Hazard awareness
Safe Following Distance, Mirrors, and Blind Spots for BTT
A guide to three-second following gaps, mirror checks, blind spots, signalling, wet roads, cyclists, reversing, and fatigue.
Last reviewed: 1 June 2026. Handbook baseline: 60-66.
Use the three-second rule for a safe following gap in good conditions.
Check mirrors every 5 to 10 seconds while driving.
Check blind spots before moving off, changing lane, or turning where needed.
Study cue
safe driving and hazard awareness
Remember
Use the three-second rule for a safe following gap in good conditions.
Remember
Check mirrors every 5 to 10 seconds while driving.
Remember
Check blind spots before moving off, changing lane, or turning where needed.
Following distance is reaction time
Tailgating is dangerous because it removes the space needed to notice, decide, and brake. The three-second rule gives a practical way to check whether the gap is enough in good conditions.
Choose a fixed point the vehicle ahead passes.
Count three seconds before your vehicle reaches it.
Increase the gap in rain, poor visibility, or heavier traffic risk.
Mirrors are a driving rhythm
Mirror checking is not only for lane changes. The handbook advises checking mirrors regularly while driving, and before actions such as slowing, stopping, turning, overtaking, moving off, or changing lane.
Check mirrors every 5 to 10 seconds while driving.
Check before changing speed or direction.
Use mirrors to understand traffic behind and beside you.
Blind spots catch what mirrors miss
A blind-spot check matters because nearby vehicles, riders, or cyclists may be hidden from mirrors. This is especially important before moving off, changing lanes, turning, or pulling out from parking.
Do not rely on mirrors alone.
Check the blind spot before lateral movement.
Watch for motorcycles and cyclists in narrow gaps.
Hazard awareness includes people and conditions
Safe driving is not only vehicle control. Wet roads, children, elderly pedestrians, cyclists, fatigue, and reversing situations all reduce the margin for error. Good answers usually slow down, increase space, and observe earlier.
Wet roads can increase stopping distance.
Give cyclists at least 1.5 metres where practicable when passing.
Stop and rest if fatigue affects concentration.
Scenario check
Apply the rule before you move on.
These short checks are intentionally close to how test traps feel: one detail changes the answer.
Question
You are following another vehicle closely on a wet road.
Answer
Increase the following gap because stopping distance is longer.
Question
You checked mirrors before changing lane.
Answer
Also check the blind spot before moving.
Question
You feel too tired to concentrate.
Answer
Stop safely and rest before continuing.
Next step
Turn this guide into active recall.
Read the related module for full explanation, then use flashcards to check whether the distinction is actually memorised.
Related topic guides
Road markings
Yellow Lines
A practical guide to single yellow lines, double yellow lines, and yellow zig-zag markings so learners can separate parking restrictions from no-stopping rules.
Special lanes
Bus Lanes
A timetable-style guide to normal bus lanes, full-day bus lanes, bus-only lanes, and the dotted-section turn exception learners often miss.
Legal traps
DIPS
A learner-friendly explanation of the Driver Improvement Points System, probation risk, suspension thresholds, and why some offences go to court.