# Toward a Modern Last-Mile Delivery: Consequences and Obstacles of Intelligent Technology
## 4 Challenges of Modern LMD  
AI-based technologies enable modern LMD to provide services at any time, increasing customer satisfaction [108], but three types of implementation challenges (named as FFF) must be considered to achieve the best results: facilities, feedback, and frames.  
[PERSON] Facilities  
Facilities is a recurring theme in the included literature, specifically regarding what will happen when the technology is implemented on a larger scale. For one, security is a major concern, particularly in cities [41]. Other security concerns, according to [PERSON] and [PERSON] [87], are cyberattacks and unattended deliveries as drones and robots can be used for good or bad [115]. Storage facility costs and breakdowns are also impediments: without drivers, loading and unloading would be difficult. This would raise the cost of loading and unloading labor [87]. A document [87] on the characteristics of using autonomous goods vehicles for LMD raises the question of what type of existing facillities and standards must be finalized before AI and new LMD businesses can operate efficiently [39]. Facilities are required to implement autonomous vehicles. The concerns and limitations of self-driving delivery systems are discussed [37]. [PERSON], [PERSON], and [PERSON] [37] were concerned about laws, safety, and the functioning of such a delivery system in busy regions where people and robots must share pathways. This type of LMD, according to [PERSON], [PERSON], and [PERSON] [37], would benefit a smaller group of customers in a congested city center. Deliveries in congested city centers may aggravate security and sidewalk-sharing issues, putting a strain on facilities. [PERSON] et al. propose a method for [PERSON] congestion and infrastructure stress [41]. Customers would receive parcels faster with unmanned delivery, resulting in fewer vehicles on the road, according to their research.  
According to [PERSON], [PERSON], and [PERSON], a truck-to-robot system reduces the number of trucks required in a fleet [107]. Congestion may be reduced, resulting in less congested roads. Delivery with sidewalk robotics technology has the potential to reduce the number of vehicles on the road, which would be advantageous in urban areas where externalities are an issue[PERSON] A Colombian startup is making sidewalk deliveries in California. Normally, these robots carry bags of groceries using sensors, radar, cameras, and GPS to navigate and avoid bans and [PERSON]. Sidewalk congestion and pedestrian safety would be negative externalities in urban areas. Due to their limited delivery zones and the need to share sidewalks with other vehicles and pedestrians, [PERSON] and [PERSON] [39] argue that land-based robots should be used in low-traffic areas. The speed of robots on the sidewalk may have an impact on facilities as well. The main challenges of using robots instead of trucks, according to [PERSON], [PERSON], and [PERSON] [106], are range, speed, and available facilities. The robots can travel 6-10 km and deliver at 3-4 km per hour [106]. According to [PERSON], [PERSON], and [PERSON] [90], robots would travel 5-6 km/h on sidewalks, which is faster than the speed estimated by [PERSON], [PERSON], and [PERSON] [106].  
Drones' limited capacity and operating range, as well as congested sidewalks, unpredictable car traffic, and inconvenient delivery and collection of goods, have been criticized by experts [54]. [PERSON], [PERSON], and [PERSON] [29] propose the need for city depots for robots if using a truck and robot system in which the robot does not return to the truck after completing the delivery. This system necessitates the placement of robot depots near delivery points. It is also mentioned that proper facilities and infrastructure for weather and delivery forecasting is required. Snow, sleet, and rain can all have an impact on system efficiency, delay, and safety [116].