of technologies with a focus on transit development criteria.The present study is part of the correlation-survey method group. In order to collect data, a standard questionnaire was developed. The statistical population includes a team of experts consisting of each studied section of the transit transportation sector in Iran. The selection of the research sample in the present study is saturated and purposeful. (104 questionnaires were collected). To test the research hypotheses, structural equation modeling was used according to a two-step approach using Smart-PLS version 2 software.The results of the above hypotheses showed that knowledge management factors (knowledge acquisition, knowledge sharing, knowledge application, knowledge protection) with perceived usefulness, perceived ease of use affect the development of technologies focusing on transit development criteria. In general, the use of new tools can reduce problems in the field of work, including transit.

High plasticity clay soils are one of the problematic soils for engineering projects, especially for road construction. Electro-osmosis is one of the methods for improving the characteristics of the soft and fine grained soils. In this method applying the electric field cause changes in microstructure of the soil and modify the physical and chemical properties of the soil. Injecting chemical solution into soil during the electro-osmosis process adopted for enhance the efficiency of the treatment in recent years. The effect of injection of strontium solutions on chemical and geotechnical characteristics of soil was investigated. A layer of the soil was impacted in a tank for obtaining density and field moisture content. Direct current was applied through the soil under voltage gradients of 0.5, 1, and 2 (V/cm) for periods of 7, 14, and 28 days, with and without the injection of strontium solution. Stainless steel electrode was exerted for treatment. The results demonstrated the increases in compressive strength and reduction of the moisture content of the soil. From the results it is noted that injecting strontium increases the compressive strength and volume of drained water compare to electro-osmosis process in absence of strontium. Chemical analysis of the soil before and after the treatment identifies the ionic migration, ionic exchanges and changes in chemical composition of the soil. These chemical changes lead to changes in structure and properties of the soil. The scanning electron microscopy (SEM) images exhibited the changes of the microstructures including flocculation and agglomeration and confirm the validity of physical results. At last, the result of California bearing ratio (CBR) showed that electro osmosis chemical treatment is feasible method to increase the properties of the soil to meet the requirements for subgrade constructions.

Evacuation is the transfer of population from one area to another in a limited time during disasters. The main goal of this process is to transfer people out of the risky area as quickly as possible to reduce casualties. Therefore applying management policies to reduce the duration of evacuation can play a vital role in minimizing the negative effects of crises. This paper aims to investigate the impact of some management policies such as contraflowing, determining the optimal evacuation routes and evacuation phasing in Sioux Falls network and the network performance after applying the proposed policies. Among the contributions of this paper can be mentioned that the previous models are often based on static traffic assignment, conventional mathematical models and heuristic methods in which traffic conditions are considered constant during the simulation period. However, due to the dynamic and unstable nature of the emergency evacuation process, dynamic traffic assignment and traffic simulation tools can be considered as a valuable alternative to develop suitable and dynamic emergency evacuation planning to facilitate the decision-making process to determine optimal measures. Therefore, the emergency evacuation process for a case study of the Sioux Falls network is simulated in Visum as a computer simulation software and the objective function is to minimize the time required for emergency evacuation. After simulating different scenarios, the research findings indicate that the volume of demand and phasing of evacuation are among the factors affecting the duration of emergency evacuation. Also, a reduction of network evacuation time by 10 to 30% was observed after the implementation of the proposed policies with different demand volumes and emergency evacuation phasing. Finally, it can be seen that changes in the amount of evacuation demand lead to more changes in the amount of reduction in evacuation time than the type of demand distribution function.

Existence research for to evaluate the effectiveness of a series of Countermeasures in reduction crashes on the Malayer-Jokar axis in Hamadan province. In this axis, in 2015, a series of Countermeasures have been implemented during three months. To determine the effectiveness of the set of Countermeasures, Crashes data were used 19 months before and 19 months after the implementation of these Countermeasures. Due to its high efficiency in estimating the expected accidents without implementing Countermeasures and also eliminating the phenomenon of regression, the business method was used to average. The high accuracy of this method is due to the use of safety performance function (SPF) in order to logically estimate the frequency of crashes in the period before the Countermeasures. A crash prediction model was used using AASHTO (2010). Using this tool and predicting crashes before and after the implementation of Countermeasures, as well as the calculation of the expected number of crashes in the before and after periods, the effectiveness of safety was calculated. The results showed that the combination of these Countermeasures reduced the crashes by 4 percent. Although the significant assessment of this value showed that it is not significant at the 90 percent confidence level, the result is still valid, and this small amount of accident reduction, as the type of collisions observed in the after period has shown, is most likely due to the fact that Some Countermeasures have led to a reduction in certain types of crashes and an increase in other specific types.

Ballast materials play a very important role in rail tracks, the most important of which is the distribution of stresses to the bottom layers and the provision of proper elasticity and drainage. At the same time, one of the main problems of these materials is particles breakage due to dynamic transit loads as well as tamping operations, which over time, especially for weaker rocks, lead to high fouling and the need for frequent maintenance and repair. One of the proven solutions to increase the service life of ballast materials and reduce the maintenance problems caused by it, is to add an optimal percentage of TDA to the ballast, which helps to improve the abrasion behavior and durability of the material and causes less particles breakage. In this paper, the behavior of ballast materials mixed with TDA is numerically investigated using two-dimensional simulation of ballast box test with discrete element approach. Using this numerical modeling in PFC software, which has been validated by actual laboratory study of ballast box test, the effects of increasing axial load (different stress levels) and operating speed (different loading frequencies) are evaluated by performing a parametric study within the optimal percentage range. Based on this, the optimal mixing percentage between ballast and TDA materials in different stress and frequency conditions has been determined. The results showed that the stress level has a very high effect on the results, while the effect of frequency is much lower. According to the results, also 5 to a maximum of 10% by weight of TDA can be proposed as the optimal mixing percentage both in terms of settlement and particles breakage.

