Evaluation of a mutual assistance system from both the recipient and assister sides

Abstract

Recently, a number of safety assistance systems for automobiles have been proposed. Most systems aim to assist driving for individual drivers such as auto cruise control (ACC) systems. Our research, however, focuses on a new type of safety assistance system, by which drivers are able to mutually assist each other, based on a “Mutual Assistance” paradigm. The primary purpose of our work is to develop this new paradigm. This paper defines the notion of mutual assistance, and conducts experiments for evaluating our proposed warning assistant system based on that notion. The experiments are done with a driving simulator and conducted for both sides, the recipient driver and the assister driver. In the warning system, the assister driver sends a signal to the recipient driver warning that there are risks of a collision in the case of a right-turn with an oncoming vehicle present (left turn and oncoming vehicle collisions in left hand drive regions). The experiment data of the warning system for recipient drivers includes the collision rate, collision speed, and behavior-specific rates of occurrence for three different warning timings. The results indicate that the warning system statistically decreases the risks of collision in the case of a right-turn with an oncoming vehicle present. The experiment data for assister drivers are the success rate of warning, mental workload (measured with the NASA-TLX) and the attitude change of the driver with manual, semi-automatic, and fully automatic warning systems. The results show that automatic warning has a statistically higher success rate and a lower value for mental workload. On the other hand, semi-automatic or manual warning brings out significant changes in positive attitude. In conclusion, for the recipient-side, this mutual assistance system can provide effective assistance to avoid collisions in the case of a right-turn with an oncoming vehicle present. Also, we have found that appropriate warning timings for early warning alerts are between 1.5s∼2.5s before the collision occurs. Furthermore, a mutual assistance system brings out positive changes of attitude in assistance-side drivers.