This paper evaluates the traffic safety of freeway interchange merging areas based on the traffic conflict technique. The hourly composite risk indexes (HCRI) was defined. By the use of unmanned aerial vehicle (UAV) photography and video processing techniques, the conflict type and severity was judged. Time to collision (TTC) was determined with the traffic conflict evaluation index. Then, the ...

Performance of an automated conflict resolution algorithm is assessed. Evaluations are based on fast-time simulations of 24 hours of nominal and heavily increased air traffic demand in the Cleveland Air Route Traffic Control Center airspace. Departure, en-route, and arrival traffic were represented, based on recorded Host data. The algorithm is designed to resolve detected conflicts—projected t...

We address the conflict detection and resolution problem in air traffic control, where an aircraft conflict is a loss of separation between aircraft trajectories. Conflict avoidance is crucial to ensure flight safety and remains a challenging traffic control problem. We focus on speed control to separate aircraft and consider two approaches: (i) maximize the number of conflicts resolved and (ii...

Filmed traffic conflicts were evaluated in terms of their severity using an objective measure and two subjective measures obtained from two groups of subjects. Each observer rated the same conflicts three times. Correlations among the subjective measures and between the subjective measures and the objective measure were used to evaluate some aspects of the reliability and validity of the subjec...

Based on microscopic traffic characteristics of two-lane highway and different driving characteristics for drivers, the characteristics of drivers and vehicle structure are introduced into Cellular Automation model for establishing new Cellular Automation model of two-lane highway. Through computer simulation, the paper analyzes the effect of the promotion of different vehicles, drivers and arr...

We present an agent based model of the Air Traffic Management socio-technical complex system aiming at modeling the interactions between aircraft and air traffic controllers at a tactical level. The core of the model is given by the conflict detection and resolution module and by the directs module. Directs are flight shortcuts that are given by air controllers to speed up the passage of an air...

Optical communication networks and air traffic management systems share the same fundamental routing problem as both optical packets and aircraft must continuously move within the network, while avoiding conflicts. In this paper, we explore the use of hot potato and deflection routing algorithms, which are established routing methods in optical communication networks, in the conflict-free routi...

A metaheuristic approach based on Variable Neighborhood Search to tackle the enroute aircraft conflict resolution problem is presented. The three maneuvers (velocity, heading angle and altitude level variations) are allowed to be performed. Based on geometric rules, we can determine if a conflict situation occurs between each pair of aircraft under consideration. As three different maneuvers co...

The challenge to address in multi-firewall and security gateway environment is to implement conflict-free policies, necessary to avoid security inconsistency, and to optimize, at the same time, performances in term of average filtering time, in order to make firewalls stronger against DoS and DDoS attacks. Additionally the approach should be real time, based on the characteristics of network tr...