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Airspace and air traffic management
Published in Lucy Budd, Stephen Ison, Air Transport Management, 2020
Controlled airspace can further be categorised as being a control zone, a control area, a terminal control area or an airway depending on its location and the function it performs: Control zones (CTZs) are located around certain aerodromes, and ATC is provided to all flights. CTZs extend upwards from the ground surface to a specific upper limit which varies according to location.A control area (CTA) is usually located above a control zone between defined flight levels.
Multi-lane-merging strategy for connected automated vehicles on freeway ramps
Published in Transportmetrica B: Transport Dynamics, 2023
Xiaoling Luo, Xiaofeng Li, Mohammad Razaur Rahman Shaon, Yongxiang Zhang
As this study is focused on planning for a prolonged period, the AHNBS is used in the optimization process. Thus, the planning time is divided into short periods of . The optimal sequence and trajectories of vehicles for each time duration are optimized. To facilitate the optimization problem, some basic assumptions are used according to previous studies (Priemer and Friedrich 2009; Li, Wen, and Yao 2014; Meng et al. 2018): The length of the control zone (communication range) is defined as 300 meters.The arrival times of vehicles at the control zone can be predicted in the next short period by the central controller.The arrival speed at the control zone and the departure speed from the control zone are assumed to be the free-flow speed.Vehicles are not allowed to change lanes once they enter the control zone.The Vissim built-in driver behavior assumption is used in the simulation process when the Vissim built-in strategy is used.Only the vehicles in the lane that joins with the ramp are involved in the merging process between the ramp and mainline.