**4. Conclusions**

For several years, car manufacturers and governmen<sup>t</sup> agencies have been looking at approaches to enhance road safety and effectively manage traffic flows. With the progress of wireless communication systems, the vision of cars that communicate with each other (V2V) and with systems placed at the edges of roads (V2I), this is becoming a reality. These wireless communication systems for vehicle-to-everything communications (V2X) are collectively known as intelligent transport systems (ITS). The numerous sensors that have been routinely installed on vehicles already detect information on distances to surrounding objects and their speeds. Anyhow, it is well known that the sharing of information from the vehicle to everything around it could allow acknowledging of surrounding situations so that the car driver can practice appropriate countermeasures to avoid accidents or ge<sup>t</sup> into the smoother traffic flow.

In this paper, the concepts for the development of a solution based on V2X communications aimed at vehicle and pedestrian safety have been presented. Regarding a potential system architecture for the development of a real system concerning the safety of vehicles and pedestrians, the drafting of guidelines that could be followed in new applications has been suggested. The primary purpose of this work has not been the introduction of a solution that has already been completed and experimented. As a result, performance evaluation has not been carried out. On the contrary, this paper has aimed at the introduction of the primary insights that a potential application for driver and pedestrian safety should support. To this end, a viable hardware and software architecture that could be employed in vehicles and mobile devices has been presented.

Further effort must be made to address some challenges related to this research field. For instance, the communication systems between vehicles require a stable wireless connection to maximize the transmission capacity of information in order to increase the safety of passengers. The receivers must be able to detect signals even in the worst conditions, e.g., low signal-to-noise ratio, poor modulation quality, and propagation conditions plagued by considerable fading, to ensure an excellent wireless connection. Furthermore, the rapid evolution of systems and components increases the complexity of the design. At the same time, the continuously updated regulations require a more significant number of tests and reliable and accurate results. Test budgets and methodologies fail to keep pace with the speed of innovation, putting pressure on test teams to reach results faster with fewer resources. The test must be able to respond to different types of requirements due to the need to create increasingly complex test systems, and be able to manage different types of measurements and, at the same time, the exponential growth of the collected data. This circumstance is not a problem only for the automotive industry. The same happens in similar sectors, such as heavy vehicles, aerospace, industrial machinery, and research. As a consequence, specific tools are required to optimize the workflow without sacrificing the flexibility to address these challenges.

Some future works concerning V2P applications could focus on mobile-accessible pedestrian signal systems. An application that enables an automatic call from the smartphone of the pedestrian who is blind or has low-vision to the traffic signal could be developed. Further, drivers endeavoring to perform a turn could be warned of the proximity of a pedestrian at the crosswalk. Other research could be performed warning of pedestrians at signalized crosswalks, for instance, developing an application that alerts transportation bus drivers when pedestrians, within the crosswalk of a signalized intersection, are in the expected path of the bus. Other efforts could be performed in investigating systems that can automatically brake a vehicle to avoid hitting a pedestrian, collectively referred

to as pedestrian crash avoidance and mitigation systems. The large-scale dissemination of these methodologies could potentially reduce a considerable percentage of pedestrian crashes.

**Author Contributions:** The authors contributed equally to this work. All authors (G.P., F.A. and A.S.) have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** This work was related to the D.D. 407 of 27 February 2018 "AIM—Attrazione e Mobilità Internazionale" issued by the Italian Ministry of Education, University, and Research in implementation of Action I.2 "Mobilità dei Ricercatori" Asse I— PON R&I 2014–2020, taking into account the written amendment procedure of the PON R&I 2014–2020, pursuant to articles 30 and 90 of Regulation (EU) 1303/2013 started on 21 February 2018 as well as the relevant implementation regulations.

**Conflicts of Interest:** The authors declare no conflict of interest.
