What is the appropriate speed for driving in foggy conditions?
2 Answers
When driving in foggy conditions, remember to slow down. The thicker the fog, the shorter the visibility distance, and the lower the speed must be. When visibility is less than 200 meters but greater than 100 meters, the speed should not exceed 60 km/h; when visibility is less than 100 meters but greater than 50 meters, the speed should not exceed 40 km/h; when visibility is within 30 meters, the speed should be controlled below 20 km/h; if visibility is less than 10 meters, it is recommended to stop by the roadside and avoid continuing to drive. Things to note when driving in fog: 1. Maintain a safe distance: It is very important to keep a certain distance between vehicles when driving in foggy conditions, as the wet and slippery road surface increases braking distance. Therefore, always increase the distance between your car and the one in front to prevent rear-end collisions in case of sudden braking. 2. Use lights properly: When driving in fog, use front and rear headlights and fog lights appropriately. In heavy fog, turn on hazard lights and width lights to alert other vehicles to yield. Additionally, it's important to note that you should not use high beams when driving in fog. Some people might think high beams provide better illumination, but in reality, because high beams are directed upwards, the light is scattered by the fog, creating a blinding white haze in front of the car that obstructs visibility.
As a veteran long-haul truck driver with 20 years of experience, my biggest fear is suddenly encountering dense fog. I still remember last year when I encountered patchy fog on the Beijing-Tibet Highway - visibility dropped to less than 10 meters. I immediately reduced my speed to under 20 km/h. Why so slow? In thick fog, you can't even see the brake lights of the vehicle ahead when it suddenly stops. At such times, your speed must be lower than the visibility distance to stay safe. While crawling forward with hazard lights on, I noticed all the cars behind me in the rearview mirror were following my lead, voluntarily forming a slow-moving convoy. That experience taught me a lasting lesson: when visibility is 500 meters, keep speed under 60 km/h; at 300 meters visibility, drop to 40 km/h; and if it's less than 100 meters, just find a service area and wait it out.
