What guideline is used for determining following distance in good conditions?

The three to four second rule is the guideline used for determining following distance in good driving conditions. This rule suggests that a driver should keep a distance that allows them to safely stop their vehicle within three to four seconds after the vehicle in front of them passes a fixed point. This time frame provides adequate space to react to sudden stops and adjust to the speed of the vehicle ahead, ensuring a safer driving experience.

By maintaining this following distance, drivers can avoid collisions caused by unexpected braking. It's crucial to adapt this rule based on road conditions, weather, and traffic flow, but under ideal conditions, the three to four second gap is widely regarded as a sound practice for safe driving.