What is the relationship between visibility and vehicle speed/distance?

[VonWalker]

Here is the relationship between visibility and vehicle speed/distance: 1. When visibility is less than 200 meters: Turn on fog lights, low beams, clearance lights, and front/rear position lights. The speed should not exceed 60 km/h, and maintain a distance of more than 100 meters from the vehicle ahead in the same lane. 2. When visibility is less than 100 meters: Turn on fog lights, low beams, clearance lights, front/rear position lights, and hazard warning flashers. The speed should not exceed 40 km/h, and maintain a distance of more than 50 meters from the vehicle ahead in the same lane. 3. When visibility is less than 50 meters: Turn on fog lights, low beams, clearance lights, front/rear position lights, and hazard warning flashers. The speed should not exceed 20 km/h, and exit the highway from the nearest exit as soon as possible.