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International Journal of Transportation Engineering
Number of Followers: 2

This is an Open Access Journal

Open Access journal
ISSN (Print) 2322-259X - ISSN (Online) 2538-3728
Published by Tarrahan Parseh Transportation Research Institute

[1 journal]

Bicycle Demand: A Gender Analysis for Tehran, Iran
- Abstract: International studies on bicycle demand have shown that females and males can have different transportation behavior due to their innate differences, as in social responsibility and access to facilities. Considering the almost equal and significant share of females in urban trips, and also the cultural aspects, this issue is of even more importance in Tehran, which lacks detailed focused research studies. This paper aims to model bicycle demand for Tehran stressing on gender difference impacts. Regarding the scope of the research, a questionnaire field survey was designed to gather the required data for modeling purposes. Using a random sample of Tehran citizens stratified by employment status, the field survey was conducted, in March 2013. Data collected include demographic, economic, environmental, and travel information. The survey included the question, “How much do you use bicycle for urban trips'” as the dependent variable. Choice answers include four alternatives: never, rarely, sometimes, and often. Based on the collected data, ordered logit models are calibrated separately for males and females to analyse gender impacts on bicycle demand. Results indicate that age, number of cars, number of bikes and access to public transportation have different impacts on the demand of females and males for bicycle trips. Also, some variables such as education level and access to bike houses are found to be significantly related to males cycling but not females. It was also concluded that better and more in-depth information about gender differences in using bicycle is gained by estimating separate models for females and males.
A Social Engineering Optimizer Algorithm for a Closed-Loop Supply Chain
System with Uncertain Demand
- Abstract: This paper presents a new model for a closed-loop supply chain problem under uncertainty. This model considers production, distribution, collection, recycling and disposal of items simultaneously. Because of the increased importance of the environmental factors, this model focuses on the revers flow of the supply chain and considers different types of technology for recycling centers. The model aims to minimize the establishment cost of centers, shipment cost, holding cost, collection cost and recycling cost. To face with uncertain parameters, a credibility-based possibilistic programming method is applied. Then, a social engineering optimizer algorithm is proposed to solve the problem efficiency. To validate the model and proposed algorithm, the results are compared with the results of GAMS. In addition, they prove the superiority of the proposed algorithm over a genetic algorithm to deal with problems and find better results in less running time. Finally, the behavior of the model is assessed by changing the values of parameters and the results are reported.
A Genetic Algorithm with Multiple Populations to Reduce Fuel Consumption
in Supply Chain
- Abstract: Reducing fuel consumption by transportation fleet in a supply chain, reduces transportation costs and consequently, the product final cost. Moreover, it reduces environmental pollution, and in some cases, it helps governments constitute less subsidies for fuels. In this paper, a supply chain scheduling is studied, with the two objective functions of minimizing the total fuel consumption, and the total order delivery time. After presenting the mathematical model of the problem, a genetic algorithm, named Social Genetic Algorithm (SGA) is proposed to solve it. The proposed algorithm helps decision makers determine the allocation of orders to the suppliers and vehicles and production and transportation scheduling to minimize total order delivery time and fuel consumption. In order for SGA performance evaluation, its results are compared with another genetic algorithm in the literature and optimal solution. Finally, a sensitivity analysis is performed on SGA. The results of comparisons also show the high performance of SGA. Moreover, by increasing the number of suppliers and vehicles and decreasing the number of orders, the value of the objective function is reduced.
Moderation Effect of Raveling on Bleeding failure of Flexible Pavements
- Abstract: This paper evaluates the moderation affect of raveling on bleeding failure of Flexible Pavements with the support of moderation models. Failures in Flexible pavements results due to its component layers which undergo distress due to innumerable causes. There are different types of failures in Flexible pavements like alligator cracking, corrugations, shoving, pot holes, rutting, raveling and bleeding. Determination of the type and extent of failure and its reason is necessary to facilitate correction in mix design, construction and maintenance for the road projects. A moderator is a qualitative or quantitative variable that affects the direction and/or strength of the relation between an independent or predictor variable and a dependent or criterion variable. Four road sections have been considered for data collection and model validation. Linear models have been developed to check the mediation and moderation affects of raveling on bleeding failure for both the roads and these models are validated on other two road sections. The study accentuates that there is no mediating affect of raveling on bleeding but it affects the bleeding moderately.
