Fog at Night on a Rural Activity Route
You are driving a school activity bus back from a game at 9:15 p.m. on a rural North Dakota two-lane road. There are 30 students aboard, most quiet. Fog has formed quickly; visibility is about 120 feet. The temperature is 33°F, and the pavement looks wet with possible frost in low spots. The speed limit is 55 mph, and deer-crossing signs are posted. Your bus has low-beam headlights, fog lights, and high beams. The center line is visible but the right edge line is faint. A car ahead is 2 seconds away and its taillights disappear into the fog. You must set a safe speed and lighting plan, and decide what to do if the fog thickens.
1. What lighting and speed plan do you use now?
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Use low beams and fog lights if equipped; do not use high beams because they reflect off the fog. Reduce speed so you can stop within the 120 feet you can see - well below 55 mph, likely 25-35 mph depending on pavement and load. Increase following distance to at least 4-6 seconds or more, and do not stare at the taillights ahead. Use the right edge line and center line as guides without drifting. Watch for deer and frosty patches.
2. Fog suddenly drops visibility to about 50 feet. What do you do?
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Slow further and prepare to stop. If you cannot see far enough to stop safely, do not continue at speed. Look for a safe pull-off - a wide shoulder, driveway, or parking lot - rather than stopping in the travel lane. Use hazard lights when stopped or moving slowly as required. Keep students on the bus unless there is a fire or other immediate danger. Notify dispatch. In fog, the goal is to avoid overdriving visibility, not to maintain the speed limit.
3. Why is a 2-second following distance inadequate, and what would you do about the car ahead?
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A 2-second gap is a clear-weather minimum; in fog at 33°F it leaves no margin for the car's sudden braking, for frost, or for a deer. Drop back to 6+ seconds or more. If the car is too close to follow comfortably, slow further and let it gain distance; do not pass in fog. If it stops or slows abruptly, you need space to stop without risking the students.