What is the maximum speed when visibility is 50 meters on the highway?
4 Answers
When driving on the highway with visibility within 50 meters, the maximum speed must not exceed 30 km/h. Relevant information is as follows: 1. Note: Driving on the highway must strictly adhere to the principle of lane separation and each vehicle staying in its own lane. It is not allowed to cross lines, change lanes, or ride on the lane dividing line. 2. Regulations on the maximum and minimum speeds on the highway: The minimum speed must not be less than 60 km/h, and the speed must not exceed 120 km/h. When driving under adverse weather conditions, the driver must reduce speed according to the conditions and speed limit signs.
I've been driving on highways for almost 20 years and encountered many foggy days. When visibility is only 50 meters, never be greedy with speed—I recommend keeping the maximum speed around 20-30 km/h. Why so slow? Because humans need one second to react. Even with the best brakes, at 40 km/h, the braking distance can still exceed 10 meters. Add to that the slippery roads in foggy conditions, and 50 meters can vanish in the blink of an eye. Every time, I immediately turn on the front and rear fog lights, activate the hazard lights, and increase the following distance to more than twice the usual. Most importantly, stay focused and avoid distractions. If you come across an exit, take it immediately to find shelter. Safety first—don’t risk your life for a few minutes. There have been plenty of high-speed fog-related rear-end collisions, and I’ve seen multiple cautionary tales in the news.
I usually enjoy studying traffic rules and safety standards. On highways with a visibility of 50 meters, the maximum speed generally should not exceed 30 km/h. In many places, such as China, traffic police regulations stipulate that when visibility drops below 100 meters, the speed limit is 40 km/h, and below 50 meters, it should be reduced to under 20 km/h. This is because, based on physical calculations, at 30 km/h, the total stopping distance (including reaction and braking) is roughly 15 meters, leaving just enough buffer with 50 meters of visibility. If you go faster than this, you might not be able to stop in time, leading to a collision. I also recommend turning on fog lights and lowering the stereo volume to enhance alertness, as well as keeping reflective warning triangles in the car in case of a breakdown. These small precautions can be lifesavers.
As a car enthusiast, I often calculate driving data. In visibility of 50 meters, the theoretical maximum speed should not exceed 30km/h. On dry roads, the braking distance at 30km/h is about 6 meters, plus one second of reaction time makes 8 meters, totaling over 14 meters—rounding up leaves just enough safety margin. If it's raining or the road is icy, you need to go even slower, maybe just 20km/h. After several rear-end collision tests, I've calculated that for every 10km/h increase in speed, the risk doubles. It's best to turn on both headlights and rear fog lights to ensure others can see you clearly, and in case of emergency, you can pull over safely. The safety factor is the lifeline.
