Recently, an unusual incident involving an unmanned delivery vehicle unfolded in Hohhot, Inner Mongolia. The vehicle, which was operating autonomously, failed to detect the road construction barriers and traffic cones placed in a designated construction zone, and it proceeded to drive straight into the area. Frustrated on-site workers repeatedly attempted to signal the vehicle to halt, but their efforts were in vain. In a fit of exasperation, they began throwing reflective cones at the vehicle. According to the operator, the vehicle relies on a combination of cameras and LiDAR technology to navigate and perceive its surroundings. However, if the sensor surfaces become contaminated with rainwater or dirt, it can impair the vehicle's ability to recognize and respond to isolation facilities, such as barriers and cones.