# Hub Airport End-Around Taxiway Construction Planning Development: A Review
## 2 Research Methodology and Literature Review
### Contribution of EAT-Reducing Runway Incursions and Enhancing Safety Margins  
The EAT was initially introduced to reduce runway crossings. The number of runway crossings is directly related to the number of runway operations [13; 14]. When the runway  
Figure 1: Flow chart of the study process. capacity is not yet saturated, landing aircraft can cross using the takeoff aircraft interval [15; 16; 17; 18]. With the increase in peak period operations, more runway crossings become inevitable [19; 20; 21; 22; 23]. Although the takeoff interval on the inner runway theoretically meets the crossing time, the inherent safety risks associated with crossing itself require the air traffic control, crossing pilots, and waiting pilots to concentrate at the same time to ensure a successful crossing [19; 20; 21]. The interactions between aircraft and equipment, controllers, and ground vehicles are complicated, which may lead to high levels of concentration and fatigue for pilots and controllers [24; 25; 26; 27; 28; 29; 30]. Verbal communication commands can also pose risks to communication safety, making human error unavoidable [26; 27; 28; 29; 31; 32]. In recent years, runway incursions caused by aircraft crossing the runway have occurred frequently. From January to April 2023, 550 runway incursions occurred at US airports [33]. Among them, in January, a B373 was taking off from New York Kennedy Airport while another B777 was crossing the runway. The controller stopped the takeoff in time to avoid accidents [33]. Similar incidents were reported in China as well. At Shanghai Honggiao Airport (SHA) in October 2016, a tower controller's negligence led to a near collision between a departing aircraft and an arriving aircraft that was crossing the runway. Later that year, at Shanghai Pudong Airport (PVG), the captain of an arriving flight crossed the runway without authorization from the controller, and just as another flight was preparing to take off, the tower immediately canceled the takeoff [34]. In November 2018, at PVG, a departing flight was on the takeoff runway, and the crew observed an aircraft intruding at the end of the runway and immediately aborted the takeoff [35]. EATs alleviate these issues by allowing pilots to bypass runways without instructions, reducing the workload for both controllers and pilots [36]. This indirectly decreases the possibility of runway incursions caused by human factors [27; 28; 29]. Evaluation at Dallas-Fort Worth International Airport (DFW) by Dr. [PERSON] and his team showed that EATs reduced runway incursions caused by pilot deviation by 40% at around 50% usage rate [4; 37]. Traditionally, EATs were believed to be primarily used during peak hours, while aircraft relied on crossing runways during non-peak hours. However, research shows that this is not necessarily the case. Researchers conducted six months of data collection using ASDE-X data at Hartsfield-Jackson Atlanta International Airport (ATL). During a typical day in a peak month, EAT was used for most of the day from 9:00 to 23:00, indicating its effectiveness beyond just peak hours. EAT was utilized sufficiently throughout most of the day, and controllers chose to use it when they realized that crossing runways required more attention and decreased efficiency. Therefore, except for the high usage rate during peak hours at 11:00, 16:00, and 20:00, the usage of EAT was relatively balanced between 8:00 and 24:00 [38]. This study illustrates implementing EATs is not only a solution for peak-hour congestion but also an effective choice throughout the day. Controllers' awareness of their benefits contributed to their widespread utilization, reducing the workload on pilots and controllers and improving communication safety. Furthermore, a study was conducted on the average usage rates of EATs at DFW, ATL, and Detroit Metropolitan Airport (DTW).