# Agreement Technologies for Coordination in Smart Cities
## 3 Applications
### Coordination of Traffic Flows through Intelligent Intersections  
Removing the human driver from the control loop through the use of autonomous vehicles integrated with an intelligent road infrastructure can be considered as the ultimate, long-term goal of the set of systems and technologies grouped under the name of \"intelligent transportation systems\" (ITS). Autonomous vehicles are already a reality. For instance, in the _DARPA Grand Challenges_ ([[https://en.wikipedia.org/wiki/DARPA_Grand_Challenge](https://en.wikipedia.org/wiki/DARPA_Grand_Challenge)]([https://en.wikipedia.org/wiki/DARPA_Grand_Challenge](https://en.wikipedia.org/wiki/DARPA_Grand_Challenge))), different teams competed to build the best autonomous vehicles, capable of driving in traffic and performing complex manoeuvres such as merging, passing, parking, and negotiating with intersections. The results have shown that autonomous vehicles can successfully interact with both manned and unmanned vehicular traffic in an urban environment. In line with this vision, the _IEEE Connected Vehicles Initiative_ ([[http://sites.ieee.org/connected-vehicles/ieee-connected-vehicles/ieee-cv-initiative/](http://sites.ieee.org/connected-vehicles/ieee-connected-vehicles/ieee-cv-initiative/)]([http://sites.ieee.org/connected-vehicles/ieee-connected-vehicles/ieee-cv-initiative/](http://sites.ieee.org/connected-vehicles/ieee-connected-vehicles/ieee-cv-initiative/))) promotes technologies that link road vehicles to each other and to their physical surroundings (i.e., by vehicle-to-infrastructure and vehicle-to-vehicle wireless communications). The advantages of such an integration span from improved road safety to a more efficient operational use of the transportation network. For instance, vehicles can exchange critical safety information with the infrastructure so as to recognise high-risk situations in advance and therefore to alert drivers. Furthermore, traffic signal systems can communicate signal phase and timing information to vehicles to enhance the use of the transportation network. In this regard, some authors have recently paid attention to the potential of a tighter integration of autonomous vehicles with the road infrastructure for future urban traffic management. In the _reservation-based_ control system [24], an intersection is regulated by a software agent, called _intersection manager_, which assigns reservations of space and time to each autonomous vehicle intending to cross the intersection. Each vehicle is operated by another software agent, called _driver_ agent. When a vehicle approaches an intersection, the driver requests that the intersection manager reserves the necessary space-time slots to safely cross the intersection. The intersection manager, provided with data such as vehicle ID, vehicle size, arrival time, arrival speed, type of turn, and other variables, simulates the vehicle's trajectory inside the intersection and informs the driver whether its request is in conflict with the already confirmed reservations. If such a conflict does not exist, the driver stores the reservation details and tries to meet them; otherwise, it may try again at a later time. The authors show through simulations that in situations of balanced traffic, if all vehicles are autonomous, their delays at the intersection are drastically reduced compared to traditional traffic lights. In this section, we report on our efforts to use different elements of the sandbox of AT to further improve the effectiveness and applicability of [PERSON] and [PERSON]'s approach, assuming a future infrastructure where all vehicles are autonomous and capable of interacting with the regulating traffic infrastructure. We extend the reservation-based model for intersection control at two different levels. * _Single Intersection_: our objective is to elaborate a new policy for the allocation of reservations to vehicles that takes into account the drivers' different attitudes regarding their travel times.