How far ahead should a commercial driver look when driving at highway speeds?

At highway speed, look 12 to 15 seconds ahead, which is roughly a quarter mile, or about one-quarter mile in good visibility. In city driving, 12 to 15 seconds is closer to one and a half blocks. The reason is reaction time: scanning far ahead lets you identify problems early enough to slow, change lanes, or stop without panic braking. Drivers who look only at the vehicle directly ahead get tunnel vision, react late, and tailgate. Looking only as far as the headlights at night is dangerous because at highway speed you can outrun your headlights — high beams reach about 350 feet, but at 55 mph you cover 80 feet per second, leaving little reaction time. The 12-to-15-second rule is independent of speed and works in any condition.