فصلنامه مهندسی حمل و نقل
سال چهاردهم شماره 2 (پیاپی 55، زمستان 1401)

Surrogate safety measure (SSM) plays a key role in early safety evaluation. Previous research has indicated potential associations between SSM and road crashes. Several attempts have been made to develop SSM. Most studies in the field of SSM have only focused on rear-end conflicts in witch the two vehicles move in a just one lane. The principal objective of this paper was to develop a new area-based SSM (ASSM) which can take into account the two-dimensional movement of vehicles. ASSM provides a novel approach to quantifying safety. The two-dimensional hypothetical areas around the vehicle that are required for the safe movement are introduced as the influence area. The mathematical equation of the influence area is derived as a function of vehicle speed, and then ASSM could be calculated by examining the extent of overlap and intersection of the influence areas of different vehicles at any given time. In this study, techniques for ASSM were developed and applied to real-world traffic data (NGSIM). The findings indicated that there was a positive relationship between ASSM and the time of the driver's decision to change his driving position to avoid a collision. The findings can contribute to a better understanding of human driving behavior in critical situation.

With recent technological developments in the mining industry, the issue of physical asset management has become more important. Asset management in the mining industry has a key role to achieve production goals and increase competitiveness in the market. Reliability is one of the key indicators of asset management. Reliability is a function of the failures time and various risk factors such as environmental and operational conditions. One of the most widely used methods for investigating the relationship between the risk factors and reliability is the proportional hazard regression model. The regression coefficients can be estimated using two approaches, i.e. parametric and semi-parametric. In this paper, the failure data of a dump truck in the Sungun copper mine is analyzed using both semi-parametric and parametric approaches. The results show that the obtained estimates of both approaches were close to each other, according to Akaike Information Criterion (AIC), the Weibull parametric model is more efficient than the semi-parametric model at describing the reliability and hazard rate. In addition, it is found that road condition; operator skill, ambient temperature, and haulage distance have a significant effect on the hazard rate of the dump truck. This analysis is applied to maintenance management to keep the reliability of the dump truck at an acceptable level.

Among the several definitions for the resilience of transport networks, this paper deals with the (WIPW). WIPW is an innovative metric for measuring the resilience of transport networks. Due to the uncertainty in occurrence time of the disruptive events in the pre-crisis stage, in this paper, based on two new indicators: (1) time and (2) the form of the time-resilience diagram, a coefficient called the strategy implementation efficiency E (λi) is presented and using it, the (WIPW) is modified. At the end of the paper, a numerical example is provided, in the example, 9 different portfolios referred to as (R), (B), (R + B), (R ̃), (B ̃), (R ̃ + B ̃), (R*), (B*) and (R* + B*), are selected and for all the portfolios E (λi), (WIPW) and the modified () are compared. The results showed that if the optimal portfolio is selected based on WIPW and WIPW the R, and (R ̃) is selected as optimal portfolio respectively. Comparison of the selected bridges in R and R ̃ shows that the L-M Bridge in R has been replaced by G-H in R ̃. The replacement of these two bridges changed the implementation time index from 1.1128 for R to 1.1643 for R ̃ and the diagram form index from 1.0201 for R to 1.0213 for R ̃ and Finally, the implementation efficiency will be improved from 1.1352 for R to 1.1852 for R ̃.

