Effectiveness of color blinking on the detection and recognition distances of bicycles

Introduction. The perception time to detect and recognize the distance of a bicycle is the key reason why drivers look yet fail to determine whether they are within a safe driving distance from the bicycle. Objectives. This study intends to evaluate detection and recognition distance based on the modified color of a bicycle’s tire in four lighting conditions. Methods. The combination of white stripes on a red-colored (WRED) tire was considered for evaluating the detection and recognition distance, and it was compared with three other treatment conditions, i.e., wearing a high-visibility jacket (HVJ), applying reflective tape (RT) to the rear frame and pedal cranks of a bicycle, and wearing a black jacket on a control bicycle (CB). Results. In the straight-ahead approach, the detection and recognition distances were higher for the WRED, within a 250-millisecond (ms) perception time under sunlight and twilight conditions, and were slightly lower in night conditions. Within the 250-ms perception time, the detection and recognition distance of the CB was vulnerable in terms of a safe driving distance (25 m) on a residential road (vehicle speed 30 km/h) under twilight and night conditions. In the left–right-turn approach, the detection and recognition distance of the WRED and HVJ were higher compared with the RT and CB in all conditions. Moreover, the RT was not an effective measure for detection and recognition distance for the left–right-turn approach. Conclusions. Despite the enormous visible area of the HVJ, the color blinking WRED provides a more robust indication of presence within very short perception times under all lighting conditions.