Application of Conventional Mathematical and Soft Computing Models for
Determining the Effects of Extended Aging on Rutting Properties of Asphalt
Mixtures
- Abstract: Pavement performance prediction is a mounting task due to the many varied influencing factors particularly aging which varies with time, weather, production, type of pavement and etc. This paper presents a conventional mathematical model named Superpave model, Artificial Neural Network (ANN), and Supporting Vector Machine (SVM) techniques to predict the effects of extended aging on asphalt mixture performance measured in terms of rutting properties determined from the dynamic creep test. The accuracy of each method was compared to select the most reliable technique that can be used to forecast the rutting behavior of asphalt mixtures subjected to different aging conditions. The results indicated that the Superpave model was only reliable at lower temperatures, while ANN and SVM techniques showed the capability of precise prediction under all conditions. The overall results showed that the ANN was the most promising technique that can be adopted to satisfactorily forecast the effects of aging on rutting properties of all mixtures. The developed model can be embraced by the pavement management sector for more precise estimation of the pavement life cycle subjected to different aging conditions which can be used to design efficient pavement maintenance and rehabilitation plans.
Role of built-environment, lifestyle, attitude and behavioral factors on
mode choice- case of grocery shopping in Tehran
- Abstract: Although previous studies show that attitudes (personal preference) play an essential role in mode choice, few studies investigate the effect of heterogeneity of these factors in mode choice of grocery shopping. This research investigates the role of socioeconomic, built-environment, lifestyle, attitude, and behavioral variables on taste variation of individuals in mode choice of grocery shopping trips. 398 individuals are surveyed in chain grocery stores of Tehran in May 2016 and factor analysis is used to identify latent variable such as safety, pedestrian-oriented, mode flexibility. Furthermore, a mixed logit (MXL) model is employed to test heterogeneity among individuals. Results of MXL model show that several socioeconomic, mode attributes and attitude variables have significant effects on mode choice for grocery shopping activities. Besides, male variable in bus mode and travel time in walking mode is heterogeneous variables among parameters with random normal distribution coefficient for grocery shopping destinations. Moreover, the results of the random coefficient analysis show that the existence of a shopping center in the CBD without parking spaces for bus mode and household car ownership (two or more) for walking mode are the primary sources of heterogeneity of grocery shopping trips. Findings suggest that considering policies like parking management, especially in CBD and development of public transit stations, based consistent with the development of pedestrian facilities, increase the likelihood of using transit. Also, policies like optimal grocery shopping malls sitting in all areas of the city increase the likelihood of using walking mode.
Automated Guided Vehicles - A Review on Applications, Problem Modeling and
Solutions
- Abstract: In the past few decades, many research pieces were devoted to Automated Guided Vehicles (AGVs), both in hardware and software technology. Nowadays, these are popular for the automatic handling of materials, goods, and containers. They provide more efficient and flexible solutions for manufacturing and transportation systems. This paper does a survey on Automated Guided Vehicles in the real world, in port automation for automatic container handling and manufacturing systems for flexible material handling systems. The results of this survey reveal several corollaries over usage, modeling of problems, and solutions. Moreover, it presents several challenges for future research. The first challenge is to perform a simulation model that can handle multiple layouts in both container terminals and manufacturing systems. The second challenge is to work on the new technology of AGVs, which involves Industry 4.0. The third challenge is concerned with some dynamic vehicle routing strategies based on a two-tiered simulation. The fourth challenge is to develop more efficient algorithms for various problems of routing AGVs in practical applications.
