Tarrahan Parseh Transportation Research InstituteInternational Journal of Transportation Engineering2322-259X1120130101Behavior of Flexible Pavements on Expansive Soils116262610.22119/ijte.2013.2626ENAdelDjellaliAssistant Professor, Department of Civil Engineering and Hydraulics, University of Mohamed Khider, Biskra, AlgeriaAbdelhafidOunisAssistant Professor, Department of Civil Engineering and Hydraulic, University of Mohamed Khider, Biskra AlgeriaBehroozSaghafiAssistant Professor, Tarahan Parseh Transportation Research Institute, Tehran, IranJournal Article20120822This investigation discusses the findings on analysis results of a pavement structure constructed on a relatively expansive material consisting mainly of brown clayey silt in Tebessa, Algeria. Cores were brought to the laboratory from a piece of roadwork. Remolded samples were taken from subgrade of a deteriorated road. The soils were generally found to be of medium plasticity and of a medium to high expansion potential. Oedometer test for free swell indicated a constant volume pressure that produced stress in excess of 350 kN/m2. The following involves describing the behavioral characteristics of expansive soil as it relates to flexible pavements. Soils are generally classified using the X-ray diffraction [XRD]. Computer code Plaxis 8.2 was used for numerical simulation to check the behavior of structure pavement with three models in pavement structure, and free expansion test was performed to calibrate the soil subgrade with Soft-Soil model. The study is based upon simulating the vertical subgrade soil displacement during traffic load, and its influence on load-settlement on flexible pavement behavior. To stabilize the swelling character of subgrade, an adequate surcharge pressure is used according to the procedure described in the article.http://www.ijte.ir/article_2626_e354fd90b2d5c777bfec87a352a18976.pdfTarrahan Parseh Transportation Research InstituteInternational Journal of Transportation Engineering2322-259X1120130101Application of Chaos Theory in Hazardous Material Transportation1724262710.22119/ijte.2013.2627ENAbbasMahmoudabadiPh.D. Candidate, Department of Industrial Engineering, Payam-e-Noor University, Tehran, IranSeyed MohammadSeyed HosseiniProfessor, Department of Industrial Engineering, Iranian University of Science and Technology, Tehran, IranJournal Article20120403Risk factors are generally defined and assigned to road networks, as constant measures in hazmat routing problems. In fact, they may be dynamic variables depending on traffic volume, weather and road condition, and drivers' behavior. In this research work, risk factors are defined as dynamic variables using the concept of chaos theory. The largest Lyapunov exponent is utilized to determine the presence of chaos for road accident rates. Risk factors with the property of chaotic behavior are considered to solve hazmat routing problem using a developed mathematical model. Evaluation process has been done based on travel distance which mainly represents travel cost, as well as results that show the application of chaos to define dynamic risk factor appropriate method to solve hazmat routing problem, comparing to constant measures of risks.http://www.ijte.ir/article_2627_4de81d9105c85bca6e6e4666e6dd536a.pdfTarrahan Parseh Transportation Research InstituteInternational Journal of Transportation Engineering2322-259X1120130101A Model for Predicting Schoolchildren Accidents in the Vicinity of Rural Roads based on Geometric Design and Traffic Conditions2533262810.22119/ijte.2013.2628ENBabakMirbahaPh.D student, Department of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, IranMahmoudSaffarzadehProfessor, Department of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran0000-0002-9713-2776Mohammad HosseinNoruzoliaeeMSc graduate, Department of Civil and Environmental Engineering, Tarbiat Modares University,
Tehran, IranJournal Article20120929awareness they gain from their surroundings. Recent statistics indicate that about 40 percent of road accident fatalities are pedestrians, 30 percent of which are under 18 years old. Based on the fact that almost two million Iranian students study in the vicinity of rural roads, this paper aims to develop a model for predicting the risk of students’ accidents near the aforementioned schools. Therefore, by gathering data from schools located in rural areas, schools are divided in three categories which are: no risk (no accidents/year), medium risk (one accident/year), and high risk (two or more accidents/year). A multinomial logit (MNL) model has been chosen and the utility function was considered as a combination of variables such as road width, functional speed, presence of school guardian, number of students and the ratio of average daily traffic to the distance of schools from roads. Results indicate that the proposed model can predict the risk of accident occurrence with the accuracy of more than 70 percent. Meanwhile, school guardian is known as an important variable in the prediction model. Also, results show the important role of the road width and proposed ADT/Dis variables.http://www.ijte.ir/article_2628_8e065119c74efe3a47aec8796964cf8b.pdfTarrahan Parseh Transportation Research InstituteInternational Journal of Transportation Engineering2322-259X1120130101Modeling