Transit Network Design Problem is a multi-disciplinary problem that is considered one of the most intractable problems for real size networks. In the late 90s, Meta-heuristics started to prove more reliability to the problem. Genetic Algorithm (GA) is one of the popular Meta-heuristics which is usually implemented because it is simply adapted to the problem. In this study, GA is presented as a complete constructive multi-objective algorithm that creates its own routes from scratch then assembles the routes into efficient transit networks. Finally, it handles the multi-criteria nature of the problem until producing the optimal (near optimal) Pareto front solutions. A new frequency setting algorithm is also developed based on simulation results at the bus stop level which takes the bi-level decision making of both users and operators implicitly. Experimental studies on two real size networks are conducted to validate the methodology performance and robustness.

Air contamination becomes an urgent problem to be considered as a result of the rapid growth in traffic all over the world. Traffic emissions differ from vehicle to vehicle depending on the vehicle type, production year, fuel octane number, and periodical maintenance of the vehicle. The majority of drivers do not revise their harmful vehicles emissions regularly. Therefore, effective tracking of high-emitting vehicles can be an important solution for reducing traffic air pollution. This study proposes a location strategy for vehicle remote sensing monitors aided with ID-plate recognizer to capture any violated vehicle emissions. The problem is formulated into a graph theory problem, and then a novel adapted metaheuristic algorithm is used to solve the problem. The methodology, using a benchmark problem, has managed to solve the problem to the optimality. Moreover, its robustness is measured statistically.

Routing problems play a crucial part in urban transportation network operation and management. This study addresses the problem of finding a set of non-dominated shortest paths in stochastic transportation networks. Instead of the previous practice of assuming the travel time variability to be tracked by a known probability density function, it is extracted from the existing correlation between the traffic flow and the corresponding links' time. The time horizon is divided into time intervals/slots in which the network is assumed to experience a static traffic equilibrium with different traffic conditions for each slot. Starting with Priori demand information, prior generated paths, and a chosen traffic assignment method, the proposed methodology conducts successive simulations to the network intervals. It manages to draw both links and paths probability distribution of their travel time considering the correlation among them. Then, multi-objective analysis is conducted on the generated paths to produce the Pareto-optimal set for each demand node pair in the network. Numerical studies are conducted to show the methodology efficiency and generality for any network. The expected travel time and the reliability could be drawn for each path in the network.

The available code provisions for seismic design of confinement reinforcement in fiber-reinforced polymer reinforced concrete (FRP-RC) columns, even their most recent versions, are overly conservative. This is due to the limited available research data, particularly those related to high-strength concrete (HSC) columns and those  with different aspect ratios. That is, the linear-elastic behavior of FRP could be of concern when combined with the brittle nature of HSC or implemented in shorter columns, which could be significantly influenced by shear stresses. Therefore, this study was conducted to investigate the effects of concrete compressive strength and column aspect ratio on the seismic performance of glass FRP (GFRP)-RC circular columns with variation of spiral pitch and axial load level. Nine full-scale GFRP-RC column-footing connections were cast and tested under concurrent axial loading and reversed-cyclic lateral drifts. Test results proved the conservativeness of the seismic design requirements of the Canadian standards for confinement reinforcement in GFRP-RC circular columns with regard to the effects of HSC and different aspect ratios.

The seismic behavior of fiber-reinforced polymer-reinforced concrete (FRP-RC) columns is far from being fully explored. Therefore, numerical and analytical studies were performed to address the effects of different parameters and evaluate the current design provisions for confinement reinforcement under seismic loading. Using a commercially available software package, a three-dimensional nonlinear finite element model (FEM) was constructed and validated against the experimental results of full-scale glass FRP (GFRP)-RC circular columns previously tested by the authors. The validated FEM was, then, used to conduct an extensive parametric study investigating the effect of concrete compressive strength, spiral pitch, axial load level, and column aspect ratio (i.e., shear span-to-depth ratio). It was found that increasing the concrete strength caused an increase in lateral load capacity and initial stiffness, whereas the drift capacity decreased. The latter property was also significantly affected by the variation of spiral pitch and axial load level. On the other hand, the aspect ratio had a marginal effect on moment or drift capacities. Using the results of the FEMs, two new design models were proposed. The proposed models showed remarkably better predictions than the equation adopted by the Canadian standard for the design of FRP-RC structures.

