# Data-Driven Deployment of Cargo Drones: A U.S. Case Study Identifying Key Markets and Routes
## 2 Literature Review  
Though 'last-mile' is a frequently used term in transport logistics,'middle-mile', denoting cargo movement between intermediary facilities, is less prevalent [13]. Amazon cautions that inefficiencies in the middle-mile can significantly affect last-mile deliveries to end customers [14]. The United States Department of Transportation's (USDOT's) national freight strategic plan anticipates a faster growth rate in overall transport demand for low-weight, high-value commodities than for high-weight, low-value commodities [15]. Such a trend could trigger shifts from trucks to air modes, particularly if significant reductions in operating costs and safety risks can occur through electrification and automation [16; 17]. This has resulted in increasing interest in heavy-lift EAAs for middle-mile services [18]. Recent studies identify reductions in delivery time, cost efficiency, and increased flexibility as primary reasons for cargo EAA adoption [19]. For instance, FedEx is exploring cargo EAAs as potential skyway conveyor belt equivalents among hubs, ramps, and stations [20]. Similarly, UPS has announced plans to utilize EAA for expedited deliveries of time-sensitive commodities [21]. Maersk, the world's largest container shipping line, announced that it will launch an air cargo business to reduce the effects of supply chain disruptions from port logjams, COVID-19 lockdowns, and the crisis in Ukraine [22]. Autonomous trucks can provide a much-needed solution to an industry that has grappled with high driver turnover for nearly five decades [23; 24]. Despite these prospects, the trucking industry faces challenges such as poor roadway conditions, traffic congestion, accidents, weather events, and pressure to decrease pollutive emissions [3; 25]. Therefore, the cost reduction and ongoing performance enhancement of EAA will encourage companies to expand their markets for next-day and same-day deliveries using cargo EAAs [26]. For instance, Amazon aims to extend its one-day or same-day service beyond the 72% of the U.S. population it currently serves [1]. Despite these commercial developments, a recent literature review found a lack of studies on the potential utilities and challenges of cargo EAAs [19]. Much of the literature focuses on short-range EAA applications like monitoring transportation assets [27], providing on-demand air mobility for passengers [28], managing healthcare logistics [29], and conducting direct urban package deliveries [30]. However, the literature offers minimal analysis on the potential utility of EAAs for middle-mile deliveries over extended distances. The literature has explored the broader influences and impacts of EAA adoption in the logistics sector. [PERSON] et al. (2022) found that safety is a main hindrance in the adoption of new transportation technologies [31]. [PERSON] and [PERSON] (2019) found that technological advancements and government regulations are the most influential factors in EAA adoption [32]. [PERSON] et al. (2017) applied text mining to study the social impacts and acceptance of EAA deployments [33]. [PERSON] and [PERSON] (2018) studied how EAA deployments could affect carbon dioxide emissions [34]. [PERSON] et al. (2021) examined how weather might affect EAA delivery services [35]. [PERSON] and [PERSON] (2021) provided some recommendations for urban airspace design to address concerns of noise, safety, capacity, and privacy [36]. Table 1 summarizes the key contributions of these papers and lists the gaps identified relative to the contributions of this study. Anticipating profitable markets for EAA cargo services, numerous aircraft manufacturers have garnered billions in investment to commercialize their designs [37; 38]. Joint research by Deloitte Consulting LLP and the Aerospace Industries Association revealed that the U.S. market for Advanced Air Mobility (AAM) could equal 30% of the U.S. commercial aerospace market in 2019 by 2035, reaching USD 115 billion [39].