Road Safety at Intersections Controlled by Traffic Lights: IVC and Risk Indexes

The paper reports the results of safety analyses conceived to assess the effects and benefits which might be generated by the forthcoming use of the infrastructure-to-vehicle (I2V) or vehicle-to-infrastructure (V2I) communication systems at road intersections regulated by traffic lights. Road crossings are often considered as critical areas for the occurrence of accidents, because they increase the likelihood of the event given the confluence of traffic streams from and to different directions. The analyses are aimed at calculating a real-time estimate of some risk indexes of accident, which might be provided on-board when approaching road intersection regulated by traffic lights. This information can then be used by an ADAS for traffic signal approaching. Two typologies of use of the information on the risk indexes can be identified: if data can be detected in real time, the driver could be informed on-board of a potentially hazardous situation using algorithms to predict the trend of the vehicle on the basis of the data detected from the monitoring; another use would be detecting – in case the vehicle were already within the dilemma zone – the lowest risk manoeuvre and sending a message on board to inform the driver.