What is the minimum visual lead time to maintain ahead?

What is the minimum visual lead time to maintain ahead?

• A. 6 seconds
• B. 12 seconds
• C. 20 seconds
• D. 30 seconds

Answer: (B)

Visual lead time is the amount of time you have to see and react to hazards ahead of your vehicle. Maintaining at least 12 seconds of lead time gives you a safe margin to notice dangers, assess how they might affect you, and apply braking or steering smoothly without sudden moves. In practice, use the 12-second rule: pick a fixed object on the road, and as the vehicle in front passes it, start counting. If you reach the object before you finish counting to twelve, you’re too close and need to back off until you can reach twelve seconds. Shorter lead times (like six seconds) often don’t provide enough reaction and stopping distance for patrol speeds and conditions; longer times (twenty or thirty seconds) are unnecessarily cautious and can impede traffic.

Visual lead time is the amount of time you have to see and react to hazards ahead of your vehicle. Maintaining at least 12 seconds of lead time gives you a safe margin to notice dangers, assess how they might affect you, and apply braking or steering smoothly without sudden moves. In practice, use the 12-second rule: pick a fixed object on the road, and as the vehicle in front passes it, start counting. If you reach the object before you finish counting to twelve, you’re too close and need to back off until you can reach twelve seconds. Shorter lead times (like six seconds) often don’t provide enough reaction and stopping distance for patrol speeds and conditions; longer times (twenty or thirty seconds) are unnecessarily cautious and can impede traffic.