Semi-rigid asphalt, or porous asphalt impregnated with cement or cement mortar and quicksand is an asphalt mixture with a very low fine grain and a high porosity percentage (about 20%) that is filled with cement and quicksand mortar. This type of asphalt is a flexible and durable mixture and a suitable procedure in terms of providing friction and reducing noise for road surfaces. Using the appropriate percentage of bitumen in the mixture, it can be used in areas with different temperatures. Semi-rigid asphalt is less susceptive to heat than conventional asphalt concrete. To evaluate this type of mixture, samples of a porous asphalt mixture with different percentages of cement-sand slurry (0%, 25%, 50% and 75%) were impregnated and Marshall resistance tests, dynamic creep, resilience coefficient, fatigue and moisture susceptibility was performed on them. The results show that on average, with increasing the percentage of cement-sand slurry in semi-rigid pavement, moisture susceptibility, fatigue and creep decreases by ،5%, 8% and 12%, respectively, and the Marshall resistance parameters and resilience coefficient increase by 8% and 33%, respectively. Also, with increasing the percentage of cement sand slurry in semi-rigid pavement, the amount of water and fluid absorption decreases and the amount of actual specific gravity of the sample increases. In fact, it can be said that the percentage of cement sand slurry in semi-rigid pavements is a very effective parameter on the performance of this pavement. In addition, the results show that by converting flexible asphalt pavement to semi-rigid pavement by injection of cement-sand slurry in porous asphalt cavities with granulation and optimal bitumen percentage (C granulation and 4% bitumen), respectively, the resilience modulus parameters, fatigue, creep, moisture susceptibility and Marshall resistance improved by approximately 5%, 62%, 60%, 167 and 21%; Therefore, by converting flexible pavement to semi-rigid pavement, performance parameters are improved.

Ignoring the way pilgrims enter and leave on occasions can lead to irreparable damage in places of pilgrimage. This phenomenon is more sensitive in historical contexts. Introducing the appropriate operating framework and design arrangements in historical contexts in order to properly manage the population in normal days and occasions, the main purpose of the present study was to explain and discuss event-based scenarios by logical reasoning. Therefore, the proposed framework, appropriate to the context and conditions of the historical context of Najaf, was obtained by reviewing concepts related to population dynamics and fluid models that can be generalized to human behaviors and previous scenarios of movement and activity. According to the research results, the management of human populations in places where such gatherings are formed, requires simultaneous attention to the physical dimensions of the place and its time categories on the one hand and the dynamics of the mental space of population groups and immediate and unpredictable decisions of users. For management based on a model consisting of five factors: population input and output, population absorption centers, time, behavioral camps and space area and the allowable density of space. Creating flexible spaces with multiple functionality, maintaining scale and at the same time dynamism in normal days and hierarchical revival of endowment passages in the historical context of Najaf, are among the solutions that while calculating spaces based on modeling, the possibility of proper and gradual distribution of population Provide.

In recent decades, rising urbanization along with rapid growth of personal car ownership has made transportation as a major problem for policymakers in metropolitan areas. Thus, recognizing affecting factors on mod choice by traveler, especially at peak hours, has a special role in transport planning and travel management.
 The purpose of this article is determination of factors that affect mod choice behavior of educational-work travel in the peak hours of morning in Isfahan city using the nest logit model.
The results of estimating the mode choice bay this model show that demand for bus just depends on freight and time, and other factors do not affect the choice of bus for travel at that time. But the low price elasticity indicates that people are forced to use the bus as a vehicle. However, the demand for taxis in addition to time and freight depends on factors such as income, vehicle's comfort, head of the household and education but the price elasticity of this mod suggests that policymaker can encourage people for using taxi by reduction of freight and paying subside on using taxi.
The most important factor that influence the choice of a personal car is the comfort of the vehicle and being the head of the household. On other hand, demand for car is inelastic and policy maker have not Possibility to change people's demand by increasing price so, pricing policy can only make income for policy maker.

The pumping phenomenon is one of the major causes of damage in concrete pavements of roads and airports. To reduce the effects of pumping, this paper proposes attaching to the pavement slab a structural element of the same material that is oriented perpendicular to the pavement plane. The study investigated the effect of this structural element on the vertical deformation of the concrete pavement, especially around the edge of the slab, and the horizontal displacement of the fine fraction of saturated soil (base or bed) beneath the slab near the joints. Stress and deformation analyses were performed by modeling the slab-soil system under static and dynamic traffic loads in ABAQUS software. Stress and deformation analyses of the slab with and without the attachment (the element placed perpendicular to the slab plane) showed the positive effect of the element on the vertical deformation of the slab and also the deformation of the soil underneath the slab parallel and perpendicular to the direction of traffic. The edge displacement in the simple slab and the one with the attachment was determined to be 1.5 and 0.98, respectively. The highest vertical displacements in the modeled concrete slabs were observed in the simple slab under static loading (0.42) followed by the modified slab under static loading (0.3). The software outputs also showed the positive effect of the element on the stress in the concrete pavement slab and the soil beneath it.

