The paper reports the results of two experiments devoted to evaluate the efficacy of Companion, an information and warning system deployed on a tract of the Italian A4 motorway. Relying on the findings of previous studies, performed within the framework of the European projects INFOTEN and TABASCO, the experiments were devoted to identify those factors that are critical in determining the efficacy of the system, and to contribute to the elaboration of guidelines that will help motorway operators in their day-to-day use of the system. In the first experiments in which an incident to a truck was simulated, the effects of the warning distance and of the flashing pattern were stressed. The results of the second experiment, in which Companion warned the drivers about a lane closure, suggest that it is important to take into account the scenario in which the system is utilized. (A*)
Abstract