The two-second rule applies to vehicles traveling under ___ MPH.

• A. 30 MPH
• B. 20 MPH
• C. 40 MPH
• D. 50 MPH

Answer: (A)

Maintaining a safe following distance is essential because your stopping distance grows with speed and reaction time. The two-second rule is a simple way to keep enough space behind the vehicle in front of you at lower speeds. When you’re traveling at speeds under 30 mph, a two-second gap gives you enough time to react and stop if the car ahead suddenly slows or stops.

If you’re going faster than 30 mph, you should increase that gap to three seconds (or more, in adverse conditions) because braking distances are longer and you need more margin to avoid a rear-end collision. To check your distance, pick a fixed object on the road; as the lead vehicle passes it, start counting seconds. If you reach the object before you’ve finished saying two, you’re following too closely.

So the two-second rule is the guideline for speeds under 30 mph; at higher speeds, you should allow more than two seconds. The other speed options imply you’d still be safe with only two seconds, which isn’t correct for those higher speeds.