## 4 AVs Critical Issues: Aspects Related to Specific Infrastructures Components
### Autonomous Vehicles Detection Capability at Intersection and for Horizontal Road Markings
It is possible to state that the quantity of horizontal markings is related to the roadways context dynamism, meaning that, whenever the possibility of change directions and actors being part of a specific context is elevated, the high quantity of roadway markings will characterize the environment. Therefore, intersections represent a critical issue for marking detection, but for instance, a vital detection challenge for AV sensors is the work area. Work zones are subject to unexpected continuous variations, mainly due to vehicle movement. That is why horizontal markings have a crucial role in implementing a safe work context, especially in highways or freeways where speed ranges are elevated. For these reasons, some studies considered proposing new pavement markings for work zones, as reported in Table 3 and, in some cases, with no predetermined itinerary vehicle so with driver presence. Generally, in a work zone, a significant trial for autonomous vehicles is the reduced lane width between 3.5 and 2 m, if not even less. Different types of barriers or furniture can also be positioned in such lanes that the AV detected as obstacles can cause vehicle sudden stops when is not required. Ultimately, one last critical aspect consists of using various pavement marking materials to cause a high quantity of data collection for AVs when required just the same function or markings detection. Then it would be helpful to the deployment of uniform materials [28]. One aspect that can help solve the aforementioned problems is the lower speed in work zones that allow detection sensors to get better environment perceptions. Therefore, speed range is fundamental [29]. Highways or freeways can be subjected to many conflicts if signals and markings are not efficiently detectable. It has to be highlighted that autonomous vehicles' processes related to environment detection can co-occur to a data management and decision-making process of multiple vehicles handled by a central infrastructural system. Then, it is helpful to apply methods that facilitate the operation previously cited. For example, it is possible to apply protocols related to vehicle intersections behavior based on V2V communication. Some of these protocols are Advanced Maximum Progression Intersection Protocol (AMP-IP) and Maximum Progression Intersection Protocol (MP-IP). MP-IP objective is intersection throughput increase concerning safe crossings until its primary goal of passage safety is satisfied all vehicles are allowed to cross the intersection, also in case of potential conflicts. AMP-IP considers a general conflict cell, allows low-priority cars to cross the intersection before high-priority vehicles arrive [30]. Automated Intersection Management or Intersection Managers (IM) are systems designed to interact with vehicles approaching intersections, aiming to improve traffic safety and efficiency. One of these systems' benefits is that they can reduce the probability of accidents caused by human mistakes, often due to improper driving evaluations or impulsive driving behaviors, due to emotional decisions or instinctive actions rather than logical analysis [31]. Driving reaction times during emergency maneuvers are very short and often will not leave the driver enough time to decide the next move wisely. Automated Intersection Management (IM) systems work by exploiting the communication between vehicles and devices placed on intersections. Vehicles approaching the intersection at constant speed transmit a speed query to the IM, receiving a Yes/No reply depending on other simultaneous requests from other vehicles to optimize flow and manage safety. In case of a positive reply, the incoming vehicle is authorized to proceed and can drive forward, crossing the intersection at the requested constant speed. Should the answer be negative, in that case, the vehicle will slow down and resend new queries to the IM. Once the vehicle crosses the intersection, another signal is sent to the receiving device, communicating that the maneuver has been completed.