Taste variation of the elderly mode choice
- Abstract: This research investigates the role of socio-economic and attitude factors on taste variation of the elderly in mode choice, and its main sources. Based on a total of 524 questionnaires distributed among the elderly in thirteen districts of Mashhad, factor analysis is used to identifying attitude factors like environmental, safety, convenience, comfort, and flexibility. Mixed logit and latent class models are employed to test heterogeneity among the elderly and also to determine its possible sources. Results of MXL show that several socio-economic, travel mode attributes and attitude factors have a significant effect on the elderly mode choice, which car ownership of the elderly and travel time of walking are heterogeneous variables among parameters with random normal distribution coefficient. Moreover, the results of latent class models show that flexibility is the main source of heterogeneity based on which individuals will fall into two classes. Results show that increasing the importance of the individual's attitude toward flexibility of travel mode, reduces the probability of individual's membership in class 1. Significant variables in class 1 include: having no accompanied, having a driving license, car ownership, flexibility, the travel time of walking and comfort. Findings suggest that identifying needs of the elderly and reducing travel time for non-mandatory trips encourage them to use public and walking mode. Also, incentive policies to reduce car ownership of the elderly and increase safety and comfort in other travel modes are essential factors in reducing the use of a private car for this age group.
Optimization of Delay Time at Signalized Intersections using Direction
-Wise Dynamic PCE Value
- Abstract: The study worked on direction-wise dynamic Passenger Car Equivalent (PCE) model to optimize delay at signalized intersection under heterogeneous traffic condition. Static PCE values are usually practiced to transform heterogeneous traffic into homogeneous stream. However, the PCE values are dynamic due to variation in vehicle composition. Video sensors were used to count direction-wise classified vehicle at various signalized intersections for this research. The adaptive PCE values were compared with the PCE values used in the manual of Roads and Highway Department (RHD), Bangladesh. Furthermore, Synchronous regression method was performed to estimate saturation flow. Field total delay was estimated from queuing diagram considering residual queue, arrival and saturation flow rate. After that, signal timing was adjusted by optimization of total delay. RHD manual based PCE was observed to be underestimated comparing to direction-wise dynamic PCE in case of field delay and optimized delay by 6.79% and 27% respectively. Turning vehicles occupy more space and time and influence operation of signalized intersection. Hence, conventional PCE estimation failed to comply with actual scenario, and consequently, could optimize signal timing inaccurately. This study can be used as a framework to calibrate practiced PCE values in the road capacity manual and design traffic signal.
Evaluation of the effect of driving education and training programs on
modification of driver's dangerous behaviors
- Abstract: In Iran, despite all efforts have been devoted to reduce crash frequencies, statistics indicate that the crash fatalities have recently been increasing. In more than 90% of accidents, human errors and misjudgements have been reported to be the main contributing factor. This has drawn significant attention to problems relating to driving style, which are generally formed by early-stage driver's education and training programs (DETPs). In this regard, in Iran, like any other jurisdiction, beginner drivers must participate in a short-term DETP before taking the driving license exam. The programs consist of two parts: classroom theory education and in-car practical training. This paper seeks to evaluate the effect of DETP on dangerous driving behaviours of drivers using Structural Equation Modelling (SEM). Accordingly, data relating to 510 drivers were gathered, regarding their demographics and attitudes about DETPs specifications. Results indicated that training can be more effective than education in reducing unsafe behaviours. In addition, human characteristics have been identified as an important factor in decreasing risky driving and this can easily fade the impact of a proper DETP. The related administrates also must consider more seriousness for the final exams and assessments of DETPs. Finally, the establishment of strict rules and punishments for traffic violations can be a successful way of increasing the efficiency of DEPTs.
Aggressive Driving: Self-Reported Anger Expression and its Relationship
with Driver Personality
- Abstract: Aggressive driving is a global road safety concern. However, little research has been conducted to understand the frequency of aggression nor what factors contribute to this. Moreover, in these researches, the effect of personality aspects on various driving anger expressions has not been investigated. The current study aims to investigate how drivers express their anger aggressively and its relationship with The Big Five personality traits. A total of 534 licensed drivers; 36.1 % had been involved in at least one crash in the last three years completed a brief survey assessing aggression and personality. Specifically, the driving anger expression inventory, which measures the frequency of verbal aggression, personal physical aggression, aggressive use of the vehicle and adaptive constructive responses, was investigated. The most common type of aggression was verbal aggression. Younger, and male drivers reported more frequent aggression. Neuroticism was related to all types of aggression, showing individuals with more neurotic characteristics also have more frequent verbal, personal physical aggression, use the vehicle more often to express anger and have less frequent adaptive constructive ways of dealing with anger. Neuroticism was also related to more crash involvement. In contrast, drivers with higher levels of conscientiousness more frequently dealt with anger in a constructive way and had been involved in fewer crashes. These findings show that the behavior and performance of drivers can be related to their personality and individuals higher in neuroticism report more dangerous behavior. This is important to assist with strategies to reduce high-risk driving in individuals.
