ReAR Indicators: Peripheral Cycling Indicators for Rear-Approaching Hazards

During cycling activities, cyclists often focus on pedestrians, vehicles or road conditions in front of their bicycle. Because of this forward focus, approaching vehicles from behind can easily be missed, which can result in accidents, injury, or death. Although rear information can viewed with handle-mounted mirrors or monitors, looking down can distract the cyclist from other hazards. To help address this problem, we present the ReAR Indicator, a peripheral information delivery approach that enhances awareness of rear-approaching vehicles and at the same time preserves forward vision. ReAR uses computer vision applied to a rear-facing RGB-D camera and combines it with position data from a head mounted display for real-time vehicle detection and visualization. Our algorithm delivers information to the periphery such that the user can simultaneously view forward information but still use cues that provide information about hazard distance, width, and probability of collision. Results from a virtual reality based experiment with 20 participants showed that the ReAR Indicator helped cyclists maintain a forward focus while still avoiding collisions with rear-approaching vehicles and in some conditions either matched or outperformed 3D arrows and virtual monitors.