Space Management and Hazard Perception
Domain 3 asks whether you can see trouble early and keep enough room to deal with it. The examiner is testing judgement about following distance, scanning and speed choice in poor conditions - the factors behind most single-vehicle and rear-end collisions.
Following distance
Use the two-second rule: when the vehicle ahead passes a fixed object, count two seconds to your own arrival at it. In rain, at night, in blowing snow, or behind a large truck or motorcycle, extend to three or four seconds. At 90 km/h you travel about 25 metres every second, so two seconds is roughly 50 metres - a figure that shrinks fast on ice, where stopping distances can multiply several times over.
Scanning
Look 12 to 15 seconds ahead, not at the bumper in front. Check mirrors every five to eight seconds and shoulder-check before any lane change, because mirrors leave blind spots. Keep out of heavy trucks' four blind zones, especially alongside the cab and directly behind.
Speed choice
A posted limit is a maximum for ideal conditions, not a target. Driving at the limit through fog, freezing rain or a whiteout is an offence if conditions make it unsafe. In blowing snow, use low beams - high beams reflect off the particles and make visibility worse. Look for the tell-tale shine of black ice on bridges, overpasses, shaded stretches and intersection approaches, where it forms first.
Worked example
You are following a pickup at 80 km/h on packed snow and can just complete the two-second count. Is that enough? No. The two-second gap assumes dry pavement and normal reaction time; on packed snow, traction is reduced and braking distance grows, so you drop back to four seconds.
Traps that cost marks
Counting the gap once and never re-checking it; assuming ABS shortens stopping distance on ice (it preserves steering, not grip); using cruise control on slippery surfaces; treating a speed limit as permission rather than a ceiling.