In this study, using a microsimulation model, queues of Fatih Sultan Mehmet (FSM) Bridge toll booths are analyzed. Generally two queues form in the study area. First one is in front of the booths and the second one is after the booths, due to the existing bottleneck between the booths and the Bridge. Queue/delay performance of the system is analyzed incorporating the queuing theory. According to demand and service time of each server, queue may occur before the booths and/or before the bottleneck. The propagation of the second queue may overlap the first one because of the bottleneck capacity and for sure the increasing demand. Four different scenarios are simulated in order to evaluate capacity of the toll collectors and the bottleneck section. Some traffic management strategies are applied to improve the quality of service by decreasing delays and increasing capacities. In each scenario, average delay time per vehicle, average travel time, occupancy and speed data are obtained with microsimulation software, Vissim. Finally, optimum number of toll collectors is determined by seeking to minimize delays and maximize bottleneck capacity

Signal timings at signalized intersections are frequently optimized by considering commonly used vehicle delay models. It is generally believed that reducing the average number of stops can also decrease the average vehicle delay. Therefore, the aim of this research is to address the question: “Can similar performance outcomes be achieved through the Minimization of Average Vehicle Delay (MAVD) and the Minimization of Average Number of Stops (MANS)?” The first phase of the study entails the creation of two distinct signal timing optimization models based on the Akcelik average vehicle delay and average number of stops models. Subsequently, scripts were developed in MATLAB to identify the optimal signal timings for both approaches utilizing the Differential Evolution Algorithm. In the third phase, 30 traffic scenarios were generated, each varying in overall traffic volumes at the intersection. Subsequently, the signal timings derived from the MAVD and MANS approaches were applied independently to these scenarios, and performance indicators (average vehicle delay and average number of stops) were compared. The results reveal that the utilization of MANS-based signal timings instead of MAVD may lead to an increase in average vehicle delays of up to 113.55%. Additionally, it is demonstrated that when MAVD-based signal timings are applied instead of MANS, the average number of stops can increase by up to 16.28%. Finally, it is concluded that as the overall traffic volume at the intersection increases, these growth rates tend to decrease.

With the motivation of figuring out the reliability of link and route traversal times, we decompose our research into two stages those summarize modeling of travel times as a link performance and the analysis on the distribution and reliability of reconstructed travel times. In a separate paper, we seek the performance of two models by adopting traffic flow theory based reconstruction approaches. An overall evaluation on freeway travel time reconstruction performance of both a macroscopic and a microscopic model are presented considering real data obtained within a case study conducted on a stretch of Istanbul freeway network. While the initial paper presents the simulation results on both day and flow direction basis, we further consider the results in the explicit analyses on distributions and reliabilities of model reconstructions in the present paper. In order to investigate the distributions of route traversal times by considering explicitly the day-to-day variations, we apply the fitness test of normal distribution to the overall reconstructions by 5 weekday data and then proceed with the standardization of reconstructions and derivation of day-to-day distributions. Statistics obtained as order moments of travel time random variable are considered in the indication of reliability.

In this article, a quadratic programming problem is considered to identify all link flows in an arterial network when there are unmeasured link flows. A graphical method is provided to determine the minimum number of measurements and sensor locations required to obtain a fully observable model. It is shown that this method is also valid for the augmented graph with turn ratio measurements. If the minimum measurements required are met, a fully determined network can be obtained. If there is not enough measurement, a bound on the magnitude of the resulting inaccuracy in terms of vehicle kilometers traveled (VKT) can be calculated by the proposed linear programming method. The model is that of a queueing network; the parameters describe network geometry, saturation flow rates, turning ratios, timing plan and link flows. Three case studies are conducted to validate this approach. The first two cases are to calculate all missing flows by using a few numbers of measurements and minimum number of measurements required, respectively. Upper and lower bounds in terms of VKT are also calculated for these cases. Third case is to obtain a fully determined network with the minimum number of flow measurements when turn ratio sensors are included. Real measurements are collected from a network in Mugla including 55 links and 16 intersections. Vissim simulator is used to analyze the accuracy of the link flow calculations obtained from the proposed method. The results show that the proposed programming method can calculate the missing flows with a high accuracy and short computation time.

This paper discusses service times based on vehicle class at barrier-operated toll booths. Service times were measured using four vehicle classifications: car (C), medium goods vehicle (MGV), trucks & bus (TB), and articulated truck (AT) with two payment options: electronic (ETC) and manual toll collection (MTC). Each toll booth has both payment systems and resulting in mixed toll booth utilization in terms of payment and vehicles. The collected data was utilized to estimate logistic regression, and non-parametric statistical tests were performed. Findings indicate, when vehicle size increases, so does service time for even ETC. Furthermore, logistic regression used to compute threshold service times shifting from ETC to MTC for C, MGV, TB, and AT, which were 5.92, 7.51, 10.00, and 12.80 s, respectively. The transition time for a vehicle switch from ETC to MTC based on the logistic curve is denoted by threshold service time. Below the threshold, ETC is more favorable option and affected by barrier and vehicle class. Overall, the results indicate that operators can benefit from more dynamic operational conditions facilitated by threshold service times, enabling adaptive and efficient toll booth operations. Additionally, these thresholds can serve as valuable measure of service quality for managing freeway exits.