Warning Effect Evaluation and Control for Vehicle Turn Signal Sound

The sound quality of a turn signal sound is directly related to the driving safety and influences comfort during driving. A turn signal sound and interior noise always exist simultaneously while driving. However, none of the studies are performed to observe and control the change of a turn signal sound when the vehicle interior noise was changed. Therefore, this paper develops a method to evaluate and control the warning effect of a turn signal sound masked by vehicle interior noise. First, the turn signal sound and the vehicle interior noise at different speeds are measured and the time-frequency characteristics of the turn signal sound is analyzed. Second, the pairwise comparison method is applied to subjectively evaluate the warning effect of the sounds and the warning effect of the turn signal sound at 6~speeds relative to that at 40~km/h was obtained. Third, a new hearing threshold evaluating the warning effect is developed and used as a sound metric. This metric is employed to evaluate objectively the warning effect of warning sounds at different speeds. The subjective evaluation results are consistent with the objective evaluation results, which confirms the validity of objective evaluation. To keep the warning effect of the warning sound during the driving, two methods of controlling the turn signal sound are proposed and will be researched further in the future.

Using microsimulation and crashes to evaluate the safety of left turn lanes at rural signalized intersections

Left turn movements at intersections can be particularly unsafe. One treatment aimed at making the movement safer is the provision of left turn lanes. However, there is a missing piece in the related research, specifically how the length of left turn lanes impacts the safety of intersections. The Ministry of Transportation Ontario (MTO) has defined this as a high priority research topic. There were two major objectives in this research, both of which were addressed with microsimulation. The first was to determine a relationship between a length of left-turn lanes and safety performance of an intersection, and second was to examine the combined impact of simultaneous installation of left turn lanes with varying lengths and protected left-turn signal phasing. The findings suggested that the longer a left turn lane is, the safer the intersection would be, especially with regard to rear-end crashes.

Using microsimulation and crashes to evaluate the safety of left turn lanes at rural signalized intersections

Left turn movements at intersections can be particularly unsafe. One treatment aimed at making the movement safer is the provision of left turn lanes. However, there is a missing piece in the related research, specifically how the length of left turn lanes impacts the safety of intersections. The Ministry of Transportation Ontario (MTO) has defined this as a high priority research topic. There were two major objectives in this research, both of which were addressed with microsimulation. The first was to determine a relationship between a length of left-turn lanes and safety performance of an intersection, and second was to examine the combined impact of simultaneous installation of left turn lanes with varying lengths and protected left-turn signal phasing. The findings suggested that the longer a left turn lane is, the safer the intersection would be, especially with regard to rear-end crashes.