Night Driving, Adverse Weather, and Mountain Driving with Passengers
Night driving
At night, speed must be limited to what your headlights let you see and stop within. Use low beams in fog, rain, and snow, and when following or meeting traffic. Keep the windshield and mirrors clean, dim the dash, and watch for passengers standing in a dark aisle. Fatigue is a bigger factor at night, so use scheduled breaks.
Adverse weather
Rain, snow, ice, and fog all reduce traction and visibility. Slow down, increase following distance, brake earlier and more gently, and avoid cruise control on wet or icy pavement. On slippery surfaces, switch off retarders and engine brakes. Watch for hydroplaning and for crosswinds that push a high-profile bus. If conditions become unsafe, the correct choice is to stop in a safe place, not to press on.
Mountain driving
On long downgrades, select a low gear before the descent and use engine braking and the retarder to control speed. Do not ride the service brake - brake fade can leave you without stopping power. Use the same gear going down that you would need going up. On upgrades, watch the temperature gauge and downshift early. At altitude, watch for overheating and reduced engine power.
Traps
Questions test gear selection before versus during a descent (before), the use of retarders on ice (off), and headlight use in fog (low beams, not high). Another trap is the claim that a heavier passenger load improves braking - it lengthens stopping distance.
Worked example
Descending a long grade posted for trucks, pick a low gear at the crest, keep the retarder on, and use short service brake applications only if speed still climbs.