International Journal of Transportation Engineering
Volume:12 Issue: 3, Winter 2025

For several decades, finding the optimal location of counting sensors in a traffic network to obtain the best estimates of the O-D matrix has attracted a growing amount of attention. The availability and the accuracy of a priori data in a network such as O-D matrix and route choice probabilities on one hand, and the complexity of the mathematical operations for solving the location problem even in not a large network, on the other hand, are two main concerns of the presented methods. This paper aims to propose a method that identifies optimum locations for counting sensors without utilizing any a priori data. Relying on the network topological characteristics and link travel times as the representation of the network’s pattern of trips is the core concept of this study. By taking benefit of the frame theory algebraic operations, needless of any pre-given a priori data, the location set vector with higher coverage on the network route vectors is identified as the optimal location set of the sensor-equipped network links based on its representation in the route-vectors frame. The most probable used paths are identified utilizing an efficient path algorithm. Additionally, by taking advantage of the matrix operations, the novel method obviates the calculations required in methods using linear or non-linear programming solutions. The presented method is applied on a test network and the results show that in comparison to the non-linear programming method, the proposed method finds a better solution.

Mounting environmental challenges and diminishing mineral and energy resources have led researchers to concentrate more on improving cold asphalt technologies. Despite its advantages, the cold asphalt mixtures’ poor performance against permanent deformations and fatigue is the main reason they are not preferred in road construction projects in contrast to the typical hot asphalt mixtures. The effects of adding fibers with fatty-arbocel to a cold asphalt mixture were evaluated to overcome this weakness. Marshall Tests, static creep tests, and wheel track tests were applied to evaluate rutting and fatigue. The results showed that including cement and fibers with fatty-arbocel in a cold emulsion asphalt increases the mixture’s stiffness, improves the load-bearing strength and modulus of elasticity, and enhances the load transfer. The results showed the best performance in samples containing 3% cement and 0.3% above fib ers. The results of physical and functional tests showed that combining cement and fatty fibers with arboreal can significantly reduce maintenance costs.

Nanoparticles can play a significant role in enhancing the properties and performance of concrete used in roadway construction. Nanoparticles can help improve the durability of concrete by reducing permeability and enhancing resistance to various deleterious processes, such as freeze-thaw cycles, chemical attack from road salts, and alkali-silica reaction. This research explores the potential of magnesium oxide nanoparticles as partial substitutes for cement to serve as dense barriers against liquid penetration into concrete. Unidirectional compression and splitting tensile tests were conducted to evaluate the compressive and tensile strengths of concrete specimens incorporating 0%, 0.1%, 0.5%, 1.0%, and 1.5% magnesium oxide nanoparticles at ages of 7 and 28 days. Additionally, the permeability and water absorption rate of the concrete were assessed. Scanning electron microscopy images are utilized to visually demonstrate the uniform dispersion of nanoparticles within the cement paste. Findings reveal that even a small quantity of nanoparticles leads to a significant enhancement in the mechanical properties of concrete and a reduction in water permeability. Additionally, behavioural models employing genetic algorithm programming are developed to characterize the time-dependent properties of nanoparticle-blended concrete specimens under varying compressive and tensile stress conditions at different ages.

Today, the use of asphalt pavements in the world shows an ascending trend. Since rutting failure is among the most common failures on roads, laboratory information is required to evaluate the potential of rutting. The static creep test has been used to evaluate the rutting susceptibility of asphalt mixtures for a long time. Evaluating the strains created in asphalt mixtures at different loading times and temperatures is among the most essential methods for modeling the visco-elastic behavior of asphalt mixtures. In addition, mechanical models have been used to evaluate the nonlinear viscoelastic behavior of asphalt mixtures. Some of these models include Burgers, Maxwell, generalized, and Kelvin models. In this research, the creep behavior of asphalt mixtures is evaluated over time using static creep tests at 2, 3, 4, and 5 bar at the controlled temperature of 40℃. Next, coefficients of determination (R2) for different mechanical models are determined to evaluate viscoelastic behavior. The experimental results and proposed mechanical models indicate that the Burgers model has the best performance (R2 = 0.8) in predicting the viscoelastic behavior of asphalt mixtures at different pressures with a reliability of 95%. Finally, a logarithmic nonlinear viscoelastic model was proposed to predict the creep of asphalt mixtures by matching the experimental data.

Speeding is one of the most leading causes of almost any road traffic crash; that can increase either crash frequency or intensity. As a well-known intelligent transportation system (ITS), automated section control average speed cameras can enhance the traffic safety through spot control and section control. Previous studies looked at how much crashes might be related to speed, but they didn't look into how cameras could change crash patterns. In this regard, the present paper aims to investigate section control speed cameras' safety effects on Qazvin-Karaj freeway crash variables., eight years of police-reported crash data (2011–2018) were analyzed using the Chi-square (χ2) test of independence. The results indicated that regardless of crash variable type, there is a statistically significant relationship between the crash frequency variations and speed camera installation. However, Cramér's V measure degree of association showed an ignorable correlation between section control speed camera installation and crash intensity and crash time variations. However, this index depicted more significant but still marginal impacts of their installation on crash category and crash type, with Cramér's V values of 0.208 and 0.188, respectively. Applied research has cleared the effects of speed cameras on crash-related variables that can assist stakeholders in the decision-making process that help them toward prioritizing budget assignment to make road safer in view of speed management.

Bus as a means of transport plays a crucial role in Dhaka city. For being the cheapest means of transport, people rely heavily on bus service. Although people use the available bus service, they are not satisfied with the provided service. Considering the present and future condition of bus service, it is very important to assess the existing bus service and improve its service quality (SQ). This study aims to investigate key service factors influencing the bus SQ in Dhaka city by choice model. For this study, two step methodologies were followed where the first step was to collect data by questionnaire survey and the second step was to develop the model. An interview survey was done at 15 major locations of Dhaka city. The questionnaire had a total 40 service attributes, divided into 7 main parts including ‘trip characteristics’, ‘quality of service’, ‘quality of bus’, ‘quality of bus stop’, ‘safety and security of bus’, ‘staff behavior’ and ‘reliability and accessibility of bus’. In the second step, Ordered Probit Model (OPM) was developed. Result indicates that ‘Seat comfort level’, ‘Physical condition of bus’ and ‘Paying fare/Ticketing system’ was the most important and key service attributes influencing bus SQ. The result from the study will be convenient to the bus service providers as it will let them know the improvement opportunities for enhancing bus SQ. Furthermore, findings from this research can be employed to develop rules and regulations to improve bus SQ in developing cities.