Transport is one of the main pillars of modern economies comprising a spectrum of individual systems and their interconnections that are intended to cover the mobility demand of people and goods. Transport systems include an extensive series of physical and organisational elements and are being characterised by an overall intrinsic complexity. These elements can be influencing each other directly and/or indirectly, linearly or nonlinearly, having also potential feedback cycles [1]. In particular, new technologies and transport trends add new levels of interaction with the society and users and may have considerable influence on people mobility and freight transport services. In principle, the transport sector is intrinsically a very dynamic sector, even though conventional transport modes are nowadays consolidated, with mostly evolutionary improvements for what regards their capacity, efficiency, safety, and reliability in the last years. However, transport is also strongly linked to broad societal changes emerging from the ever-changing economies and the geopolitical situation: the global economic crisis, limited resources and new vulnerabilities and uncertainties have a direct impact on the way people and goods move. Within this context, urban freight transport (UFT) is a relevant part of modern cities. It is associated to economic advantages that contribute to well-being but it also generates social costs [2]. So far, more research on UFT and policy interventions have been conducted in Europe, with European cities having to face bigger last-mile challenges due to in general denser urban situations and stricter limits on the use of large trucks in comparison e.g. to the United States [3].
E-commerce, facilitated by the social media marketing, has grown rapidly over the past years. In 2016, the online retailer Amazon was reported to serve 310 million customers worldwide [4]. In Europe, the number of online shoppers can be estimated between 300 and 340 million (estimated by Amazon [5]) and 450 million (calculated from numbers provided by Brohan [6]). As the majority of goods purchased online are delivered directly to customers, last mile delivery (referring to the movement of goods from a transportation hub to their final destination) has become fundamental to this industry. Home deliveries are inefficient due to the spatial dispersion of residences and the frequency of failed deliveries [3] and the cost of delivering parcels represents a significant expenditure for online retailers. For the past 10 years, economic figures reported by Amazon in the US have shown an increasing disproportion between outbound shipping cost and shipping revenue [7]. It is therefore no surprise that the problem of the last mile delivery is now bringing together solutions combining recent developments in Information and Communication Technologies (ICT), Intelligent Transport Systems (ITS), Industry 4.0 and new transport vehicles [8] with the aim to decrease costs. Various solutions, taking into consideration e-consumers’ preferences are being investigated. Among them, automatic delivery stations (lockers) have the potential to reduce home delivery problems (such as missed deliveries) adding advantages such as flexible pick-up time, no missed-deliveries and less travelled kilometres for delivery service providers [9]. Such solutions, already implemented in several countries, may be preferred in dense urban centres where public transport is available. However their associated potential unwanted effects of increasing the number of private vehicles trips to collect the parcels [9] may make them less convenient both in already heavily congested cities and in suburban areas where people are more dependent on cars to move around.
Within this last point, the idea of using Unmanned Aerial Vehicles, or drones, for last mile delivery is gaining popularity. The use of drones to deliver parcels may have the potential to decrease delivery costs, having no driver or truck costs, eliminating congestion costs, having less missed-deliveries due to the very short delay, e.g. 30 min [10] between item dispatch and delivery, and is now the object of intense research activities [11,12,13,14,15,16,17,18,19,20,21]. Drone delivery may bring other significant advantages. From a consumer preference point of view, drone delivery combined with mobile phone applications to ensure traceability and scheduling, could provide conditions to satisfy highest demand probability [9] (combining home delivery with flexible delivery time, information traceability and reduced cost). Drone delivery could also reduce the need for local transport and decrease congestion and air emissions. Some potential issues have also been raised in term of the safety of drones to people and noise (that could potentially be addressed by active noise cancelling [22] or bladeless systems [23]).
Some limitations relative to the use of drone delivery services have been raised particularly for the need to relocate or build new distribution centres closer to customers [14]. A recent patent filled-up by Amazon Technology Inc. [24] for a fulfilment centre (Fig. 1) designed to accommodate landing and take-off of unmanned aerial vehicles in densely populated areas (from here on referred to as drone-beehives) seems to confirm the industry is giving more serious consideration to this delivery alternative.
However, some authors have also suggested that the current hype for drones could lead to false expectations and that the drone delivery concept may not pass the economic viability test. According to the Gartner hype cycle [25], drones spanned the “peak of inflated expectations” in just 1 year, and in 2017, they were about to enter the “trough of disillusionment” [26].
Finally, any innovative logistics solutions should be integrated inside the concept of city logistics [27] considering traffic environment, congestion, safety, and energy savings, and by engaging different stakeholders within the framework of the market economy. The same can be said for the location of urban distribution centers that define the last mile segment: their location should be set by optimizing both long distance freight provision and last mile delivery routings to retailers (including restocking) incorporating economic, environmental and social criteria and constrains [27]. Drone beehives could be established as joined delivery systems where different freight carriers could cooperate to jointly deliver goods to customers and potentially also collect from retailers following a structure presented by Taniguchi [27]. Furthermore, lifecycle analysis should be applied to drone manufacturing and use, as identified in Taniguchi et al. [28], to assess the environmental impact of this technology compared to traditional van delivery.
This paper aims to provide a reality check to the viability of the drone delivery concept. It investigates the potential optimal location of “drone-beehives”, such as the one patented by Amazon and their potential economic viability as a function of the density of reachable population (living at a density low enough to have access to a private landing area i.e. private garden). The objective is to estimate how many EU customers could potentially benefit of this service under and range of different hypothesis. This paper is, to the best of the authors’ knowledge the first to investigate this potential across the EU. The results of this analysis could be incorporated as a possible solution for specific cities as part of further integrated decision support system methodologies (such as proposed by Gatta et al. [2] or Nuzzolo and Comi [29]), as well as for ex-ante policy evaluation [30], to help experts and local authorities develop, evaluate and facilitate appropriate freight and last mile delivery plans for cities.
After a literature review focusing primarily on the drone last mile delivery and pertinent legislative and policy documents in section 2, Section 3 provides an outline of the potential market for the delivery model. Section 4 focuses on modelling hypothesis and details, while, Section 5 provides the model outcomes.