# Road Traffic Gesture Autonomous Integrity Monitoring Using Fuzzy Logic
## 2 Review of Related Work  
The traffic safety improvement strategy in [23] required a combination of roadside controller nodes, short-range devices forming vehicular networks, and intersection-based traffic lights to adapt to changing timing schemes. In this system, the controller nodes set the traffic light phases while the vehicles respond to the changing lights. The introduction of in-vehicle communicating devices allows for the exchange of information through a mobile ad hoc network in place of lane-embedded loop detectors to adapt to its dynamic timing, which comes with significant cost savings. Approaching vehicles exchange information with traffic lights which, in turn, communicate with adjacent traffic lights at other intersections. The most important metrics obtained from these exchanges include control delay and queue length, which are used to generate processes such as phase skipping, extension, or interruption. For want of a better simulator, a discrete Vehicular ad hoc Network (VANET) simulator was developed by integrating vehicular mobility and wireless transmission. The measure of efficiency was performed on existing pre-timed traffic control signals and compared to the adaptive strategy combining the controller nodes, approaching vehicles, and the traffic lights. The adaptive system outperformed the pre-timed system and recorded faster congestion recovery at intersections. Vehicular mobile ad hoc networks can therefore be used in conflict resolution at unsignalized intersections involving autonomous vehicles. Speed adaptation characteristics in autonomous dynamic driving were utilized in [24] to guarantee safe intersection crossing involving a human-driven vehicle and a driverless vehicle. Twenty-four fuzzy rules with four inputs were used to determine the velocity of the autonomous vehicle with respect to that of the driven one. In addition, three inputs were used to establish the exact and relative positions of both vehicles. Though their means of data exchange is not specified, the system is said to receive horizontal and vertical coordinates of both vehicles for analysis carried out in a Takagi-Sugeno-Kang fuzzy inference engine, the implementation of which is also not described outside of the MATLAB environment. To support the lane crossing maneuver at the collision point, two path-tracking models were used to enhance the output speed. Namely, a Proportional Integral Derivative (PID) and a Model Predictive Control (MPC). Based on the Root Mean Squared Error (RMSE) values from both controllers, the MPC was said to improve the intersection crossing maneuver better than the PID controller. Simulation results confirm the success of this approach in varying the speed of the autonomous vehicle appropriately to avoid collision and near-collision incidents. Such a system will be difficult to replicate and implement for conflict resolution in larger, mixed-traffic scenarios. The idea of a Virtual Traffic Light (VTL) was first proposed in [20] as a way to transform roadside traffic lights into an in-vehicle system. It required all vehicles to be furnished with Dedicated Short-Range Communication (DSRC) devices, a digital road map, and a GPS input. Making use of a database to determine the appropriate intersections for VTL activation. The strategy depended on an elected leader among approaching vehicles to play the role of a short-term traffic controller. The stopping distance of the leading vehicle was not established and was assumed to be as close to the intersection as needed. The failure of the leading central controller could subsequently defeat the entire purpose of the self-organized in-vehicle traffic control system, and therefore, a different approach such as the Gesture Autonomous Integrity Monitoring (GAIM) technology is needed. The feasibility of a DSRC-based Virtual Traffic Light (VTL) system was explored in [25]. The use of an On-Board Unit (OBU) was preferred over Road Side Units (RSUs) for its data broadcast.