The air fleet is considered as one of the most strategic transportation systems of any country. The high level and technological complexity, quality and strict prerequisite standards have made this system known as the most advanced transportation system in the world. In our country, the support of the air fleet has faced serious problems due to the intensification of oppressive sanctions by the West and the United States in recent years, which can be revived only by designing smart solutions to be self-sufficient in meeting this need. Appeared. Developing operational and efficient policies and strategies in this area can improve the current and unstable situation of the country's air fleet and revive this strategic area of transportation. In this article, the researcher, while examining the strategic position of this fleet through matrices of internal and external factors, using the matrix approach of strengths, weaknesses, opportunities and threats to provide effective strategies in providing and supporting it, and is trying. To be able to identify the limitations in this industrial field and eliminate them by providing effective strategies.

Limited energy resources and environmental issues arising from its high consumption require methods to determine project vertical alignment that, while ensuring driver safety and comfort and reducing road construction costs, reduce vehicle fuel consumption. This study seeks to incorporate fuel and earthwork costs in the vertical alignment determination problem. Moreover, this study makes use of a linear mathematical programming model method to minimize the cost of earthworks instead of the conventional Bruckner method, to perform more accurately in calculating the actual costs of earthmoving. In this paper, a combinatorial optimization model is proposed to determine the vertical alignment of roads, in which the optimal levels at the points of longitudinal slope change are determined. This has been done in a way that the weighted sum of construction cost and fuel cost are minimized. To solve the problem, a bi-level framework is proposed based on the Simulated Annealing algorithm, so that at the upper level, the optimal levels at longitudinal slope change points are determined based on the lowest total construction cost and fuel cost, and at the lower level the construction cost is minimized through a linear mathematical programming model. Results show that the speed and accuracy of the proposed algorithm is very appropriate compared to the brute force method and can be used in real-world projects.

Metro is known as one of the most important solutions to the problem of traffic and air pollution in the world. High safety, comfort and convenience of passengers, reduction of energy consumption, reasonable speed, low cost of passenger transportation compared to private cars are among the advantages of city trains over other public transport. Tehran Metro is called the Tehran city train complex and also the "Tehran and Suburbs Urban Railway Company". The metro operates on seven main lines. The purpose of train scheduling is to minimize train travel time from origin to destination, to satisfy passengers and stakeholders, to reduce delays at stations, and to maximize the capacity of lines, stations, and fleets. In this research, the case study is the urban train between Tehran and Karaj. In this study, variables such as train stop time, passenger volume at different hours, customer entry pattern and passenger waiting time have been considered as effective parameters in determining the train time distance. Existing uncertainties, scenarios were developed. The proposed goal is between 6-30 minutes in different scenarios for different hours to ultimately satisfy the citizens, save their time and finally help the urban management system to take steps towards sustainable urban development.

Today, ground transportation systems are facing a major challenge which has come to be known as traffic congestion. Since traffic and congestion are complex and dynamic phenomena, it is difficult and sometimes impossible to apply conventional mathematical models on them. Thus agent-based technologies with high compatibility with the afore-mentioned characteristics can be used to model the phenomenon of congestion and detect effective congestion mitigation/aggravation parameters. Considering the role of bus rapid transit in the transportation of passengers, mitigation of congestion and reduction of passenger waiting time and travel time are among the objectives of the present study. Therefore, agent-based simulation of the movement of bus rapid transit (BRT) fleets is used to achieve the afore-mentioned goal. In the present study, NetLogo is used to code the model and run the simulation. Three different scenarios were taken into account in this study. Change of effective factors in each of the three scenarios led to significant improvements in the BRT performance analysis results. Finally, after general analysis and comparison of different scenarios, results and suggestions were presented to improve the performance of BRT fleets. In the attempt to achieve the goals (i.e. reduction of passenger waiting time at stations and reduction of travel time), the bridge scenario was found to be more suitable and effective than the smart light and status quo scenarios.