In general, each supply chain consists of three main stages of procurement, production and distribution. The use of the cross-docking system is a new strategy at the distribution stage to improve customer response time by moving products directly from pickup trucks to delivery trucks. Generally, for an activity to be done both machine and human resources are needed. Many researchers have already developed numerous planning methods for cross-docking systems, but human resource constraints have largely ignored. In this paper, for the first time, we examine the problem of truck scheduling in multi-door cross-dock considering the learning effects and the deterioration of tasks to fill the gap between theoretical planning models and what is happening in the real world. We have proposed a mixed integer programming model for this problem. According to the research literature, with increasing the size of the problem, the complexity of integer programming model is expanding rapidly so that the exact methods can hardly achieve the optimal solution. To solve large-scale problems, five meta-heuristic algorithms are used including Genetic Algorithms (GA), Imperial Competitive Algorithm (ICA), Keshtel Algorithm (KA), and Social Engineering Optimization (SEO). Finally, the numerical results obtained from all meta-heuristic algorithms are analyzed. We compare the meta- heuristic algorithms based on the best, average, Rpd and time criteria. As a result, the SEO and KA algorithm performed better than the other algorithms in terms of solution quality.

Bridges by any design, and any materials, signs of wear will be appear sooner or later, but several factors such as climate situation, flood or earthquake, increasing in overloading, design quality and performance and kinds of materials effect on kind and rate of this wear and development rate. Regardless to these factors can cause decreasing useful life of structures and/or their destruction. Base on critical role of bridges in civil structures and also possibility of destruction of each bridge from civil structure view is necessary. In this research we investigate role of Babolsar bridges and their effectiveness on civil structure in this city. In order to these factors such as cost of destruction, environmental losses, the importance of road and death caused by the destruction of bridges were investigated. And finally base on estimating all parameters by VIKOR multi criteria decision method that is a modern methods in multi criteria decision, use priorities main bridges in Babolsar from urban structure. Obtained results from evaluating bridge's situation, show that first bridge of this city from urban structure is very important and must be considered carefully and should be repair and maintenance priory.

The polished stone value test is a very useful test for measuring the micro-texture of different aggregates and evaluating their resistance to long term abrasion. The micro-texture of aggregates plays an important role in providing the frictional resistance of pavement, and by selecting suitable aggregates, the safety of roads can be improved significantly i.e. conducting this test alongside other tests on aggregates gives an insight to pavement engineer to select suitable aggregates stock according to project circumstances so that the skid resistance of final pavement can be guaranteed. In this paper, the method of PSV test, according to European standards, is explained and the relationship between the polished stone value and the results of other tests of aggregates is investigated. In addition, the polishing test was performed on several types of typical aggregates used in road construction from all over Iran. The results showed that majority of aggregates had a polished stone value higher than 30.

Roller compacted concrete pavement (RCCP) is a zero-slump and stiff-dry mixture which is usually placed with an asphalt paver and compacted by conventional vibratory roller compactors to achieve the required density. RCCP consistently has a slightly lower cement content than conventional concretes of similar strength. Nowadays, RCCP is used for any type of industrial or heavy-duty pavement and has advantages including cost saving as a result of the construction method and the increased placement speed of the pavement. Therefore, the use of RCCP pavement has become more and more popular in recent years. There are numerous studies on the mechanical properties of fibre reinforced focused on cement paste and normal concrete. However, our understanding of what exactly happens when hybrid fibres used to reinforce RCCP mixes with respect to fracture toughness is quite limited. Accordingly, in this study, three point bending test was carried out on mono and hybrid fibre-reinforced RCCP based on modified two-parameter model to determine the value of Mode I plane-strain fracture toughness of fibre-reinforced RCCP by considering possibility of crack deflection during its propagation through modified two-parameter fracture model. Finally, it can be observed that, for great amount of fracture angle, the application of Two-parameter fracture model instead of modified Two-parameter fracture model cause to an overestimation of the fracture toughness values.

The performance properties of bitumen can be improved by using several modifiers, including: polyphosphoric acid (PPA), semi-hot asphalt mixers (WMA) and styrene butadiene rubber (SBR). The present study evaluated the effect of PPA and WMA additives on the rheological behavior of SBR modified bitumen. Modified SBR / PPA and SBR / PPA / WMA bitumen were subjected to rotational viscosity, dynamic shear rheometer, multiple stress and creep recovery (MSCR) and linear slope sweep (LAS) tests. Based on the results of MSCR test at both stress levels, modification of the base bitumen by SBR, PPA and WMA additives improves the permanent deformation performance of the main bitumen. The results of LAS test showed that the use of SBR and WMA additives improves the fatigue life of bitumen. Also, by adding PPA, the fatigue life of SBR modified bitumen is increased. While the fatigue life is longer than the original bitumen. Among warm additives, Sasobit has a better effect on increasing the performance of bitumen.