Night Driving and Adverse Weather/Visibility Conditions
What the exam tests
This domain tests speed and lighting choices at night and in fog, rain, snow, smoke, and other low-visibility conditions, with passengers aboard.
Night driving
Use headlights properly, dim the dashboard, and avoid glare. Do not overdrive your headlights: you must be able to stop within the distance you can see. Watch for pedestrians, cyclists, and animals near the road edge.
Fog, rain, and snow
Use low beams in fog, rain, or snow; high beams reflect back and worsen visibility. Reduce speed and increase following distance well beyond the normal formula. Use wipers and defrosters. If visibility becomes unsafe, pull off in a safe place and stop. On wet roads, ease off the accelerator if you feel hydroplaning; do not brake hard. Watch for black ice on bridges and shaded areas.
Worked example
Heavy fog limits visibility to about 100 feet. You should switch to low beams, slow so you can stop within that distance, and increase following distance to well beyond 6 seconds. Reasoning: the normal following formula assumes clear visibility; in fog, visible stopping distance controls your speed.
Traps
- Using high beams in fog.
- Keeping normal following distance in rain.
- Using cruise control on wet roads.
- Driving past the point where you can stop within visible distance.