Evaluation of performance characteristics of asphalt mixture reinforced
with palm tree fibers
- Abstract: Despite the high cost of paving the roads in Iran, according to experts, the useful life of asphalt is expected to be only 3 to 5 years. Thanks to the abundance of palm trees, the objective of this study is to determine the resistance of palm fiber-reinforced asphalt mixtures as an additive and asphalt modifier. In this study, four types of mixtures were prepared. The first mix was prepared as a control and non-fibrous mixture, and the second type were mixed with 0.1% and the third type with 0.3% and the fourth type with 0.5% weight of asphalt mixture of palm fiber. Six samples were prepared for each mixture, three samples were dried and three others were tested after partial saturation and moisture treatment with a melting and freezing cycle (24 samples). The Semi-Circular Bend Test (SCB), Marshall Stability of bituminous mixture, flow tests, indirect tensile strength, resilient modulus and moisture damage were assessed. The results of indirect tensile strength test showed that the use of palm fiber in dry condition at all percentages of 0.3, 0.4 and 0.5% improves the resistance. In saturated state, for fibers added up to 0.3% results were positive, but for more fibers, the results were negative. For moisture sensitivity parameter of the asphalt mixtures of the addition of fiber up to 0.3%, the least moisture damage was observed. The results of the resilient modulus of the mixtures showed that using 0.3% fiber had better result than other percentages and control sample.
Effects of Combined Environmental Factors on Stiffness and Rutting
Properties of Warm Mix Asphalt
- Abstract: Warm mix asphalt (WMA) is a sustainable clean product that can be fabricated at lower temperatures. This is an environmentally friendly mixture due to its lower emission and energy consumption in asphalt production plants. Moisture conditioning and aging process are two environmental factors that can adversely affect the stiffness properties of this product. In the field, WMAs are subjected to both moisture damage and aging. In this paper, a new laboratory method was used for evaluating the combined effects of aging and moisture conditioning of WMA samples. WMA specimens were fabricated at various compaction temperatures with different amounts of a surfactant-wax warm additive. Stiffness properties of asphalt mixtures were quantified from the resilient modulus and dynamic creep test. The results showed that moisture conditioning and aging are competing to affect the stiffness properties of mixtures. Polymer modified asphalt mixtures were found to be less susceptible to moisture damage when compared to mixtures fabricated with unmodified binder. Compaction temperature was the most significant factor that affected the resilient modulus of WMA. In the dynamic creep test, the combined effects of aging and moisture conditioning reduced the cumulative micro strain of samples regardless of binder type, additive content and compaction temperature.
Development of a new integrated surrogate safety measure for applying in
intelligent vehicle systems
- Abstract: This paper aims to develop a new Surrogate Safety Measure (SSM) for applying in In-vehicle collision avoidance warning systems. To send safety alarms, the amount of collision risk is required, which of course can be measured with only one measure. To accurately determine the risk of an accident at any given time, 7 valid safety measures including Time to collision (TTC), Modified TTC (MTTC), General formulation for TTC (GTTC), Deceleration-based surrogate safety measure (DSSM), Difference of Space distance and Stopping distance (DSS), Deceleration rate to avoid collision (DRAC), and Proportion of Stopping Distance (PSD) were used together and with different thresholds to provide a more accurate estimate of the risk for each moment. A certain range of thresholds was assigned to each of the mentioned measures. As a result, Adequate number of thresholds (in this paper 800 thresholds) were created for the 7 measures. One of the advantages of this system is that it not only considers the present time to provide an alarm, but also the recent past of the vehicle (the last half-second). This means that the proposed integrated measure can determine the risky situations by considering the past and present of the vehicle. Finally, given the estimated collision risk and also based on the ascending or descending trend of the risk according to the vehicle's past situation, five alarm types were designed. The greater the risk of a collision in a moment, the stronger and more efficient the alarm type