The available provisions for the seismic design of fiber-reinforced polymer (FRP)-reinforced concrete (RC) columns were fundamentally derived from design models created for steel-RC ones due to the limited research data on the former. This, in turn, may justify the conservativeness of such provisions, particularly those concerning the design of confinement reinforcement for columns with different aspect ratios. This study investigates the effect of the aspect ratio and axial load level on the seismic response of columns reinforced with glass FRP (GFRP) by testing six full-scale GFRP-RC circular columns under earthquake-simulated loading. The experimental results revealed that, unlike steel-RC columns, changing the aspect ratio insignificantly influenced the hysteretic response of GFRP-RC columns, indicating that the available code provisions for confinement reinforcement design are overly strict. Furthermore, recommendations are proposed for the seismic design of confinement reinforcement in GFRP-RC columns.

The linear elastic behavior of fiber-reinforced polymer (FRP) reinforcement makes it controversial to implement in seismic-resistant reinforced concrete (RC) structures. More concerns could be raised when such reinforcement is associated with high-strength concrete (HSC). Columns in multi-story buildings or bridges are common examples of structural members constructed using HSC. To date, all available research data on glass FRP (GFRP)-RC columns have shown that they have a maximum limit of concrete compressive strength equal to approximately 55 MPa (8000 psi). The results of five full-scale column-footing specimens are presented to study the seismic response of GFRP-RC columns, highlighting the effect of concrete compressive strength alongside other factors such as spiral pitch and axial load. It is concluded that when properly confined, GFRP-reinforced HSC circular columns can exhibit a stable seismic response with sufficient deformability. Moreover, several confinement and performance indexes were adjusted and evaluated to introduce an informative relationship for the design of
GFRP-RC columns.

Traffic flow data is a decisive element in transportation planning and traffic management. Over time, traffic sensors have been recognized as sources of such data. Despite their outstanding capabilities in measuring different traffic flow information types, they are not practical to apply across all transportation network streets or intersections. Thus, the traffic sensor location problem (TSLP) has emerged to answer two typical questions: how many sensors are needed, and what are the best locations for their deployment. This paper reviews the TSLP classes that have been extensively examined in the literature over the last three decades. This study tries to fulfill two major gaps in the existing literature. First, this is the only review article that summarizes the contributions made toward solving the TSLP spanning nearly 30 years. Second, it presents a comprehensive review and analysis of most TSLP studies with a new categorization system. This contribution clarifies the progress made and provides recommendations for further research.

Due to the poor cracking performance of aged binders, the use of reclaimed asphalt pavement (RAP) in road pavements is limited. When applying a greater RAP percentage, the use of a rejuvenator is necessary. The rejuvenator’s unfavourable softening impact, on the other hand, causes the pavement to be vulnerable to rutting. As a result, RAP binders with optimized rutting and fatigue cracking properties are required. Therefore, this study was carried out to evaluate the simultaneous effects of 70% waste engine oil (WEO) and 30% SBS copolymer as a compound rejuvenator (WS-rejuvenator) on the performance of asphalt binders and mixtures containing RAP binders of 30% and 50%. The physical, chemical and rheological properties of asphalt binders were evaluated using the conventional tests, SARA (Saturate, Aromatic, Resin, and Asphaltene) analysis, FTIR test, thermal gravimetric analysis (TGA), DSR, and BBR. The mechanical properties of mixtures were examined using the Marshall, indirect tensile strength, moisture damage, rutting, and aggregate coating tests. The findings showed that WS-rejuvenator at 5% and 10% recovered the physical characteristics of asphalt binders containing 30% and 50% RAP, respectively. Furthermore, WS-rejuvenator was able to compensate for the light components of the RAP binder that were lost over time. As a consequence, the behavior of the RAP binder at high, moderate, and low temperatures was recovered to that of the virgin binder. By mixing the RAP binder with the compound rejuvenator, the oxygenation indices were effectively reduced. The TGA revealed that the thermal stability of regenerated binders was equivalent to that of the virgin binders. In addition, the mechanical properties of regenerated mixes were enhanced in comparison to the control mixture. In summary, the adoption of RAP and WEO-SBS rejuvenator in asphalt mixtures show promising outcomes to enhance greener pavement materials application in the future.

Transit network design problem (TNDP) usually needs a recursive solution to successive transit assignment problems. Interestingly, the transit assignment problem is complicated with several unique criteria. In this study, we comprehensively review two well-known graphical transit assignment models from the literature. The first model is based on the hypergraph theory by Spiess and Florian (1989), and the second is the section transit network representation of De Cea and Fernandez (1993). The two assignment approaches are formulated in a single mathematical notation framework for the first time in the literature to understand the inherent differences better. We aim to bring attention again to these approaches for the upcoming TNDP studies since the most used transit assignment models in the TNDP are deficient in their basic assumptions compared with the considered models.