Final answer:
In conditions of limited visibility, the proper following distance should extend beyond the 3-second rule to 4-5 seconds to factor in increased stopping distances and reduced visibility. Reaction times and the ability to resolve objects such as car headlights at a distance also influence safe following distances.
Step-by-step explanation:
When driving in conditions of limited visibility, such as fog, heavy rain, snow, or at night, it is imperative to maintain a safe following distance from the vehicle in front. This distance is commonly referred to as the 3-second rule, which can be adjusted to 4 or even 5 seconds under adverse weather conditions to ensure sufficient reaction time and stopping distance. It's important to note that stopping distances can vary greatly depending on road conditions and driver reaction time, as highlighted in traffic safety studies.
Driver reaction time is typically assumed to be about 0.5 seconds, and this must be factored into the overall distance required to bring a car to a stop safely. Additionally, the ability to visually resolve objects such as the headlights of a car, which are usually 1.3 meters apart, is crucial when assessing the distance of an oncoming car, especially in relation to the question of when it might be safe to cross a roadway.
In summary, the proper following distance with limited visibility should be increased from the standard 3-second rule to a higher value, providing a buffer that accounts for extended stopping distances and decreased visibility. This helps ensure both safety and compliance with traffic regulations.