The four-second rule helps you maintain at least how many seconds of travel time?

• A. Two seconds of travel time
• B. Four seconds of travel time
• C. One second of travel time
• D. Six seconds of travel time

Answer: (B)

The main idea is using a time-based following distance to ensure you have enough travel time to react and stop if the vehicle in front slows or stops. The four-second rule means you should keep at least four seconds of space between you and the car ahead, which translates to the distance your own car travels in four seconds at your current speed.

This works well because it scales with how fast you’re going. If you drive faster, four seconds covers more ground, giving you more room to see a hazard, react, and brake. In poor weather, on wet or icy roads, or when visibility is low, you should increase that gap even further to compensate for longer stopping distances and slower reaction times.

To check your distance, pick a fixed object ahead and start counting seconds as soon as the vehicle in front passes it. If you reach the object before you’ve finished counting four seconds, you’re too close and need to back off.

Two seconds or one second would leave too little time to react and stop safely, while six seconds is more conservative than the standard guidance for normal conditions.