The visual lead time on the highway should be about 15 seconds.

Prepare for the California DMV Traffic School Test. Study with interactive quizzes, flashcards, and understand with detailed explanations. Get cleared for your driving confidently!

On highways you need to look far enough ahead to catch changes in traffic and react calmly. About 15 seconds of visual lead time gives you a window to notice slower cars, brake lights, merging traffic, or hazards well before they become urgent, so you can adjust speed and lane position smoothly. At typical highway speeds, 15 seconds equals roughly a quarter of a mile of roadway you’re monitoring, which helps you plan your moves instead of reacting at the last moment. Keep your eyes moving and scan far ahead rather than focusing only on the vehicle in front. If conditions are worse—rain, fog, or slick pavement—increase your lead time by slowing down a bit to maintain a safe buffer. Five seconds is generally too short on the highway, and sixty seconds is impractical, so the guideline of about 15 seconds is the best guide for safe highway driving.