Multiple–Vehicle Property Damage Collisions in Urban Signalized Intersections3546262910.22119/ijte.2013.2629ENSeyed SaberNaseralaviAssistant Professor, Department of Civil Engineering, Shahid Bahonar University of Kerman, Kerman, IranMasoudGhasemi NoughabiMSc. Department of Civil Engineering, Shahid Bahonar University of Kerman, Kerman, IranEsmaeelAyatiProfessor, Department of Civil Engineering , Ferdowsi University of Mashhad, Mashad, IranJournal Article20120823Development of disaggregate models for estimating different property damage collision type frequencies in urban intersections has rarely been studied, particularly in Iran. It seems very little research work being implemented for studying the effect factors on collision type frequency at intersections. The main objective of this paper is to develop suitable statistical models to predict types of property damage accident frequencies at signalized intersections approaches in the Mashhad of Iran based on geometric, traffic, and regulatory control characteristics. Three negative binomial models are estimated for collisions occurred in four-leg signalized intersections in the city of Mashhad and their results were compared together. These models are total, rear-end and right angel collision models. The goodness of fit was assessed by statistic tests. The Incidence Rate Ratio is used to assess the effectiveness of independent variables on frequency of property damage collision. Validation of models was controlled using paired samples T-test method. Modeling collision types showed a strong relationship between frequency of property damage collision types and independent variables such as road geometry, the type of control system and traffic characteristics. The results of this study revealed that seven of independent variables considerably affect the safety of signalized intersections.http://www.ijte.ir/article_2629_8cff9bf6694dccfc3b6a613d05d51d16.pdfTarrahan Parseh Transportation Research InstituteInternational Journal of Transportation Engineering2322-259X1120130101Different Network Performance Measures in a Multi-Objective Traffic Assignment Problem4758263010.22119/ijte.2013.2630ENAmir AbbasRassafiAssistant Professor, Department of Civil Engineering, Imam Khomeini International University, Qazvin, Iran.DavoodJamourM.Sc. Grad., Department of Civil Engineering, Imam Khomeini International University, Qazvin, Iran.HamidMirzahosseinPh.D. Candidate, Department of Civil Engineering, Iran University of Science and Technology, Tehran, Iran.Journal Article20120620Traffic assignment algorithms are used to determine possible use of paths between origin-destination pairs and predict traffic flow in network links. One of the main deficiencies of ordinary traffic assignment methods is that in most of them one measure (mostly travel time) is usually included in objective function and other effective performance measures in traffic assignment are not considered. The current study is an endeavor to introduce a solution for this problem by applying a multi-objective optimization idea to traffic assignment models. To do this, first, a problem with three objective functions including travel time, total distance traveled, and the rates of cabin monoxide emissions is studied, and then problem with two objectives combining two well-known assignment approaches i.e. user equilibrium and system optimal is introduced. Using the weighting method to solve the multi-objective problem, and comparing the results, show that the analytical relationships resulted from weighting method is applicable to different networks. Furthermore, comparison of both multi-objective problems and single-objective one (travel time only) showed that the results of proposed model is more appropriate in terms of having a plenary view to this issue, and thus more useful.http://www.ijte.ir/article_2630_dd17e652cd2a08fdb8bf7f68e2ad3814.pdfTarrahan Parseh Transportation Research InstituteInternational Journal of Transportation Engineering2322-259X1120130101Asphalt Pavement Performance Model of Airport Using Microwave Remote Sensing Satellite5968263110.22119/ijte.2013.2631ENWeerakasetSuanpagaDepartment of Civil Engineering, Faculty of Engineering, Kasetsart University, Bangkok, ThailandJournal Article20120618The purpose of this study is to build the binary logit model of an airport pavement that could monitor the pavement condition in near real time using microwave remote sensing satellite, then the relationship between the international roughness index (IRI) of an airport and backscattering values from PALSAR images of the ALOS satellite was determined. Total 390 data were used in analysis. This model could be applied to evaluate the efficiency of the quality of running service on the airport pavement. The analysis showed that the backscattering values in the HH and HV polarization have correlated with IRI, and HH polarization was the highest correlation with IRI value (r = 0.90). If the backscattering value in HH polarization was increased, the roughness will be increased. After the validation process on other 100 data, the result presented high correlation at 94.00%. Therefore, these can be concluded that this model could be applied to the airport pavement maintenance.http://www.ijte.ir/article_2631_e113bb92c69391dd39e2488f9f588382.pdf